WO2006129501A1 - Waveguide element - Google Patents

Waveguide element Download PDF

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Publication number
WO2006129501A1
WO2006129501A1 PCT/JP2006/310028 JP2006310028W WO2006129501A1 WO 2006129501 A1 WO2006129501 A1 WO 2006129501A1 JP 2006310028 W JP2006310028 W JP 2006310028W WO 2006129501 A1 WO2006129501 A1 WO 2006129501A1
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WO
WIPO (PCT)
Prior art keywords
light
photonic crystal
incident
inclined surface
dimensional photonic
Prior art date
Application number
PCT/JP2006/310028
Other languages
French (fr)
Japanese (ja)
Inventor
Shigeo Kittaka
Keiji Tsunetomo
Tatsuhiro Nakazawa
Kazuaki Oya
Original Assignee
Nippon Sheet Glass Company, Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Sheet Glass Company, Limited filed Critical Nippon Sheet Glass Company, Limited
Publication of WO2006129501A1 publication Critical patent/WO2006129501A1/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • G02B6/4214—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B6/122—Basic optical elements, e.g. light-guiding paths
    • G02B6/1225—Basic optical elements, e.g. light-guiding paths comprising photonic band-gap structures or photonic lattices
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/43—Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections

Definitions

  • the present invention relates to a waveguide element that uses a one-dimensional photonic crystal as a core.
  • Various optical elements having a structure in which a waveguide is disposed on a substrate have already been put into practical use.
  • a defect waveguide using a two-dimensional photonic crystal (a two-dimensional photonic crystal defect waveguide) has attracted attention, and its research and development has been actively conducted.
  • the structure of this two-dimensional photonic crystal defect waveguide will be described below.
  • a two-dimensional photonic crystal having a two-dimensional refractive index periodic structure is formed by forming regular vacancies in a thin film layer using, for example, Si having a high refractive index.
  • This two-dimensional photonic crystal is configured to form a complete photonic band gap in the operating frequency range in a direction having a refractive index periodicity (refractive index periodic direction).
  • a two-dimensional photonic crystal defect waveguide is formed by providing linear defects in the two-dimensional photonic crystal. Light can propagate through the defect part of this two-dimensional photonic crystal defect waveguide, and cannot propagate through the area where no defect is provided. For this reason, the light entering the defective portion is confined in the defective portion and can propagate without leaking. Therefore, this two-dimensional photonic crystal defect waveguide can be bent at a steep angle (steep angle).
  • this two-dimensional photonic crystal defect waveguide As a wiring, the degree of freedom in designing an optical circuit is increased, and the optical circuit can be downsized or integrated. Further, by using this two-dimensional photonic crystal defect waveguide as a part of the optical element, the optical element can be miniaturized.
  • Waveguide elements using two-dimensional photonic crystals are, for example, Patent Document 1, Patent Document 2, It is disclosed in Patent Literature 3, Patent Literature 4 and Patent Literature 5.
  • an optical circuit including such a waveguide element in combination with an electronic circuit.
  • an optical circuit may be combined with an electronic circuit including a light emitting unit and a light receiving unit. Then, the optical signal output by the light emitting portion of the electronic circuit may be received by the optical circuit, and the optical signal output by the optical circuit force may be received by the light receiving portion of the electronic circuit.
  • a circuit having high-speed processing by the optical circuit and flexible processing by the electronic circuit is configured.
  • FIG. 17A shows a configuration in which an optical circuit and an electronic circuit are end-coupled
  • FIG. 17B shows a configuration in which an optical circuit and an electronic circuit are vertically coupled.
  • the end face coupling means that the end faces of the planar electronic circuit 100 and the planar optical circuit 200 are opposed to each other
  • the vertical coupling is as shown in FIG. 17B.
  • a planar electronic circuit 100 and a planar optical circuit 200 are arranged one above the other and their upper and lower surfaces face each other.
  • the electronic circuit 100 includes a light emitting unit that outputs an optical signal, a light receiving unit that receives the optical signal, and a conductive wire 101
  • the optical circuit 200 includes an output unit that outputs the optical signal and an input unit that receives the optical signal.
  • the end face 102 of the electronic circuit 100 must be provided with a light emitting part and a light receiving part.
  • the end face 201 of the optical circuit 200 must be provided with an output part and an input part. Since the electronic circuit 100 and the optical circuit 200 that input and output the optical signal 300 are planar, the areas of their end faces 102 and 201 are smaller than the areas of the other faces. For this reason, the light emitting part, the light receiving part, the output part, and the input part are arranged in a line, and the number of these light emitting parts is limited.
  • each main surface (upper surface, lower surface) 103, 202 is provided with a light emitting portion, a light receiving portion, an output portion, and an input portion, respectively. Since the main surfaces 103 and 202 have a larger area than the end surfaces 102 and 201, the number of light emitting units, light receiving units, output units, and input units can be increased. That is, the degree of freedom in circuit design increases. Therefore, it is desirable to use vertical coupling when the electronic circuit 100 and the optical circuit 200 are coupled.
  • the emitted light In the case of a planar optical circuit, the emitted light usually travels in a direction parallel to the main surface of the optical circuit and is emitted from the end surface. Therefore, when using vertical coupling, the emitted light must be bent at a right angle.
  • the wavelength demultiplexing element disclosed in Patent Document 5 can resonate a specific frequency component and extract an optical signal having the frequency component in the vertical direction.
  • the optical element disclosed in Patent Document 6 includes a prism and a diffraction grating, the optical path can be bent. Therefore, vertical coupling can be easily realized by using such an optical element.
  • Patent Document 1 JP 2004-212416 A
  • Patent Document 2 JP 2004-170478 A
  • Patent Document 3 Japanese Patent Laid-Open No. 2004-296560
  • Patent Document 4 Japanese Unexamined Patent Application Publication No. 2004-093787
  • Patent Document 5 Japanese Patent Application Laid-Open No. 2004-119671
  • Patent Document 6 International Publication No. 05Z008305 Pamphlet
  • the core diameter is usually not more than 0, which is very small. Therefore, it is difficult to align the optical axis for coupling with external light such as an optical fiber, resulting in a large coupling loss.
  • the emitted light is emitted in a direction suitable for end face coupling (see FIG. 17A).
  • a direction suitable for vertical coupling see Fig. 17B
  • an additional manufacturing process such as obliquely machining the exit end face of the two-dimensional photonic crystal defect waveguide at 45 ° is required. Necessary.
  • an optical signal having the frequency component is vertically
  • the wavelength demultiplexing element that is extracted in the direction cannot simultaneously extract an optical signal including a plurality of frequency components.
  • a waveguide element using a one-dimensional photonic crystal can be easily coupled to an optical fiber because the core diameter of the one-dimensional photonic crystal waveguide is about several ⁇ .
  • the conventional one-dimensional photonic crystal waveguide requires a prism and a diffraction grating in order to be suitable for vertical coupling. And since the size of the waveguide element is about 10 m, it is difficult to actually manufacture the corresponding prism and diffraction grating.
  • the present invention has been made to solve the above-described problems in the prior art, and can be easily manufactured because of its simple structure, can be miniaturized, and can be made suitable for vertical coupling.
  • An object is to provide a waveguide element.
  • the first configuration of the waveguide element according to the present invention has a refractive index periodicity in one direction and a bottom surface perpendicular to the direction having the refractive index periodicity.
  • a photonic crystal which is a core, which is inclined with respect to the bottom surface and an incident side inclined surface and a Z or exit side inclined surface, and corresponds to the incident side inclined surface and the Z or exit side inclined surface.
  • the light input portion causes light to enter the photonic crystal through the bottom surface, and the light incident on the photonic crystal by the light input portion is reflected by the incident side inclined surface, Propagated light due to a band on the Brillouin zone boundary is generated in the photonic crystal, and propagating light due to the band on the Brillouin zone boundary propagating in the photonic crystal is generated at the emission side inclined surface in the light output portion.
  • the light reflected from the bottom surface of the photonic crystal is guided.
  • the first aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an incident side inclined with respect to the bottom surface! /
  • a photonic crystal that is a core having an inclined surface and an outgoing-side inclined surface, and a light input unit and an optical output that are disposed on the bottom surface side of the photonic crystal so as to correspond to the incident-side inclined surface and the outgoing-side inclined surface
  • the light input portion allows light to enter the photonic crystal through the bottom surface.
  • the light incident on the photonic crystal by the light input unit is reflected by the incident-side inclined surface to generate propagating light in a band on the Brillouin zone boundary in the photonic crystal.
  • the propagating light is reflected by the emitting side inclined surface, and the light emitted from the bottom surface of the photonic crystal is guided to the output unit.
  • the second aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an inclined surface inclined with respect to the bottom surface.
  • the light incident on the photonic crystal by the light input unit is reflected by the inclined surface to generate a propagating light by a band on the Brillouin zone boundary in the photonic crystal.
  • the third aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an inclined surface inclined with respect to the bottom surface.
  • the light propagated by the band on the boundary of the prismatic zone is reflected by the inclined surface, and the light emitted from the bottom surface of the photonic crystal is guided.
  • the traveling direction of incident light and Z or emitted light is different from the traveling direction of propagating light. Therefore, a waveguide element suitable for vertical coupling can be realized.
  • the propagating light by the band on the Brillouin zone boundary is used, it can function as a light control element.
  • the waveguide element since a one-dimensional photonic crystal is used, the waveguide element can be easily manufactured because of its simple structure and can be downsized. Can be realized.
  • the reflective layer is preferably made of a metal film or a dielectric multilayer film. Reflective layer If it is made of a metal film, preferably, according to an example, a reflective layer can be easily formed with high reflectivity. Further, according to a preferred example in which the reflective layer is made of a dielectric multilayer film, the reflective layer can be easily formed.
  • the second configuration of the waveguide element according to the present invention has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and faces the bottom surface.
  • the light incident on the photonic crystal is reflected by the incident-side diffraction grating to generate propagating light due to a band on the Brillouin zone boundary in the photonic crystal.
  • Propagating light by band on pre Luan zone boundary to seeding is reflected by the emission side grating, characterized in that is derived light emitted from the bottom surface of the photonic crystal.
  • the first aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface.
  • a photonic crystal that is a core having an incident-side diffraction grating and an output-side diffraction grating, and an optical input disposed on the bottom surface side of the photonic crystal corresponding to the incident-side diffraction grating and the output-side diffraction grating
  • a light output unit wherein the light input unit causes light to enter the photonic crystal through the bottom surface, and the light incident on the photonic crystal by the light input unit is Reflected by the incident side diffraction grating to generate propagating light by a band on the boundary of the Brillouin zone in the photonic crystal, and the propagating light is reflected by the output side diffraction grating at the light output portion, and
  • the bottom of the photonic crystal Is an aspect that the light is guided
  • the second aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface.
  • a photonic crystal as a core having a diffraction grating, and the photonic crystal corresponding to the diffraction grating.
  • a light input portion disposed on a bottom surface side of the crystal, and the light input portion causes light to enter the photonic crystal through the bottom surface, and the light input portion causes the light to enter the photonic crystal.
  • the incident light is reflected by the diffraction grating to generate propagating light by a band on the Brillouin zone boundary in the photonic crystal.
  • a third aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface.
  • a photonic crystal which is a core having a diffraction grating, and a light output unit disposed on the bottom surface side of the photonic crystal so as to correspond to the diffraction grating.
  • the light output unit includes the photonic crystal. The propagating light from the band on the Brillouin zone boundary propagating in the crystal is reflected by the diffraction grating, and the light emitted from the bottom surface of the photonic crystal is guided.
  • the traveling direction of incident light and Z or emitted light is different from the traveling direction of propagating light. Therefore, a waveguide element suitable for vertical coupling can be realized.
  • the propagating light by the band on the Brillouin zone boundary is used, it can function as a light control element.
  • the waveguide element since a one-dimensional photonic crystal is used, the waveguide element can be easily manufactured because of its simple configuration, and can be miniaturized. Can be realized.
  • the traveling direction of light incident on the photonic crystal and the light emitted from the photonic crystal or Z is preferably the same as the direction having the refractive index periodicity of the photonic crystal. According to this preferred example, when this waveguide element is used in an optical circuit, vertical coupling can be easily realized.
  • FIG. 1 is a perspective view showing a configuration of a waveguide element in accordance with the first exemplary embodiment of the present invention.
  • FIG. 2 is a side view showing the configuration of the waveguide element according to the first embodiment of the present invention.
  • FIG. 3 is a side view for explaining the path of light on the incident side in the waveguide element according to the first embodiment of the present invention.
  • FIG. 4 is a band diagram corresponding to FIG.
  • FIG. 5 is a side view for explaining the path of light on the emission side in the waveguide element according to the first embodiment of the present invention.
  • FIG. 6 is a band diagram corresponding to FIG.
  • FIG. 7 is a side view showing a configuration of a waveguide element provided with a reflective layer in the first embodiment of the present invention.
  • FIG. 8 is a side view showing the configuration of the waveguide element according to the second embodiment of the present invention.
  • FIG. 9 is a side view showing the configuration of the waveguide element according to the third embodiment of the present invention.
  • FIG. 10 is a perspective view showing a configuration of a waveguide element in accordance with the fourth exemplary embodiment of the present invention.
  • FIG. 11 is a perspective view showing a specific example in which an optical circuit using a waveguide element according to an embodiment of the present invention and an electronic circuit are combined.
  • FIG. 12 is a side view showing the configuration of the waveguide element in the example of the present invention.
  • FIG. 17A is a perspective view showing a configuration in which an optical circuit and an electronic circuit are end-face coupled in the prior art.
  • FIG. 17B is a perspective view showing a configuration in which an optical circuit and an electronic circuit are vertically coupled in the prior art.
  • FIG. 1 is a perspective view showing the configuration of the waveguide element in the first embodiment of the present invention
  • FIG. 2 is a side view showing the configuration of the waveguide element in the first embodiment of the present invention.
  • the light (electromagnetic wave) propagation direction is the Z-axis direction
  • the directions perpendicular to the light propagation direction (Z-axis direction) and perpendicular to each other are the X-axis direction and V as the Y-axis direction (the same applies to other embodiments described later!).
  • the waveguide element 10 of the present embodiment includes a substrate 1, a one-dimensional photonic crystal 2 provided on the substrate 1, and a one-dimensional photonic crystal 2.
  • a light input unit 3 for allowing light to enter inside and a light output unit 4 for guiding the light emitted from the one-dimensional photonic crystal 2 are provided.
  • the substrate 1 is made of a translucent material.
  • the one-dimensional photonic crystal 2 is composed of a laminated structure in which two types of substances having different refractive indexes are periodically and alternately laminated in the Y-axis direction (the thickness direction of the substrate 1).
  • the thickness of each material constituting the one-dimensional photonic crystal 2 is constant, and therefore the one-dimensional photonic crystal 2 has a refractive index periodicity only in one direction (Y-axis direction).
  • the incident side end face 2a and the emission side end face 2b which are both end faces of the one-dimensional photonic crystal 2, are relative to the XZ plane perpendicular to the Y-axis direction, which is the direction having the refractive index periodicity (refractive index periodic direction) It is inclined by a predetermined angle (inclination angle) (hereinafter, the incident side end surface 2a and the output side end surface 2b that are inclined in this way are referred to as “incident side inclined surface 2a" and “output side inclined surface 2b", respectively. ).
  • the inclination angle of the incident side inclined surface 2a is ⁇
  • the inclination angle of the output side inclined surface 2b is ⁇ .
  • the bottom and top surfaces of the one-dimensional photonic crystal 2 are It is perpendicular to the refractive index periodic direction (Y-axis direction) (parallel to the XZ plane).
  • the optical input unit 3 includes an optical fiber 3 a, a collimator lens 3 b, and an objective lens 3 c, and is disposed on the bottom surface side of the substrate 1.
  • the light input unit 3 causes incident light 5 to enter the bottom surface of the one-dimensional photonic crystal 2 through the substrate 1.
  • the light input unit 3 is arranged so that the incident light 5 travels toward the incident side inclined surface 2a.
  • the light output section 4 also includes an optical fiber 4a, a collimator lens 4b, and an objective lens 4c, and is disposed on the bottom side of the substrate 1.
  • the light reflected by the outgoing side inclined surface 2 b is emitted from the bottom surface of the one-dimensional photonic crystal 2 as outgoing light 6.
  • the light output unit 4 is arranged so that the emitted light 6 is guided to the light output unit 4 through the substrate 1.
  • the light input unit 3 and the light output unit 4 are not limited to such a configuration.
  • the incident angle and the outgoing angle of the incident light 5 and the outgoing light 6 with respect to the substrate 1 are 0 °. That is, it is desirable that the incident light 5 and the outgoing light 6 have the same traveling direction as the refractive index periodic direction of the one-dimensional photonic crystal 2.
  • the one-dimensional photonic crystal 2 is the core of the waveguide, and air and force surrounding the substrate 1, the upper surface and the side surface of the one-dimensional photonic crystal 2, and the waveguide waveguide. It is. Note that a predetermined material can be disposed around the one-dimensional photonic crystal 2 to form a clad.
  • the incident light 5 that has propagated through the optical fiber 3 a is converted into parallel light by the collimator lens 3 b, condensed by the objective lens 3 c, and incident on the substrate 1.
  • Light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the one-dimensional photonic crystal 2 from the bottom surface of the one-dimensional photonic crystal 2.
  • Incident light 5 propagated in the one-dimensional photonic crystal 2 reaches the incident-side inclined surface 2a, is reflected in the Z-axis direction, and propagates in the one-dimensional photonic crystal 2 in the Z-axis direction.
  • the conditions for reflection in the Z-axis direction can be determined from the photonic band structure described later.
  • the propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b.
  • the propagating light 8 is reflected by the inclined surface 2b on the exit side, and the bottom of the one-dimensional photonic crystal 2 Change the course in the direction of the force on the surface (Y-axis direction). Note that the structural force of the photonic band, which will be described later, can be obtained as a condition for reflecting in the axial direction.
  • the light that is reflected by the exit-side inclined surface 2 b of the one-dimensional photonic crystal 2 and becomes the emitted light 6 is emitted from the bottom surface of the one-dimensional photonic crystal 2.
  • the emitted light 6 from the one-dimensional photonic crystal 2 is incident on the substrate 1, propagates through the substrate 1, and is emitted from the substrate 1 to the outside.
  • the emitted light 6 emitted from the substrate 1 is guided to the light output unit 4.
  • the outgoing light 6 emitted from the substrate 1 sequentially passes through the objective lens 4c and the collimating lens 4b and enters the optical fiber 4a.
  • the propagating light 8 propagating in the one-dimensional photonic crystal 2 is desirably propagated by a mode on the Brillouin zone boundary in the photonic band structure, thereby functioning the waveguide element 10 as a light control element. Can be made.
  • the propagating light 8 propagating in the mode on the Brillouin zone boundary is confined in the XZ plane direction regardless of the propagation direction by satisfying the following equation.
  • ⁇ is the wave of propagating light 8 propagating in the one-dimensional photonic crystal 2 in vacuum
  • A is the refractive index period of the one-dimensional photonic crystal 2.
  • N is one dimension
  • the refraction of air Rate as described above, the refraction of air Rate.
  • the confinement condition of the propagating light 8 propagating in the mode on the Brillouin zone boundary in the one-dimensional photonic crystal 2 is disclosed in detail in, for example, International Publication No. 05Z008305 pamphlet.
  • the propagation light 8 in the one-dimensional photonic crystal 2 can be known by calculating a photonic band and illustrating it.
  • the photonic band calculation method is described in “Photonic Crystals, Princeton University Press, (1995)” or “Physical Review B, 1991, 44, No. 16, p.8565”. It is described in detail. Therefore, the inclination angle ⁇ of the incident side inclined surface 2a and the inclination angle ⁇ of the outgoing side inclined surface 2b are determined by the above band a b
  • FIG. 3 illustrates the path of light on the incident side in the waveguide element of the present embodiment.
  • the side view of is shown.
  • FIG. 3 is an enlarged side view showing a configuration in the vicinity of the incident-side inclined surface 2a of the one-dimensional photonic crystal 2.
  • the light input portion is omitted.
  • FIG. 3 when light (incident light 5) from a light input section (not shown) passes through the substrate 1 and enters the one-dimensional photonic crystal 2, it is one-dimensional photonic.
  • Two types of refracted light 7a and 7b leak outside the crystal 2.
  • the light other than the refracted lights 7a and 7b is reflected by the incident side inclined surface 2a and becomes propagating light 8 that travels in the Z-axis direction.
  • FIG. 4 shows a band diagram corresponding to FIG. Figure 4 shows the photo of each of the one-dimensional photonic crystal 2 that is the core, the substrate 1 that is the medium on the incident side of the incident light 5, and the medium that is in contact with the incident side inclined surface 2a (air in this embodiment).
  • the nick band structure is illustrated in the inverse space of the YZ plane.
  • the band diagram of FIG. 4 will be described with reference to FIG.
  • the band of the one-dimensional photonic crystal 2 shows periodicity, as shown in FIG. 4, the band of the one-dimensional photonic crystal 2 is shown by a periodic zone method, and at this frequency. There are a first band and a second band.
  • the broken line 11 represents the boundary between the substrate 1 and the one-dimensional photonic crystal 2
  • the broken line 12 represents the boundary between the air and the one-dimensional photonic crystal 2 (corresponding to the incident side inclined surface 2a).
  • the substrate 1 and air are homogeneous media having a uniform refractive index, and as shown in FIG. 4, the bands indicating them are simple circles.
  • the center point of the band of the substrate 1 is a normal line of the broken line 11 representing the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2.
  • the center point of the air band is the normal line of the broken line 12 representing the boundary between air and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2.
  • the arrows shown in FIG. 4 indicate the energy traveling direction at each of the coupling points A to G on the band, and the energy traveling direction is the normal direction of the band.
  • the incident light 5 on which the substrate 1 side force has also entered is coupled with light from the coupling point A on the second band of the one-dimensional photonic crystal 2.
  • light at the intersection of the line 13 perpendicular to the broken line 12 representing the boundary between the air and the one-dimensional photonic crystal 2 and intersecting the coupling point A and each band propagates in the Y-axis direction at the coupling point A.
  • the incident light 5 incident on the one-dimensional photonic crystal 2 and the propagation mode on the Brillouin zone boundary correspond to the incident-side inclined surface 2a. It is chosen to lie on the same normal of the corresponding dashed line 12. That is, the coupling point A indicating the mode of the incident light 5 and the coupling point B indicating the mode of the propagating light 8 exist on the line 13 orthogonal to the broken line 12.
  • connection points A there are a plurality of coupling points A, these are all equivalent points based on periodicity. The same applies to the connection points B to G other than the connection point A, and the connection points indicated by the same reference numerals represent equivalent points.
  • the light from the coupling point A that is incident on the one-dimensional photonic crystal 2 from the substrate 1 side is reflected by the incident-side inclined surface 2a, and the coupling point B on the Brillouin zone boundary of the first band. Combine with the light.
  • the light incident on the one-dimensional photonic crystal 2 from the substrate 1 side and the light from the coupling point A may be combined with the light at the coupling point C when reflected by the incident side inclined surface 2a.
  • the light from the coupling point A which is the light incident on the one-dimensional photonic crystal 2 from the substrate 1 side, is combined with the light at the coupling point D and the coupling point E when reflected by the incident side inclined surface 2a.
  • the light reflected by the incident side inclined surface 2a is only the light at the coupling point B and the coupling point C.
  • a line 13 that passes through the coupling point A and is perpendicular to the broken line 12 intersects the air band at the coupling point F and the coupling point G. Therefore, the directions indicated by the arrows of the coupling point F and the coupling point G respectively. Refracted lights 7a and 7b are generated on the air side.
  • the light shown in FIG. 4 is as shown below.
  • the light at the coupling point A is propagating light in the same direction as the incident light 5 incident on the substrate 1 side force one-dimensional photonic crystal 2.
  • the light at the coupling point B and the coupling point C is propagating light in the one-dimensional photonic crystal 2 generated by reflection on the incident side inclined surface 2a.
  • the light at the coupling point F and the coupling point G is refracted light 7a and 7b that leaks to the outside from the incident side inclined surface 2a.
  • the light at the coupling point C may be reflected back from the one-dimensional photonic crystal 2 toward the substrate 1 side.
  • FIG. 5 is a side view for explaining the path of light on the emission side in the waveguide element of the present embodiment.
  • Figure 5 shows the configuration of the exit side inclined surface 2b of the one-dimensional photonic crystal 2.
  • FIG. 5 is an enlarged side view, and the light output unit is omitted in FIG.
  • the propagation light 8 in the one-dimensional photonic crystal 2 is reflected by the outgoing inclined surface 2b, and the path is changed to the bottom surface side (substrate 1 side) of the one-dimensional photonic crystal 2.
  • the Outgoing light 6 emitted from the bottom surface of the one-dimensional photonic crystal 2 passes through the substrate 1 and is guided to a light output unit (not shown). Note that two kinds of bending lights 9a and 9b leak to the outside of the one-dimensional photonic crystal 2 on the exit side inclined surface 2b.
  • FIG. 6 shows a band diagram corresponding to FIG. Fig. 6 shows the photo of the one-dimensional photonic crystal 2 that is the core, the substrate 1 that is the medium on the output side of the output light 6, and the medium (air in this embodiment) that is in contact with the output-side inclined surface 2b.
  • the nick band structure is illustrated in the inverse space of the YZ plane.
  • the band diagram of FIG. 6 will be described with reference to FIG.
  • the band of the one-dimensional photonic crystal 2 shows periodicity, as shown in Fig. 6, the band of the one-dimensional photonic crystal 2 is shown by a periodic zone method, and at this frequency.
  • the first band and the second band exist.
  • the broken line 16 represents the boundary between the substrate 1 and the one-dimensional photonic crystal 2
  • the broken line 17 represents the boundary between air and the one-dimensional photonic crystal 2 (corresponding to the outgoing side inclined surface 2b).
  • the substrate 1 and air are homogeneous media having a uniform refractive index, and as shown in Fig. 6, the bands indicating them are simple circles.
  • the center point of the band of the substrate 1 is a normal line of the broken line 16 representing the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2.
  • the center point of the air band is the normal line of the broken line 17 representing the boundary between air and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2.
  • the arrows shown in FIG. 6 indicate the energy traveling directions at each of the coupling points H to M on the band, and the energy traveling direction is the normal direction of the band.
  • connection points H there are a plurality of coupling points H, but these are all equivalent points based on periodicity.
  • connection points I to M other than the connection point H and the connection points indicated by the same reference numerals represent equivalent points.
  • the light that is orthogonal to the broken line 17 representing the boundary between the air and the one-dimensional photonic crystal 2 and intersects the coupling point H and the light at the intersection of each band is the light that couples with the propagating light 8. It is.
  • the light at the coupling point H which is the propagating light 8 on the Brillouin zone boundary, passes through the outgoing inclined surface 2b.
  • the light is reflected and combined with the light at the coupling point I, and becomes the outgoing light 6 that is directly emitted to the outside perpendicularly to the bottom force of the one-dimensional photonic crystal 2.
  • the propagating light 8 is coupled with the light at the coupling point J when reflected by the outgoing side inclined surface 2b.
  • the propagating light 8 is reflected by the exit-side inclined surface 2b, there is a possibility that the propagating light 8 may be combined with the light at the coupling point K. So it can be ignored. Therefore, the light reflected by the emission side inclined surface 2b is only the light at the coupling point I and the coupling point J.
  • the light shown in FIG. 6 is as shown below.
  • Light at the coupling point H is propagating light 8 in the one-dimensional photonic crystal 2.
  • the light at the coupling point I is outgoing light 6 that is reflected by the outgoing side inclined surface 2b and travels toward the substrate 1 side.
  • the light at the coupling point L and the coupling point M is refracted light 9a and 9b that leaks to the outside from the exit-side inclined surface 2b.
  • the light at the coupling point J may be emitted from the one-dimensional photonic crystal 2 toward the substrate 1 side.
  • the light at the junction point J travels differently from the light at the junction point I.
  • the waveguide element 10 of the present embodiment uses light at the coupling point A (incident light 5) and light at the coupling point B (propagation).
  • Light 8 light at coupling point H (propagating light 8) and light at coupling point I (emitted light 6).
  • the light at the coupling point C in FIG. 4 and the light at the coupling point J in FIG. 6 be small. Therefore, for example, in the frequency region where the diameter of the ellipse indicating the second band of the one-dimensional photonic crystal 2 becomes small, the inclination angle ⁇ a and the inclination angle ⁇ are
  • FIG. 7 shows the configuration of a waveguide element provided with a reflective layer in this embodiment.
  • members having the same functions as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.
  • FIG. 7 differs from FIG. 1 and FIG. 2 in that the incident side inclined surface 2a and the emission side inclined surface 2b are different from each other.
  • the point is that the reflective layer 21a and the reflective layer 21b are formed.
  • the reflective layer 21a and the reflective layer 21b are formed.
  • a metal film may be used as the reflective layer 21a and the reflective layer 21b.
  • a material such as silver, aluminum, or gold is particularly desirable as a material for the reflective layer 21a and the reflective layer 21b because it has high reflectivity and can be easily formed.
  • the metal film can be easily formed by, for example, a vacuum deposition method or a sputtering method.
  • a dielectric multilayer film may be used as the reflective layer 21a and the reflective layer 21b.
  • silica, silicon, titanium oxide, tantalum oxide, niobium oxide, magnesium fluoride, silicon nitride, etc. which are generally used as thin film materials and are excellent in terms of durability and film formation cost, etc.
  • Such a material may be used.
  • These materials can be easily formed into thin films by sputtering, vacuum deposition, ion-assisted deposition, plasma CVD, or the like.
  • the traveling directions of the incident light 5 and the outgoing light 6 are substantially perpendicular to the traveling direction of the propagating light 8. Therefore, by using the waveguide element 10 of the present embodiment, an optical circuit suitable for vertical coupling can be realized. In addition, light having a plurality of frequencies can be incident, propagated, and emitted.
  • the waveguide element 10 of the present embodiment can function as a light control element because it uses propagating light that propagates in a mode on the Brillouin zone boundary in the photonic band structure. Furthermore, since the waveguide element 10 of the present embodiment uses the one-dimensional photonic crystal 2, the waveguide element 10 can be easily manufactured because of its simple configuration, and a waveguide element that can be miniaturized can be obtained. Can be realized.
  • FIG. 8 is a side view showing the configuration of the waveguide element according to the second embodiment of the present invention.
  • members having the same functions as those shown in FIG. 2 are given the same reference numerals, and descriptions thereof are omitted.
  • the waveguide element 10a of the present embodiment light from the light input unit 3 (incident light 5) is the same as in the case of the waveguide element 10 of the first embodiment.
  • the bottom force also enters the one-dimensional photonic crystal 2 through the substrate 1. Then, the incident light 5 is reflected by the incident side inclined surface 2 a to become the propagation light 8 and propagates in the one-dimensional photonic crystal 2.
  • the propagating light 8 is emitted through the emission side inclined surface 2b without being reflected by the emission side inclined surface 2b. That is, in the waveguide element 10a shown in FIG. 8, the incident light 5 enters the one-dimensional photonic crystal 2 through the substrate 1, but the emitted light 6a is directly emitted from the emission-side inclined surface 2b.
  • the propagation light 8 is emitted as the emission light 6a from the emission side inclined surface 2b.
  • the light output part 14 to which the outgoing light 6a is guided is arranged facing the outgoing side inclined surface 2b.
  • the light output unit 14 includes an optical fiber 14a, a collimator lens 14b, and an objective lens 14c.
  • the incident light 5 that has propagated through the optical fiber 3 a is converted into parallel light by the collimator lens 3 b, condensed by the objective lens 3 c, and incident on the substrate 1.
  • Light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the one-dimensional photonic crystal 2 from the bottom surface of the one-dimensional photonic crystal 2.
  • Incident light 5 propagated in the one-dimensional photonic crystal 2 reaches the incident-side inclined surface 2a, is reflected in the Z-axis direction, and propagates in the one-dimensional photonic crystal 2 in the Z-axis direction.
  • the propagating light 8 propagating in the one-dimensional photonic crystal 2 is preferably propagated by a mode on the Brillouin zone boundary in the photonic band structure.
  • the incident side inclined surface 2a may be provided with a reflective layer made of, for example, a metal film or a dielectric multilayer film.
  • the propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b.
  • the propagating light 8 is emitted as outgoing light 6a from the outgoing side inclined surface 2b.
  • the outgoing light 6 a emitted from the outgoing side inclined surface 2 b of the one-dimensional photonic crystal 2 is guided to the light output unit 14.
  • the outgoing light 6a emitted from the outgoing side inclined surface 2b of the one-dimensional photonic crystal 2 sequentially passes through the objective lens 14c and the collimating lens 14b and enters the optical fiber 14a.
  • the waveguide element 10a of the present embodiment can achieve the same effects as the waveguide element 10 of the first embodiment.
  • the one-dimensional photonic crystal 2 may not include the exit-side inclined surface 2b. Even if the end face on the exit side of the one-dimensional photonic crystal 2 is a vertical end face, for example, by providing a phase grating on the end face, the propagating light 8 propagating in the mode on the Brillouin zone boundary is transmitted to the light output section 14. Can lead. Further, in the case of a waveguide element in which it is not necessary to take out the emitted light 6, it is not necessary to provide the light output unit 14. For example, in the case of a waveguide element in which incident light 5 is incident for use as control light or excitation light, the attenuation of energy of propagating light 8 may be significant. In such a case, it is not necessary to take out the emitted light 6, and therefore it is not necessary to provide the light output unit 14.
  • Each condition in the waveguide element 10a of the present embodiment may be obtained by band calculation.
  • FIG. 9 is a side view showing the configuration of the waveguide element according to Embodiment 3 of the present invention.
  • members having the same functions as those shown in FIG. 2 are given the same reference numerals, and descriptions thereof are omitted.
  • the propagating light 8 is reflected by the emission side inclined surface 2b. Then, it is emitted as outgoing light 6 through the substrate 1.
  • the incident light 5a is directly incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2a without passing through the substrate 1.
  • Incident light 5 a incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2 a becomes propagating light 8 and propagates in the one-dimensional photonic crystal 2.
  • the incident light 5a is emitted from the incident side inclined surface 2a directly into the one-dimensional photonic crystal 2 and the force-emitted light 6 is emitted through the substrate 1.
  • the incident light 5a is directly incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2a without passing through the substrate 1.
  • the light input section 19 for making the incident light 5 a incident on the one-dimensional photonic crystal 2 faces the incident-side inclined surface 2 a.
  • the light input unit 19 includes an optical fiber 19a, a collimator lens 19b, and an objective lens 19c.
  • the incident light 5a propagating through the optical fiber 19a is collimated by the collimator lens 19b, then condensed by the objective lens 19c, and enters the photonic crystal 2 from the incident side inclined surface 2a.
  • the propagating light 8 propagates through the one-dimensional photonic crystal 2 in the Z-axis direction.
  • the propagating light 8 propagating in the one-dimensional photonic crystal 2 is preferably propagated by a mode on the Brillouin zone boundary in the photonic band structure.
  • the propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b.
  • the propagating light 8 is reflected by the outgoing inclined surface 2b and changes its course in the direction of the direction of force (Y-axis direction) on the bottom surface of the one-dimensional photonic crystal 2.
  • a reflective layer such as a metal film or a dielectric multilayer film may be provided on the outgoing side inclined surface 2b.
  • the light that is reflected by the outgoing side inclined surface 2b of the one-dimensional photonic crystal 2 and becomes the outgoing light 6 is emitted from the bottom surface of the one-dimensional photonic crystal 2.
  • the emitted light 6 from the one-dimensional photonic crystal 2 is incident on the substrate 1, propagates through the substrate 1, and is emitted from the substrate 1 to the outside.
  • the emitted light 6 emitted from the substrate 1 is guided to the light output unit 4.
  • the outgoing light 6 emitted from the substrate 1 sequentially passes through the objective lens 4c and the collimating lens 4b and enters the optical fiber 4a.
  • the light output unit 4 is arranged so that the emitted light 6 is guided to the light output unit 4 through the substrate 1.
  • the waveguide element 10b according to the present embodiment can achieve the same effects as the waveguide element 10 according to the first embodiment.
  • the one-dimensional photonic crystal 2 may not include the incident-side inclined surface 2a. Even if the end face on the incident side of the one-dimensional photonic crystal 2 is a vertical end face, the propagating light 8 can be a propagating light propagating by a mode on the Brillouin zone boundary.
  • a phase grating may be provided on the end face on the incident side of the one-dimensional photonic crystal 2 so that the incident light 5a is incident on the one-dimensional photonic crystal 2 via the phase grating.
  • a waveguide element that does not require incident light to enter there is no need to provide the light input section 19.
  • a waveguide element that uses laser oscillation light generated by external energy as propagating light 8 In the case of a child, it is not necessary to provide the optical input unit 19.
  • Each condition in the waveguide element 10b of the present embodiment may be obtained by band calculation.
  • a waveguide element according to Embodiment 4 of the present invention will be described with reference to the drawings.
  • FIG. 10 is a perspective view showing the configuration of the waveguide element in the fourth exemplary embodiment of the present invention.
  • the waveguide element 30 of the present embodiment and the waveguide element 10 of the first embodiment have substantially the same configuration except that the configuration of the one-dimensional photonic crystal is different. Therefore, in FIG. 10, members having the same functions as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.
  • the waveguide element 30 of the present embodiment includes a substrate 1, a one-dimensional photonic crystal 32 provided on the substrate 1, and light in the one-dimensional photonic crystal 32. And a light output unit 4 through which the light emitted from the one-dimensional photonic crystal 32 is guided.
  • the one-dimensional photonic crystal 32 is composed of a laminated structure in which two kinds of substances having different refractive indexes are periodically and alternately laminated in the Y-axis direction (the thickness direction of the substrate 1).
  • the thickness of each material constituting the one-dimensional photonic crystal 32 is constant, and therefore the one-dimensional photonic crystal 32 has a refractive index periodicity only in one direction (Y-axis direction).
  • an incident side diffraction grating 32a and an emission side diffraction grating 32b are provided at both ends of the upper surface of the one-dimensional photonic crystal 32 (the surface on the opposite side of the substrate 1).
  • incident-side diffraction is formed by forming a plurality of grooves extending in the X-axis direction at equal intervals on the upper surface (a surface parallel to the XZ plane) of the one-dimensional photonic crystal 32 that is a laminated structure.
  • a grating 32a and an output side diffraction grating 32b are provided.
  • the incident light 5 propagating through the optical fiber 3a is converted into parallel light by the collimator lens 3b, then condensed by the objective lens 3c, and incident on the substrate 1.
  • the light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the bottom surface of the one-dimensional photonic crystal 32 (surface facing the top surface) into the one-dimensional photonic crystal 32.
  • the 1D photonic crystal 32 The incident incident light 5 is reflected by the incident-side diffraction grating 32a, and from this, propagation light propagates in the one-dimensional photonic crystal 32 due to the mode on the Brillouin zone boundary in the photonic band structure.
  • the propagating light is reflected by the exit-side diffraction grating 32b, and its path is changed to the bottom surface side (substrate 1 side) of the one-dimensional photonic crystal 32.
  • the outgoing light 6 emitted from the bottom surface of the one-dimensional photonic crystal 32 passes through the substrate 1 and is guided to the light output unit 4.
  • the design of the entrance-side diffraction grating 32a and the exit-side diffraction grating 32b and the design of the one-dimensional photonic crystal 32 are performed using band calculation. This makes it possible to determine the conditions under which the propagating light propagates by the mode on the Brillouin zone boundary.
  • the one-dimensional photonic crystal 32 may include only one of the incident side diffraction grating 32a and the emission side diffraction grating 32b. In that case, the end face of the one-dimensional photonic crystal 32 on which the incident-side diffraction grating 32a or the emission-side diffraction grating 32b is not provided may be an inclined surface. Further, a phase grating may be provided on the end face of the one-dimensional photonic crystal 32, which is provided with the incident side diffraction grating 32a or the emission side diffraction grating 32b. This allows light to be incident into the one-dimensional photonic crystal 32 so that propagating light propagates depending on the mode on the Brillouin zone boundary. It can also be guided.
  • FIG. 11 is a perspective view showing a specific example in which an optical circuit using a waveguide element according to an embodiment of the present invention and an electronic circuit are combined.
  • a lens array 41 in which a plurality of microlenses 4 la are arranged is arranged above the electronic circuit 42. Further, above the lens array 41, an optical circuit 40 including a waveguide element having the same function as the waveguide element of the first embodiment is disposed.
  • the upper surface of the electronic circuit 42 is provided with a VCSEL (Vertical Cavity Semiconductor Emission Laser) 42a and a light receiving cell 42b for emitting an optical signal in the vertical direction.
  • Conductive wire 42c is provided for output.
  • the optical circuit 40 is provided with a plurality of incident-side or emission-side inclined surfaces 40a.
  • the optical circuit 40 includes a one-dimensional photonic crystal, and the inclined surface 40a is formed in the one-dimensional photonic crystal.
  • the microlens 41a corresponds to a light input unit or a light output unit.
  • signal light or control light is output from the VCSEL 42 a toward the lens array 41.
  • the light 43 enters the inclined surface 40a through the microlens 41a.
  • the signal light or the control light is processed by the waveguide element, and is emitted toward the lens array 41 from the inclined surface 40a different from the incident inclined surface 40a.
  • the light 43 is input to the light receiving cell 42b through the microlens 41a.
  • the advantages of both flexible electronic processing and high-speed processing using light can be used. Further, according to the configuration shown in FIG. 11, since the optical circuit 40 and the electronic circuit 42 are arranged separately, the optical circuit 40 and the electronic circuit 42 are manufactured using completely different materials and processes. Can do. That is, the optical circuit 40 and the electronic circuit 42 can be efficiently manufactured without waste. Note that the optical circuit 40 and the electronic circuit 42 may be stacked and integrated on the same substrate.
  • the optical circuit 40 provided with the waveguide element having the same function as the waveguide element of the first embodiment has been described as an example, but the second embodiment to the second embodiment are described. It may be provided with a waveguide element having the same function as the waveguide element of form 4
  • FIG. 12 is a side view showing the configuration of the waveguide element in the example of the present invention.
  • parts having the same functions as those shown in FIGS. 1 and 7 are given the same reference numerals.
  • the one-dimensional photonic crystal 2 that is the core of the waveguide is a Ta 2 O thin film and SiO 2 thin film formed on the upper surface of a parallel flat substrate 1 (100 mm X 20 mm X lmm) that also has quartz force by vacuum evaporation. Are alternately stacked.
  • the thickness of the Ta O thin film is 424 nm, and Si
  • the thickness of the O 2 thin film is 106 nm. These are the forces formed by 10 layers.
  • the thin film of 2 2 functions as the clad 51, and the film thickness is about 2000 nm.
  • the SiO protection as the cladding 51 is formed on the one-dimensional photonic crystal 2 having the nine-layer structure.
  • the refractive index period of the one-dimensional photonic crystal 2 is 530 ⁇ m.
  • the optical characteristics were measured for two cases where the width (length in the X-axis direction) of the one-dimensional photonic crystal 2 was 10 mm and the length L of the one-dimensional photonic crystal 2 was 24.5 mm and 39.5 mm. went.
  • both end surfaces of the one-dimensional photonic crystal 2 are cut obliquely so that the angles (tilt angles) formed by the XZ plane, the incident side inclined surface 2a, and the output side inclined surface 2b are 27 °, respectively. It is a polished surface.
  • reflective layers 21a and 21b made of silver having a thickness of 150 nm are formed on the incident side inclined surface 2a and the emission side inclined surface 2b by a vacuum deposition method, respectively.
  • the collimator lens 3b which is a spherical lens, is converted into a parallel light beam.
  • the light input unit 3 transmits the parallel light beam by an objective lens 3c which is a cylindrical plano-convex lens (material is optical glass B K7, center thickness 3.8 mm, focal length 3.9 mm) having a curvature radius of 2. Omm. Convert to linear focus.
  • This linear focal point is incident perpendicular to the bottom surface of the one-dimensional photonic crystal 2 (a plane parallel to the XZ plane). That is, the angle between the bottom surface of the one-dimensional photonic crystal 2 and the optical axis of the incident light 5 is 90 °.
  • the focal point is linear because the one-dimensional photonic crystal 2 that becomes the core of the waveguide has a slab shape.
  • the SMFs (optical fibers 3a and 4a) on the incident side and the outgoing side are connected to an optical vector analyzer (OVA-CT type manufactured by Lun a Technologies Inc., USA), and the optical characteristics of the waveguide element 50 (JO All elements of the corn matrix were evaluated. [0113] The measurement results of this example are shown below.
  • the optical axes of the incident light 5 and the outgoing light 6 are set to be perpendicular to the substrate 1 (the substrate 1 for the incident light 5 and the outgoing light 6). It is possible to easily change the incident angle and the outgoing angle by changing the paths of the incident light 5 and the outgoing light 6.
  • a waveguide element suitable for vertical coupling can be realized. Therefore, by mounting this waveguide element on an optical circuit and combining the optical circuit and the electronic circuit, a circuit that takes advantage of the advantages of the optical circuit and the electronic circuit can be manufactured.

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Abstract

A waveguide element (10) comprising a photonic crystal (2) which is a core exhibiting unidirectional periodicity of refractive index and having a bottom face perpendicular to the periodic direction of refractive index and an incoming side inclined surface (2a) and an outgoing side inclined surface (2b) inclining against the bottom face, a light input portion (3), and a light output portion (4). The light input portion (3) lets the light into the photonic crystal (2) through the bottom face. The light entered into the photonic crystal (2) is reflected off the incoming side inclined surface (2a) and propagation light is generated in the photonic crystal (2) by a band on the Brillouin zone boundary. The propagation light is reflected off the outgoing side inclined surface (2b) and the light exits from the bottom face of the photonic crystal (2). The outgoing light from the photonic crystal (2) is led to the light output portion (4). Fabrication is facilitated because of simple structure, and a small waveguide element suitable for vertical coupling can be provided.

Description

明 細 書  Specification
導波路素子  Waveguide element
技術分野  Technical field
[0001] 本発明は、 1次元フォトニック結晶をコアとして用いる導波路素子に関する。  The present invention relates to a waveguide element that uses a one-dimensional photonic crystal as a core.
背景技術  Background art
[0002] 基板上に導波路を配置した構成の光学素子、すなわち、導波路素子は、すでに種 々実用化されている。特に、最近、 2次元フォトニック結晶を用いた欠陥導波路（2次 元フォトニック結晶欠陥導波路）が注目され、その研究開発が盛んに行われている。 以下、この 2次元フォトニック結晶欠陥導波路の構造について説明する。まず、高屈 折率の例えば Siを用いた薄膜層に規則的な空孔を形成することにより、 2次元の屈 折率周期構造を有する 2次元フォトニック結晶が構成される。尚、この 2次元フォト-ッ ク結晶は、屈折率周期性を有する方向 (屈折率周期方向）において、使用周波数域 における完全フォトニックバンドギャップを形成するように構成される。そして、この 2 次元フォトニック結晶に線状の欠陥を設けることにより、 2次元フォトニック結晶欠陥導 波路が構成される。光は、この 2次元フォトニック結晶欠陥導波路の欠陥部分を伝播 することができ、欠陥が設けられていない個所を伝播することはできない。このため、 欠陥部分に入った光は、当該欠陥部分に閉じ込められ、漏れることなく伝播すること ができる。従って、この 2次元フォトニック結晶欠陥導波路は、急峻な角度 (急角度） で曲げることが可能である。そして、この 2次元フォトニック結晶欠陥導波路を配線とし て用いることにより、光回路の設計の自由度が高くなり、当該光回路の小型化又は集 積ィ匕が可能となる。また、この 2次元フォトニック結晶欠陥導波路を光学素子の一部と して用いることにより、光学素子の小型化が可能となる。  [0002] Various optical elements having a structure in which a waveguide is disposed on a substrate, that is, waveguide elements, have already been put into practical use. In particular, recently, a defect waveguide using a two-dimensional photonic crystal (a two-dimensional photonic crystal defect waveguide) has attracted attention, and its research and development has been actively conducted. The structure of this two-dimensional photonic crystal defect waveguide will be described below. First, a two-dimensional photonic crystal having a two-dimensional refractive index periodic structure is formed by forming regular vacancies in a thin film layer using, for example, Si having a high refractive index. This two-dimensional photonic crystal is configured to form a complete photonic band gap in the operating frequency range in a direction having a refractive index periodicity (refractive index periodic direction). A two-dimensional photonic crystal defect waveguide is formed by providing linear defects in the two-dimensional photonic crystal. Light can propagate through the defect part of this two-dimensional photonic crystal defect waveguide, and cannot propagate through the area where no defect is provided. For this reason, the light entering the defective portion is confined in the defective portion and can propagate without leaking. Therefore, this two-dimensional photonic crystal defect waveguide can be bent at a steep angle (steep angle). By using this two-dimensional photonic crystal defect waveguide as a wiring, the degree of freedom in designing an optical circuit is increased, and the optical circuit can be downsized or integrated. Further, by using this two-dimensional photonic crystal defect waveguide as a part of the optical element, the optical element can be miniaturized.
[0003] さらに、この 2次元フォトニック結晶欠陥導波路内を伝播する光に群速度異常を生 じさせることも可能である。従って、この 2次元フォトニック結晶欠陥導波路を光学素 子の一部として用いた場合に、非線型作用を大きくして、光学素子の特性を改善した り、サイズを小さくしたりすることができる。  [0003] Furthermore, it is possible to cause a group velocity abnormality in the light propagating in the two-dimensional photonic crystal defect waveguide. Therefore, when this two-dimensional photonic crystal defect waveguide is used as a part of an optical element, the nonlinear effect can be increased to improve the characteristics of the optical element and reduce the size. .
[0004] 2次元フォトニック結晶を用いた導波路素子は、例えば、特許文献 1、特許文献 2、 特許文献 3、特許文献 4及び特許文献 5に開示されている。尚、実際には、上記 2次 元フォトニック結晶欠陥導波路と、伝播損失の小さい単純なシリコン細線導波路とを 組み合わせた導波路を用いるのが一般的である。 [0004] Waveguide elements using two-dimensional photonic crystals are, for example, Patent Document 1, Patent Document 2, It is disclosed in Patent Literature 3, Patent Literature 4 and Patent Literature 5. In practice, it is common to use a waveguide that is a combination of the two-dimensional photonic crystal defect waveguide and a simple silicon wire waveguide with small propagation loss.
[0005] また、 2次元フォトニック結晶に比べて構成が簡単であるために容易に作製すること ができる、 1次元フォトニック結晶を用いた導波路素子も提案されている（例えば、特 許文献 6参照)。 [0005] Further, a waveguide element using a one-dimensional photonic crystal that can be easily manufactured because of its simpler structure than a two-dimensional photonic crystal has been proposed (for example, patent literature). 6).
[0006] また、このような導波路素子を含む光回路と、電子回路とを結合して用いることが提 案されている。具体的には、光回路と、発光部及び受光部を備えた電子回路とを組 み合わせればよい。そして、電子回路の発光部力 出力された光信号を光回路で受 信し、光回路力 出力された光信号を電子回路の受光部で受信するようにすればよ い。このように、光回路と電子回路とを結合させることにより、光回路による高速処理と 電子回路によるフレキシブルな処理とを備えた回路が構成される。  [0006] Further, it has been proposed to use an optical circuit including such a waveguide element in combination with an electronic circuit. Specifically, an optical circuit may be combined with an electronic circuit including a light emitting unit and a light receiving unit. Then, the optical signal output by the light emitting portion of the electronic circuit may be received by the optical circuit, and the optical signal output by the optical circuit force may be received by the light receiving portion of the electronic circuit. In this way, by combining the optical circuit and the electronic circuit, a circuit having high-speed processing by the optical circuit and flexible processing by the electronic circuit is configured.
[0007] 光回路と電子回路とを結合させる場合、一般的に、端面結合と垂直結合の 2種類 の結合が考えられる。図 17Aに、光回路と電子回路とを端面結合させた構成を示し、 図 17Bに、光回路と電子回路とを垂直結合させた構成を示す。端面結合とは、図 17 Aに示すように、平面状の電子回路 100と平面状の光回路 200との端面同士を対向 させたものであり、垂直結合とは、図 17Bに示すように、平面状の電子回路 100と平 面状の光回路 200とを上下に配置し、それらの上面、下面同士を対向させたもので ある。ここで、電子回路 100は、光信号を出力する発光部と光信号を受信する受光部 と導線 101とを備え、光回路 200は、光信号を出力する出力部と光信号を受信する 入力部とを備えている。  [0007] When coupling an optical circuit and an electronic circuit, generally, two types of coupling, that is, end surface coupling and vertical coupling, can be considered. FIG. 17A shows a configuration in which an optical circuit and an electronic circuit are end-coupled, and FIG. 17B shows a configuration in which an optical circuit and an electronic circuit are vertically coupled. As shown in FIG. 17A, the end face coupling means that the end faces of the planar electronic circuit 100 and the planar optical circuit 200 are opposed to each other, and the vertical coupling is as shown in FIG. 17B. A planar electronic circuit 100 and a planar optical circuit 200 are arranged one above the other and their upper and lower surfaces face each other. Here, the electronic circuit 100 includes a light emitting unit that outputs an optical signal, a light receiving unit that receives the optical signal, and a conductive wire 101, and the optical circuit 200 includes an output unit that outputs the optical signal and an input unit that receives the optical signal. And.
[0008] 図 17Aに示す端面結合においては、電子回路 100の端面 102に、発光部及び受 光部が設けられていなければならない。また同様に、光回路 200の端面 201に、出 力部及び入力部が設けられていなければならない。光信号 300の入出力を行う電子 回路 100及び光回路 200は平面状であることから、それらの端面 102、 201の面積 は他の面の面積よりも小さい。このため、発光部及び受光部と出力部及び入力部と は一列配置となり、これら発光部等の個数が制限されてしまう。  In the end face coupling shown in FIG. 17A, the end face 102 of the electronic circuit 100 must be provided with a light emitting part and a light receiving part. Similarly, the end face 201 of the optical circuit 200 must be provided with an output part and an input part. Since the electronic circuit 100 and the optical circuit 200 that input and output the optical signal 300 are planar, the areas of their end faces 102 and 201 are smaller than the areas of the other faces. For this reason, the light emitting part, the light receiving part, the output part, and the input part are arranged in a line, and the number of these light emitting parts is limited.
[0009] これに対して、図 17Bに示す垂直結合においては、電子回路 100及び光回路 200 のそれぞれの主面（上面、下面） 103、 202に、発光部及び受光部と出力部及び入 力部とがそれぞれ設けられる。そして、主面 103、 202は端面 102、 201に比べて面 積が大きいため、発光部及び受光部と出力部及び入力部との個数を多くすることが できる。つまり、回路設計上の自由度が大きくなる。従って、電子回路 100と光回路 2 00とを結合させる場合には、垂直結合を用いるのが望ま 、。 On the other hand, in the vertical coupling shown in FIG. 17B, the electronic circuit 100 and the optical circuit 200 Each main surface (upper surface, lower surface) 103, 202 is provided with a light emitting portion, a light receiving portion, an output portion, and an input portion, respectively. Since the main surfaces 103 and 202 have a larger area than the end surfaces 102 and 201, the number of light emitting units, light receiving units, output units, and input units can be increased. That is, the degree of freedom in circuit design increases. Therefore, it is desirable to use vertical coupling when the electronic circuit 100 and the optical circuit 200 are coupled.
[0010] 平面状の光回路の場合、出射光は、通常、光回路の主面と平行な方向に進行し、 端面から出射される。従って、垂直結合を用いる場合には、出射光を直角に曲げる 必要がある。例えば、特許文献 5に開示されている波長分波素子は、特定の周波数 成分を共振させて、その周波数成分を有する光信号を垂直方向に取り出すことがで きる。また、例えば、特許文献 6に開示されている光学素子は、プリズムや回折格子 を備えているため、光路を曲げることができる。従って、このような光学素子を用いるこ とにより、垂直結合を容易に実現することができる。 [0010] In the case of a planar optical circuit, the emitted light usually travels in a direction parallel to the main surface of the optical circuit and is emitted from the end surface. Therefore, when using vertical coupling, the emitted light must be bent at a right angle. For example, the wavelength demultiplexing element disclosed in Patent Document 5 can resonate a specific frequency component and extract an optical signal having the frequency component in the vertical direction. For example, since the optical element disclosed in Patent Document 6 includes a prism and a diffraction grating, the optical path can be bent. Therefore, vertical coupling can be easily realized by using such an optical element.
特許文献 1：特開 2004 - 212416号公報  Patent Document 1: JP 2004-212416 A
特許文献 2：特開 2004 - 170478号公報  Patent Document 2: JP 2004-170478 A
特許文献 3：特開 2004 - 296560号公報  Patent Document 3: Japanese Patent Laid-Open No. 2004-296560
特許文献 4:特開 2004— 093787号公報  Patent Document 4: Japanese Unexamined Patent Application Publication No. 2004-093787
特許文献 5：特開 2004 - 119671号公報  Patent Document 5: Japanese Patent Application Laid-Open No. 2004-119671
特許文献 6：国際公開第 05Z008305号パンフレット  Patent Document 6: International Publication No. 05Z008305 Pamphlet
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0011] ここで、シリコン細線導波路又は上記した 2次元フォトニック結晶欠陥導波路の場合 、そのコア径は、通常 0. 以下となり、非常に小さい。そのため、光ファイバなど の外部光と結合させるための光軸合わせが困難であり、結合損失が大きくなる。  [0011] Here, in the case of the silicon fine wire waveguide or the above-described two-dimensional photonic crystal defect waveguide, the core diameter is usually not more than 0, which is very small. Therefore, it is difficult to align the optical axis for coupling with external light such as an optical fiber, resulting in a large coupling loss.
[0012] また、これらの導波路を平面状の光回路上に配置すると、出射光は端面結合（図 1 7A参照）に適した方向に出射される。出射光を垂直結合（図 17B参照）に適した方 向に出射させるためには、例えば、 2次元フォトニック結晶欠陥導波路の出射側端面 を 45° に斜め加工する等の製造工程の追加が必要となる。  [0012] When these waveguides are arranged on a planar optical circuit, the emitted light is emitted in a direction suitable for end face coupling (see FIG. 17A). In order to emit the emitted light in a direction suitable for vertical coupling (see Fig. 17B), for example, an additional manufacturing process such as obliquely machining the exit end face of the two-dimensional photonic crystal defect waveguide at 45 ° is required. Necessary.
[0013] また、特定の周波数成分を共振させて、その周波数成分を有する光信号を垂直方 向に取り出す上記波長分波素子は、複数の周波数成分を含む光信号を同時に取り 出すことができない。 [0013] Further, by resonating a specific frequency component, an optical signal having the frequency component is vertically The wavelength demultiplexing element that is extracted in the direction cannot simultaneously extract an optical signal including a plurality of frequency components.
[0014] また、 1次元フォトニック結晶を用いた導波路素子は、 1次元フォトニック結晶導波路 のコア径が数 πι程度であるため、光ファイバと容易に結合させることができる。しか し、従来の 1次元フォトニック結晶導波路では、垂直結合に適したものとするために、 プリズムや回折格子が必要となる。そして、導波路素子のサイズが 10 m程度である ため、それに対応するプリズムや回折格子を実際に作製することは困難である。  [0014] Further, a waveguide element using a one-dimensional photonic crystal can be easily coupled to an optical fiber because the core diameter of the one-dimensional photonic crystal waveguide is about several πι. However, the conventional one-dimensional photonic crystal waveguide requires a prism and a diffraction grating in order to be suitable for vertical coupling. And since the size of the waveguide element is about 10 m, it is difficult to actually manufacture the corresponding prism and diffraction grating.
[0015] 本発明は、従来技術における前記課題を解決するためになされたものであり、構成 が簡単であるために容易に作製することができ、小型化が可能で、垂直結合に適し た導波路素子を提供することを目的とする。 [0015] The present invention has been made to solve the above-described problems in the prior art, and can be easily manufactured because of its simple structure, can be miniaturized, and can be made suitable for vertical coupling. An object is to provide a waveguide element.
課題を解決するための手段  Means for solving the problem
[0016] 前記目的を達成するため、本発明に係る導波路素子の第 1の構成は、一方向に屈 折率周期性を有し、前記屈折率周期性を有する方向に対して垂直な底面と、前記底 面に対して傾斜している入射側傾斜面及び Z又は出射側傾斜面とを有する、コアで あるフォトニック結晶と、前記入射側傾斜面及び Z又は出射側傾斜面に対応させて 前記フォトニック結晶の底面側に配置された光入力部及び Z又は光出力部とを備えIn order to achieve the above object, the first configuration of the waveguide element according to the present invention has a refractive index periodicity in one direction and a bottom surface perpendicular to the direction having the refractive index periodicity. And a photonic crystal, which is a core, which is inclined with respect to the bottom surface and an incident side inclined surface and a Z or exit side inclined surface, and corresponds to the incident side inclined surface and the Z or exit side inclined surface. A light input part and a Z or light output part arranged on the bottom side of the photonic crystal
、前記光入力部は、前記フォトニック結晶内に前記底面を介して光を入射させ、前記 光入力部によって前記フォトニック結晶内に入射された光は、前記入射側傾斜面で 反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンドによる伝播光を 生じさせ、前記光出力部には、前記フォトニック結晶内を伝播するブリルアンゾーン 境界上のバンドによる伝播光が前記出射側傾斜面で反射して、前記フォトニック結晶 の前記底面から出射された光が導かれることを特徴とする。 The light input portion causes light to enter the photonic crystal through the bottom surface, and the light incident on the photonic crystal by the light input portion is reflected by the incident side inclined surface, Propagated light due to a band on the Brillouin zone boundary is generated in the photonic crystal, and propagating light due to the band on the Brillouin zone boundary propagating in the photonic crystal is generated at the emission side inclined surface in the light output portion. The light reflected from the bottom surface of the photonic crystal is guided.
[0017] この導波路素子の第 1の構成の態様としては、以下の 3つが考えられる。  [0017] The following three forms of the first configuration of the waveguide element are conceivable.
[0018] 第 1の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対して傾斜して!/、る入射側傾斜面及び出射側傾 斜面とを有する、コアであるフォトニック結晶と、前記入射側傾斜面及び出射側傾斜 面に対応させて前記フォトニック結晶の底面側に配置された光入力部及び光出力部 とを備え、前記光入力部は、前記フォトニック結晶内に前記底面を介して光を入射さ せ、前記光入力部によって前記フォトニック結晶内に入射された光は、前記入射側 傾斜面で反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンドによる 伝播光を生じさせ、前記光出力部には、前記伝播光が前記出射側傾斜面で反射し て、前記フォトニック結晶の前記底面から出射される光が導かれるという態様である。 [0018] The first aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an incident side inclined with respect to the bottom surface! / A photonic crystal that is a core having an inclined surface and an outgoing-side inclined surface, and a light input unit and an optical output that are disposed on the bottom surface side of the photonic crystal so as to correspond to the incident-side inclined surface and the outgoing-side inclined surface And the light input portion allows light to enter the photonic crystal through the bottom surface. The light incident on the photonic crystal by the light input unit is reflected by the incident-side inclined surface to generate propagating light in a band on the Brillouin zone boundary in the photonic crystal. In this aspect, the propagating light is reflected by the emitting side inclined surface, and the light emitted from the bottom surface of the photonic crystal is guided to the output unit.
[0019] 第 2の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対して傾斜している傾斜面とを有する、コアである フォトニック結晶と、前記傾斜面に対応させて前記フォトニック結晶の底面側に配置さ れた光入力部とを備え、前記光入力部は、前記フォトニック結晶内に前記底面を介し て光を入射させ、前記光入力部によって前記フォトニック結晶内に入射された光は、 前記傾斜面で反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンド による伝播光を生じさせると 、う態様である。  [0019] The second aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an inclined surface inclined with respect to the bottom surface. A photonic crystal that is a core, and a light input portion disposed on a bottom surface side of the photonic crystal so as to correspond to the inclined surface, and the light input portion includes the bottom surface in the photonic crystal. The light incident on the photonic crystal by the light input unit is reflected by the inclined surface to generate a propagating light by a band on the Brillouin zone boundary in the photonic crystal. This is the aspect.
[0020] 第 3の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対して傾斜している傾斜面とを有する、コアである フォトニック結晶と、前記傾斜面に対応させて前記フォトニック結晶の底面側に配置さ れた光出力部とを備え、前記光出力部には、前記フォトニック結晶内を伝播するプリ ルアンゾーン境界上のバンドによる伝播光が前記傾斜面で反射して、前記フォト-ッ ク結晶の前記底面から出射される光が導かれるという態様である。  [0020] The third aspect has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and an inclined surface inclined with respect to the bottom surface. A photonic crystal that is a core, and a light output unit disposed on a bottom surface side of the photonic crystal so as to correspond to the inclined surface, and the light output unit propagates through the photonic crystal In this embodiment, the light propagated by the band on the boundary of the prismatic zone is reflected by the inclined surface, and the light emitted from the bottom surface of the photonic crystal is guided.
[0021] 前記本発明の導波路素子の第 1の構成によれば、入射光及び Z又は出射光の進 行方向と伝播光の進行方向とが異なる。従って、垂直結合に適した導波路素子を実 現することができる。また、この導波路素子の第 1の構成によれば、ブリルアンゾーン 境界上のバンドによる伝播光を用いるものであるため、光制御素子として機能させる ことができる。また、この導波路素子の第 1の構成によれば、 1次元フォトニック結晶が 用いられているので、構成が簡単であるために容易に作製することができ、小型化が 可能な導波路素子を実現することができる。  [0021] According to the first configuration of the waveguide element of the present invention, the traveling direction of incident light and Z or emitted light is different from the traveling direction of propagating light. Therefore, a waveguide element suitable for vertical coupling can be realized. In addition, according to the first configuration of the waveguide element, since the propagating light by the band on the Brillouin zone boundary is used, it can function as a light control element. Further, according to the first configuration of this waveguide element, since a one-dimensional photonic crystal is used, the waveguide element can be easily manufactured because of its simple structure and can be downsized. Can be realized.
[0022] また、前記本発明の導波路素子の第 1の構成においては、前記入射側傾斜面及 び Z又は出射側傾斜面に、反射層が形成されているのが好ましい。この好ましい例 によれば、光の損失を減少させて、結合効率を大きくすることができる。また、この場 合には、前記反射層が金属膜又は誘電体多層膜からなるのが好ましい。反射層が 金属膜からなると 、う好ま 、例によれば、容易に反射率の高!、反射層を形成するこ とができる。また、反射層が誘電体多層膜からなるという好ましい例によれば、容易に 反射層を形成することができる。 [0022] In the first configuration of the waveguide element of the present invention, it is preferable that a reflection layer is formed on the incident side inclined surface and the Z or output side inclined surface. According to this preferred example, it is possible to reduce the light loss and increase the coupling efficiency. In this case, the reflective layer is preferably made of a metal film or a dielectric multilayer film. Reflective layer If it is made of a metal film, preferably, according to an example, a reflective layer can be easily formed with high reflectivity. Further, according to a preferred example in which the reflective layer is made of a dielectric multilayer film, the reflective layer can be easily formed.
[0023] また、本発明に係る導波路素子の第 2の構成は、一方向に屈折率周期性を有し、 前記屈折率周期性を有する方向に対して垂直な底面と、前記底面に対向する上面 と、前記上面に設けられた入射側回折格子及び Z又は出射側回折格子とを有する、 コアであるフォトニック結晶と、前記入射側回折格子及び Z又は出射側回折格子に 対応させて前記フォトニック結晶の底面側に配置された光入力部及び Z又は光出力 部とを備え、前記光入力部は、前記フォトニック結晶内に前記底面を介して光を入射 させ、前記光入力部によって前記フォトニック結晶内に入射された光は、前記入射側 回折格子で反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンドに よる伝播光を生じさせ、前記光出力部には、前記フォトニック結晶内を伝播するプリ ルアンゾーン境界上のバンドによる伝播光が前記出射側回折格子で反射して、前記 フォトニック結晶の前記底面から出射された光が導かれることを特徴とする。 The second configuration of the waveguide element according to the present invention has a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, and faces the bottom surface. A photonic crystal that is a core, and the incident side diffraction grating and the Z or exit side diffraction grating provided on the upper surface, and the incident side diffraction grating and the Z or exit side diffraction grating. A light input portion and a Z or light output portion arranged on the bottom side of the photonic crystal, and the light input portion causes light to enter the photonic crystal through the bottom surface, and the light input portion The light incident on the photonic crystal is reflected by the incident-side diffraction grating to generate propagating light due to a band on the Brillouin zone boundary in the photonic crystal. Inside the photonic crystal Propagating light by band on pre Luan zone boundary to seeding is reflected by the emission side grating, characterized in that is derived light emitted from the bottom surface of the photonic crystal.
[0024] この導波路素子の第 2の構成の態様としては、以下の 3つが考えられる。  [0024] The following three configurations are conceivable as modes of the second configuration of the waveguide element.
[0025] 第 1の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対向する上面と、前記上面に設けられた入射側回 折格子及び出射側回折格子とを有する、コアであるフォトニック結晶と、前記入射側 回折格子及び出射側回折格子に対応させて前記フォトニック結晶の底面側に配置さ れた光入力部及び光出力部とを備え、前記光入力部は、前記フォトニック結晶内に 前記底面を介して光を入射させ、前記光入力部によって前記フォトニック結晶内に入 射された光は、前記入射側回折格子で反射して、前記フォトニック結晶内にブリルァ ンゾーン境界上のバンドによる伝播光を生じさせ、前記光出力部には、前記伝播光 が前記出射側回折格子で反射して、前記フォトニック結晶の前記底面から出射され る光が導かれるという態様である。 [0025] The first aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface. A photonic crystal that is a core having an incident-side diffraction grating and an output-side diffraction grating, and an optical input disposed on the bottom surface side of the photonic crystal corresponding to the incident-side diffraction grating and the output-side diffraction grating And a light output unit, wherein the light input unit causes light to enter the photonic crystal through the bottom surface, and the light incident on the photonic crystal by the light input unit is Reflected by the incident side diffraction grating to generate propagating light by a band on the boundary of the Brillouin zone in the photonic crystal, and the propagating light is reflected by the output side diffraction grating at the light output portion, and The bottom of the photonic crystal Is an aspect that the light is guided that will be emitted from.
[0026] 第 2の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対向する上面と、前記上面に設けられた回折格子 とを有する、コアであるフォトニック結晶と、前記回折格子に対応させて前記フォト-ッ ク結晶の底面側に配置された光入力部とを備え、前記光入力部は、前記フォトニック 結晶内に前記底面を介して光を入射させ、前記光入力部によって前記フォトニック結 晶内に入射された光は、前記回折格子で反射して、前記フォトニック結晶内にブリル アンゾーン境界上のバンドによる伝播光を生じさせるという態様である。 [0026] The second aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface. A photonic crystal as a core having a diffraction grating, and the photonic crystal corresponding to the diffraction grating. A light input portion disposed on a bottom surface side of the crystal, and the light input portion causes light to enter the photonic crystal through the bottom surface, and the light input portion causes the light to enter the photonic crystal. The incident light is reflected by the diffraction grating to generate propagating light by a band on the Brillouin zone boundary in the photonic crystal.
[0027] 第 3の態様は、一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に 対して垂直な底面と、前記底面に対向する上面と、前記上面に設けられた回折格子 とを有する、コアであるフォトニック結晶と、前記回折格子に対応させて前記フォト-ッ ク結晶の底面側に配置された光出力部とを備え、前記光出力部には、前記フォトニッ ク結晶内を伝播するブリルアンゾーン境界上のバンドによる伝播光が前記回折格子 で反射して、前記フォトニック結晶の前記底面から出射される光が導かれるという態 様である。  [0027] A third aspect is provided with a refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, and the top surface. A photonic crystal, which is a core having a diffraction grating, and a light output unit disposed on the bottom surface side of the photonic crystal so as to correspond to the diffraction grating. The light output unit includes the photonic crystal. The propagating light from the band on the Brillouin zone boundary propagating in the crystal is reflected by the diffraction grating, and the light emitted from the bottom surface of the photonic crystal is guided.
[0028] 前記本発明の導波路素子の第 2の構成によれば、入射光及び Z又は出射光の進 行方向と伝播光の進行方向とが異なる。従って、垂直結合に適した導波路素子を実 現することができる。また、この導波路素子の第 2の構成によれば、ブリルアンゾーン 境界上のバンドによる伝播光を用いるものであるため、光制御素子として機能させる ことができる。また、この導波路素子の第 2の構成によれば、 1次元フォトニック結晶が 用いられているので、構成が簡単であるために容易に作製することができ、小型化が 可能な導波路素子を実現することができる。  [0028] According to the second configuration of the waveguide element of the present invention, the traveling direction of incident light and Z or emitted light is different from the traveling direction of propagating light. Therefore, a waveguide element suitable for vertical coupling can be realized. In addition, according to the second configuration of this waveguide element, since the propagating light by the band on the Brillouin zone boundary is used, it can function as a light control element. Further, according to the second configuration of this waveguide element, since a one-dimensional photonic crystal is used, the waveguide element can be easily manufactured because of its simple configuration, and can be miniaturized. Can be realized.
[0029] また、前記本発明の導波路素子の第 1又は第 2の構成においては、前記フォト-ッ ク結晶内に入射される光の進行方向及び Z又は前記フォトニック結晶から出射され る光の進行方向が、前記フォトニック結晶の前記屈折率周期性を有する方向と同一 であるのが好ましい。この好ましい例によれば、この導波路素子を光回路に用いた場 合に、垂直結合を容易に実現することができる。  [0029] In the first or second configuration of the waveguide element of the present invention, the traveling direction of light incident on the photonic crystal and the light emitted from the photonic crystal or Z The traveling direction of the photonic crystal is preferably the same as the direction having the refractive index periodicity of the photonic crystal. According to this preferred example, when this waveguide element is used in an optical circuit, vertical coupling can be easily realized.
発明の効果  The invention's effect
[0030] 本発明によれば、構成が簡単であるために容易に作製することができ、小型化が可 能で、垂直結合に適した導波路素子を提供することができる。  [0030] According to the present invention, it is possible to provide a waveguide element that can be easily manufactured because of its simple configuration, can be miniaturized, and is suitable for vertical coupling.
図面の簡単な説明  Brief Description of Drawings
[0031] [図 1]図 1は、本発明の実施の形態 1における導波路素子の構成を示す斜視図であ る。 FIG. 1 is a perspective view showing a configuration of a waveguide element in accordance with the first exemplary embodiment of the present invention. The
[図 2]図 2は、本発明の実施の形態 1における導波路素子の構成を示す側面図であ る。  FIG. 2 is a side view showing the configuration of the waveguide element according to the first embodiment of the present invention.
[図 3]図 3は、本発明の実施の形態 1の導波路素子における、入射側の光の進路を説 明するための側面図である。  FIG. 3 is a side view for explaining the path of light on the incident side in the waveguide element according to the first embodiment of the present invention.
[図 4]図 4は、図 3に対応するバンド図である。  FIG. 4 is a band diagram corresponding to FIG.
[図 5]図 5は、本発明の実施の形態 1の導波路素子における、出射側の光の進路を説 明するための側面図である。  FIG. 5 is a side view for explaining the path of light on the emission side in the waveguide element according to the first embodiment of the present invention.
[図 6]図 6は、図 5に対応するバンド図である。  FIG. 6 is a band diagram corresponding to FIG.
[図 7]図 7は、本発明の実施の形態 1における反射層を備えた導波路素子の構成を 示す側面図である。  FIG. 7 is a side view showing a configuration of a waveguide element provided with a reflective layer in the first embodiment of the present invention.
[図 8]図 8は、本発明の実施の形態 2における導波路素子の構成を示す側面図であ る。  FIG. 8 is a side view showing the configuration of the waveguide element according to the second embodiment of the present invention.
[図 9]図 9は、本発明の実施の形態 3における導波路素子の構成を示す側面図であ る。  FIG. 9 is a side view showing the configuration of the waveguide element according to the third embodiment of the present invention.
[図 10]図 10は、本発明の実施の形態 4における導波路素子の構成を示す斜視図で ある。  FIG. 10 is a perspective view showing a configuration of a waveguide element in accordance with the fourth exemplary embodiment of the present invention.
[図 11]図 11は、本発明の一実施の形態における導波路素子を用いた光回路と、電 子回路とを組み合わせた具体例を示す斜視図である。  FIG. 11 is a perspective view showing a specific example in which an optical circuit using a waveguide element according to an embodiment of the present invention and an electronic circuit are combined.
[図 12]図 12は、本発明の実施例における導波路素子の構成を示す側面図である。  FIG. 12 is a side view showing the configuration of the waveguide element in the example of the present invention.
[図 13]図 13は、本発明の実施例における、 L (l次元フォトニック結晶の長さ） = 24. 5mmの場合のインパルス応答を示すグラフである。 FIG. 13 is a graph showing an impulse response when L (length of a one-dimensional photonic crystal) = 24.5 mm in an example of the present invention.
[図 14]図 14は、本発明の実施例における、 L = 39. 5mmの場合のインパルス応答を 示すグラフである。  FIG. 14 is a graph showing an impulse response when L = 39.5 mm in an example of the present invention.
[図 15]図 15は、本発明の実施例における、 L = 24. 5mmの場合の挿入損失を示す グラフである。  FIG. 15 is a graph showing the insertion loss when L = 24.5 mm in the example of the present invention.
[図 16]図 16は、本発明の実施例における、 L = 39. 5mmの場合の挿入損失を示す グラフである。 [図 17A]図 17Aは、従来技術における、光回路と電子回路とを端面結合させた構成 を示す斜視図である。 FIG. 16 is a graph showing insertion loss when L = 39.5 mm in an example of the present invention. [FIG. 17A] FIG. 17A is a perspective view showing a configuration in which an optical circuit and an electronic circuit are end-face coupled in the prior art.
[図 17B]図 17Bは、従来技術における、光回路と電子回路とを垂直結合させた構成 を示す斜視図である。  FIG. 17B is a perspective view showing a configuration in which an optical circuit and an electronic circuit are vertically coupled in the prior art.
符号の説明 Explanation of symbols
1 基板  1 Board
2、 32 1次元フォトニック結晶  2, 32 1D photonic crystal
2a 入射側傾斜面  2a Incident side inclined surface
2b 出射側傾斜面  2b Output side inclined surface
3、 19 光入力部  3, 19 Optical input section
3a、 4a、 14a、 19a 光ファイノく  3a, 4a, 14a, 19a
3b、 4b、 14b、 19b コリメータレンズ  3b, 4b, 14b, 19b collimator lens
3c、 4c、 14c、 19c 対物レンズ  3c, 4c, 14c, 19c objective lens
4、 14 光出力部  4, 14 Optical output section
5、 5a 入射光  5, 5a Incident light
6、 6a 出射光  6, 6a Outgoing light
8 伝播光  8 Propagating light
10、 10a, 10b、 30、 50 導波路素子  10, 10a, 10b, 30, 50 Waveguide element
21a, 21b 反射層 21a, 21b Reflective layer
32a 入射側回折格子 32a Incident side diffraction grating
32b 出射側回折格子 32b Outgoing diffraction grating
40 光回路 40 Optical circuit
0a 傾斜面  0a Inclined surface
41 レンズ了レイ 41 Lens End Ray
1a マイクロレンズ  1a micro lens
42 電子回路 42 Electronic circuit
2a VCSEL 2a VCSEL
2b 受光セル 42c 導線 2b Photosensitive cell 42c conductor
43 光  43 Light
51 クラッド、  51 clad,
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0033] 以下、実施の形態を用いて本発明をさらに具体的に説明する。  Hereinafter, the present invention will be described more specifically with reference to embodiments.
[0034] [実施の形態 1]  [0034] [Embodiment 1]
本発明の実施の形態 1における導波路素子について、図を参照しながら説明する 。図 1は、本発明の実施の形態 1における導波路素子の構成を示す斜視図、図 2は、 本発明の実施の形態 1における導波路素子の構成を示す側面図である。尚、図 1、 図 2においては、光 (電磁波）の伝播方向を Z軸方向とし、光の伝播方向（Z軸方向） に対して垂直で、かつ、それぞれ互いに垂直な方向を X軸方向及び Y軸方向として V、る（後述する他の実施の形態にお!、ても同様である)。  A waveguide element according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the waveguide element in the first embodiment of the present invention, and FIG. 2 is a side view showing the configuration of the waveguide element in the first embodiment of the present invention. 1 and 2, the light (electromagnetic wave) propagation direction is the Z-axis direction, the directions perpendicular to the light propagation direction (Z-axis direction) and perpendicular to each other are the X-axis direction and V as the Y-axis direction (the same applies to other embodiments described later!).
[0035] 図 1、図 2に示すように、本実施の形態の導波路素子 10は、基板 1と、基板 1上に設 けられた 1次元フォトニック結晶 2と、 1次元フォトニック結晶 2内に光を入射させる光 入力部 3と、 1次元フォトニック結晶 2から出射された光が導かれる光出力部 4とを備え ている。ここで、基板 1は、透光性の材料により構成されている。  As shown in FIGS. 1 and 2, the waveguide element 10 of the present embodiment includes a substrate 1, a one-dimensional photonic crystal 2 provided on the substrate 1, and a one-dimensional photonic crystal 2. A light input unit 3 for allowing light to enter inside and a light output unit 4 for guiding the light emitted from the one-dimensional photonic crystal 2 are provided. Here, the substrate 1 is made of a translucent material.
[0036] 1次元フォトニック結晶 2は、屈折率の異なる 2種類の物質が Y軸方向（基板 1の厚さ 方向）に周期的に交互に積層されて構成された積層構造体からなる。 1次元フォト- ック結晶 2を構成する各物質の層厚は一定であり、このため、 1次元フォトニック結晶 2 は、一方向（Y軸方向）にのみ屈折率周期性を有する。また、 1次元フォトニック結晶 2 の両端面である入射側端面 2a及び出射側端面 2bは、屈折率周期性を有する方向（ 屈折率周期方向）である Y軸方向に垂直な XZ平面に対して所定の角度 (傾斜角度） だけ傾斜している（以下、このように傾斜している入射側端面 2a及び出射側端面 2b を、それぞれ「入射側傾斜面 2a」及び「出射側傾斜面 2b」という）。入射側傾斜面 2a の傾斜角度は Φ 、出射側傾斜面 2bの傾斜角度は φ である。また、入射側傾斜面  [0036] The one-dimensional photonic crystal 2 is composed of a laminated structure in which two types of substances having different refractive indexes are periodically and alternately laminated in the Y-axis direction (the thickness direction of the substrate 1). The thickness of each material constituting the one-dimensional photonic crystal 2 is constant, and therefore the one-dimensional photonic crystal 2 has a refractive index periodicity only in one direction (Y-axis direction). Also, the incident side end face 2a and the emission side end face 2b, which are both end faces of the one-dimensional photonic crystal 2, are relative to the XZ plane perpendicular to the Y-axis direction, which is the direction having the refractive index periodicity (refractive index periodic direction) It is inclined by a predetermined angle (inclination angle) (hereinafter, the incident side end surface 2a and the output side end surface 2b that are inclined in this way are referred to as "incident side inclined surface 2a" and "output side inclined surface 2b", respectively. ). The inclination angle of the incident side inclined surface 2a is Φ, and the inclination angle of the output side inclined surface 2b is φ. In addition, incident side inclined surface
a b  a b
2a及び出射側傾斜面 2bの傾斜の方向は、互いに逆向きである。尚、傾斜角度 φ  The directions of inclination of 2a and the outgoing side inclined surface 2b are opposite to each other. Inclination angle φ
a 及び傾斜角度 Φ  a and tilt angle Φ
bは互いに異なる値であってもよいが、同一の値とした方が、設計及 び製造が容易となって望ましい。また、 1次元フォトニック結晶 2の底面及び上面は、 屈折率周期方向 (Y軸方向）に対して垂直 (XZ平面に平行)である。 Although b may be different from each other, it is preferable to use the same value because it is easier to design and manufacture. The bottom and top surfaces of the one-dimensional photonic crystal 2 are It is perpendicular to the refractive index periodic direction (Y-axis direction) (parallel to the XZ plane).
[0037] 光入力部 3は、光ファイバ 3aとコリメータレンズ 3bと対物レンズ 3cとを備えており、基 板 1の底面側に配置されている。この光入力部 3は、基板 1を介して、入射光 5を 1次 元フォトニック結晶 2の底面に入射させる。この場合、光入力部 3は、入射光 5が、入 射側傾斜面 2aに向力つて進行するように配置されている。 The optical input unit 3 includes an optical fiber 3 a, a collimator lens 3 b, and an objective lens 3 c, and is disposed on the bottom surface side of the substrate 1. The light input unit 3 causes incident light 5 to enter the bottom surface of the one-dimensional photonic crystal 2 through the substrate 1. In this case, the light input unit 3 is arranged so that the incident light 5 travels toward the incident side inclined surface 2a.
[0038] また、光出力部 4も、光ファイバ 4aとコリメータレンズ 4bと対物レンズ 4cとを備えてお り、基板 1の底面側に配置されている。出射側傾斜面 2bで反射した光が出射光 6とし て 1次元フォトニック結晶 2の底面から出射される。この場合、光出力部 4は、出射光 6 が基板 1を介して光出力部 4に導かれるように配置されている。 The light output section 4 also includes an optical fiber 4a, a collimator lens 4b, and an objective lens 4c, and is disposed on the bottom side of the substrate 1. The light reflected by the outgoing side inclined surface 2 b is emitted from the bottom surface of the one-dimensional photonic crystal 2 as outgoing light 6. In this case, the light output unit 4 is arranged so that the emitted light 6 is guided to the light output unit 4 through the substrate 1.
[0039] 尚、光入力部 3及び光出力部 4は、このような構成に限定されるものではない。 Note that the light input unit 3 and the light output unit 4 are not limited to such a configuration.
[0040] また、入射光 5及び出射光 6の基板 1に対する入射角及び出射角は 0° であるのが 望ましい。すなわち、入射光 5及び出射光 6は、その進行方向が 1次元フォトニック結 晶 2の屈折率周期方向と同一であるのが望ましい。これにより、導波路素子 10を光回 路に用いた場合に、垂直結合を容易に実現することができる。 [0040] Further, it is desirable that the incident angle and the outgoing angle of the incident light 5 and the outgoing light 6 with respect to the substrate 1 are 0 °. That is, it is desirable that the incident light 5 and the outgoing light 6 have the same traveling direction as the refractive index periodic direction of the one-dimensional photonic crystal 2. Thereby, when the waveguide element 10 is used in an optical circuit, vertical coupling can be easily realized.
[0041] 以上のような構成において、 1次元フォトニック結晶 2は導波路のコアであり、基板 1 と、 1次元フォトニック結晶 2の上面及び側面を取り囲んでいる空気と力 導波路のク ラッドである。尚、 1次元フォトニック結晶 2の周りに所定の材料を配置することによつ てクラッドとすることちできる。 [0041] In the configuration as described above, the one-dimensional photonic crystal 2 is the core of the waveguide, and air and force surrounding the substrate 1, the upper surface and the side surface of the one-dimensional photonic crystal 2, and the waveguide waveguide. It is. Note that a predetermined material can be disposed around the one-dimensional photonic crystal 2 to form a clad.
[0042] 次に、本実施の形態の導波路素子 10の動作について説明する。 Next, the operation of the waveguide element 10 according to the present embodiment will be described.
[0043] まず、光ファイバ 3aを伝播してきた入射光 5は、コリメータレンズ 3bで平行光とされ た後、対物レンズ 3cで集光されて、基板 1に入射される。光入力部 3からの光 (入射 光 5)は、基板 1内を伝播した後、 1次元フォトニック結晶 2内に、 1次元フォトニック結 晶 2の底面から入射される。 1次元フォトニック結晶 2内を伝播した入射光 5は、入射 側傾斜面 2aに到達して Z軸方向に反射し、 1次元フォトニック結晶 2内を Z軸方向に 伝播する。尚、 Z軸方向に反射する条件は、後述するフォトニックバンドの構造から求 めることができる。 First, the incident light 5 that has propagated through the optical fiber 3 a is converted into parallel light by the collimator lens 3 b, condensed by the objective lens 3 c, and incident on the substrate 1. Light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the one-dimensional photonic crystal 2 from the bottom surface of the one-dimensional photonic crystal 2. Incident light 5 propagated in the one-dimensional photonic crystal 2 reaches the incident-side inclined surface 2a, is reflected in the Z-axis direction, and propagates in the one-dimensional photonic crystal 2 in the Z-axis direction. The conditions for reflection in the Z-axis direction can be determined from the photonic band structure described later.
[0044] 1次元フォトニック結晶 2内を Z軸方向に伝播している伝播光 8は、出射側傾斜面 2b に到達する。伝播光 8は、出射側傾斜面 2bで反射して、 1次元フォトニック結晶 2の底 面に向力 方向（Y軸方向）へ進路を変更する。尚、 Υ軸方向に反射する条件は、後 述するフォトニックバンドの構造力も求めることができる。 [0044] The propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b. The propagating light 8 is reflected by the inclined surface 2b on the exit side, and the bottom of the one-dimensional photonic crystal 2 Change the course in the direction of the force on the surface (Y-axis direction). Note that the structural force of the photonic band, which will be described later, can be obtained as a condition for reflecting in the axial direction.
[0045] さらに、 1次元フォトニック結晶 2の出射側傾斜面 2bで反射して出射光 6となった光 は、 1次元フォトニック結晶 2の底面から出射される。 1次元フォトニック結晶 2からの出 射光 6は、基板 1に入射され、基板 1内を伝播して、基板 1から外部に出射される。基 板 1から出射された出射光 6は、光出力部 4に導かれる。具体的には、基板 1から出 射された出射光 6は、対物レンズ 4c、コリメートレンズ 4bを順次通過して、光ファイバ 4 aに入射する。  Furthermore, the light that is reflected by the exit-side inclined surface 2 b of the one-dimensional photonic crystal 2 and becomes the emitted light 6 is emitted from the bottom surface of the one-dimensional photonic crystal 2. The emitted light 6 from the one-dimensional photonic crystal 2 is incident on the substrate 1, propagates through the substrate 1, and is emitted from the substrate 1 to the outside. The emitted light 6 emitted from the substrate 1 is guided to the light output unit 4. Specifically, the outgoing light 6 emitted from the substrate 1 sequentially passes through the objective lens 4c and the collimating lens 4b and enters the optical fiber 4a.
[0046] 1次元フォトニック結晶 2内を伝播する伝播光 8は、フォトニックバンド構造における ブリルアンゾーン境界上のモードによって伝播するのが望ましぐこれにより、導波路 素子 10を光制御素子として機能させることができる。  [0046] The propagating light 8 propagating in the one-dimensional photonic crystal 2 is desirably propagated by a mode on the Brillouin zone boundary in the photonic band structure, thereby functioning the waveguide element 10 as a light control element. Can be made.
[0047] ブリルアンゾーン境界上のモードによって伝播する伝播光 8は、以下の式を満たす ことにより、 XZ平面方向にぉ ヽては伝播の方向によらずに閉じ込められる。  [0047] The propagating light 8 propagating in the mode on the Brillouin zone boundary is confined in the XZ plane direction regardless of the propagation direction by satisfying the following equation.
[0048] a/ λ < l/ (2n )  [0048] a / λ <l / (2n)
0 S  0 S
ここで、 λ は 1次元フォトニック結晶 2内を伝播する伝播光 8の真空中における波  Where λ is the wave of propagating light 8 propagating in the one-dimensional photonic crystal 2 in vacuum
0  0
長である。また、 aは 1次元フォトニック結晶 2の屈折率周期である。また、 n は 1次元  It is long. A is the refractive index period of the one-dimensional photonic crystal 2. N is one dimension
S  S
フォトニック結晶 2の側面、すなわち、 1次元フォトニック結晶 2の周期構造が露出して V、る面に接して 、る媒体の屈折率であり、本実施の形態では上記したように空気の 屈折率である。尚、 1次元フォトニック結晶 2内における、ブリルアンゾーン境界上の モードによって伝播する伝播光 8の閉じ込め条件については、例えば、国際公開第 0 5Z008305号パンフレット等に詳しく開示されている。  The refractive index of the medium that is in contact with the side surface of the photonic crystal 2, that is, the periodic structure of the one-dimensional photonic crystal 2 and is in contact with the V surface. In this embodiment, as described above, the refraction of air Rate. The confinement condition of the propagating light 8 propagating in the mode on the Brillouin zone boundary in the one-dimensional photonic crystal 2 is disclosed in detail in, for example, International Publication No. 05Z008305 pamphlet.
[0049] 1次元フォトニック結晶 2内の伝播光 8については、フォトニックバンドを計算し、それ を図示することによって知ることができる。尚、フォトニックバンドのバンド計算の方法 は、例えば、「Photonic Crystals, Princeton University Press, (1995)」、あるいは、「Ph ysical Review B, 1991年， 44卷， 16号， p.8565」等に詳しく述べられている。そこで、入 射側傾斜面 2aの傾斜角度 φ 及び出射側傾斜面 2bの傾斜角度 φ は、上記バンド a b [0049] The propagation light 8 in the one-dimensional photonic crystal 2 can be known by calculating a photonic band and illustrating it. For example, the photonic band calculation method is described in “Photonic Crystals, Princeton University Press, (1995)” or “Physical Review B, 1991, 44, No. 16, p.8565”. It is described in detail. Therefore, the inclination angle φ of the incident side inclined surface 2a and the inclination angle φ of the outgoing side inclined surface 2b are determined by the above band a b
計算の結果に基づ 、て選択することができる。  It can be selected based on the result of the calculation.
[0050] 図 3に、本実施の形態の導波路素子における、入射側の光の進路を説明するため の側面図を示す。図 3は、 1次元フォトニック結晶 2の入射側傾斜面 2a付近の構成を 示す拡大側面図であり、図 3においては、光入力部は省略されている。図 3に示すよ うに、光入力部（図示せず)からの光 (入射光 5)が基板 1を透過して、 1次元フォト-ッ ク結晶 2内に入射されると、 1次元フォトニック結晶 2の外部に 2種類の屈折光 7a、 7b が漏れる。これら屈折光 7a、 7b以外の光は、入射側傾斜面 2aで反射して、 Z軸方向 に進行する伝播光 8となる。 [0050] FIG. 3 illustrates the path of light on the incident side in the waveguide element of the present embodiment. The side view of is shown. FIG. 3 is an enlarged side view showing a configuration in the vicinity of the incident-side inclined surface 2a of the one-dimensional photonic crystal 2. In FIG. 3, the light input portion is omitted. As shown in FIG. 3, when light (incident light 5) from a light input section (not shown) passes through the substrate 1 and enters the one-dimensional photonic crystal 2, it is one-dimensional photonic. Two types of refracted light 7a and 7b leak outside the crystal 2. The light other than the refracted lights 7a and 7b is reflected by the incident side inclined surface 2a and becomes propagating light 8 that travels in the Z-axis direction.
[0051] 図 4に、図 3に対応するバンド図を示す。図 4は、コアである 1次元フォトニック結晶 2 、入射光 5の入射側の媒体である基板 1、入射側傾斜面 2aに接している媒体 (本実 施の形態では空気）のそれぞれのフォトニックバンド構造を、 YZ平面の逆空間に図 示したものである。以下、図 3を参照しながら、図 4のバンド図について説明する。  FIG. 4 shows a band diagram corresponding to FIG. Figure 4 shows the photo of each of the one-dimensional photonic crystal 2 that is the core, the substrate 1 that is the medium on the incident side of the incident light 5, and the medium that is in contact with the incident side inclined surface 2a (air in this embodiment). The nick band structure is illustrated in the inverse space of the YZ plane. Hereinafter, the band diagram of FIG. 4 will be described with reference to FIG.
[0052] 1次元フォトニック結晶 2のバンドは周期性を示すため、図 4に示すように、当該 1次 元フォトニック結晶 2のバンドは周期的ゾーン方式で示されており、この周波数におい ては、第 1バンドと第 2バンドとが存在している。破線 11は、基板 1と 1次元フォトニック 結晶 2との境界を表わし、破線 12は、空気と 1次元フォトニック結晶 2との境界 (入射 側傾斜面 2aに対応）を表わして 、る。  [0052] Since the band of the one-dimensional photonic crystal 2 shows periodicity, as shown in FIG. 4, the band of the one-dimensional photonic crystal 2 is shown by a periodic zone method, and at this frequency. There are a first band and a second band. The broken line 11 represents the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and the broken line 12 represents the boundary between the air and the one-dimensional photonic crystal 2 (corresponding to the incident side inclined surface 2a).
[0053] 基板 1と空気は、屈折率が一様な均質媒体であり、図 4に示すように、それらを示す バンドは単純な円となる。基板 1のバンドの中心点は、基板 1と 1次元フォトニック結晶 2との境界を表わす破線 11の法線であって、 1次元フォトニック結晶 2の中心点を通 る線上に位置する。また、空気のバンドの中心点は、空気と 1次元フォトニック結晶 2と の境界を表わす破線 12の法線であって、 1次元フォトニック結晶 2の中心点を通る線 上に位置する。また、図 4中に示した矢印は、バンド上の各結合点 A〜Gにおけるェ ネルギ一の進行方向を示し、このエネルギーの進行方向はバンドの法線方向となる  The substrate 1 and air are homogeneous media having a uniform refractive index, and as shown in FIG. 4, the bands indicating them are simple circles. The center point of the band of the substrate 1 is a normal line of the broken line 11 representing the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2. The center point of the air band is the normal line of the broken line 12 representing the boundary between air and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2. In addition, the arrows shown in FIG. 4 indicate the energy traveling direction at each of the coupling points A to G on the band, and the energy traveling direction is the normal direction of the band.
[0054] 図 4において、基板 1側力も入射した入射光 5は、 1次元フォトニック結晶 2の第 2バ ンド上の結合点 Aによる光と結合する。次に、空気と 1次元フォトニック結晶 2との境界 を表わす破線 12と直交し、結合点 Aと交わる線 13と、各バンドとの交点での光が、結 合点 Aによる Y軸方向の伝播光と結合する。ここで、 1次元フォトニック結晶 2内に入 射する入射光 5とブリルアンゾーン境界上の伝播モードとは、入射側傾斜面 2aに対 応する破線 12の同じ法線上に存在するように選ばれる。つまり、破線 12と直交する 線 13上に、入射光 5のモードを示す結合点 A及び伝播光 8のモードを示す結合点 B とが存在する。 In FIG. 4, the incident light 5 on which the substrate 1 side force has also entered is coupled with light from the coupling point A on the second band of the one-dimensional photonic crystal 2. Next, light at the intersection of the line 13 perpendicular to the broken line 12 representing the boundary between the air and the one-dimensional photonic crystal 2 and intersecting the coupling point A and each band propagates in the Y-axis direction at the coupling point A. Combine with light. Here, the incident light 5 incident on the one-dimensional photonic crystal 2 and the propagation mode on the Brillouin zone boundary correspond to the incident-side inclined surface 2a. It is chosen to lie on the same normal of the corresponding dashed line 12. That is, the coupling point A indicating the mode of the incident light 5 and the coupling point B indicating the mode of the propagating light 8 exist on the line 13 orthogonal to the broken line 12.
[0055] 尚、結合点 Aは複数存在しているが、これらはすべて周期性に基づく等価な点であ る。また、結合点 A以外の結合点 B〜Gについても同様であり、同一の符号で示され る結合点は等価な点を表わして 、る。  [0055] Although there are a plurality of coupling points A, these are all equivalent points based on periodicity. The same applies to the connection points B to G other than the connection point A, and the connection points indicated by the same reference numerals represent equivalent points.
[0056] 基板 1側から 1次元フォトニック結晶 2内に入射してきた光である結合点 Aによる光 は、入射側傾斜面 2aで反射して、第 1バンドのブリルアンゾーン境界上の結合点 Bの 光と結合する。但し、基板 1側から 1次元フォトニック結晶 2内に入射してきた光である 結合点 Aによる光は、入射側傾斜面 2aで反射した場合に、結合点 Cの光と結合する 可能性もある。また、基板 1側から 1次元フォトニック結晶 2内に入射してきた光である 結合点 Aによる光は、入射側傾斜面 2aで反射した場合に、結合点 D及び結合点 Eの 光と結合する可能性もあるが、これらは、矢印から分力るように、入射側傾斜面 2aへ と再び進行するので、無視することができる。従って、入射側傾斜面 2aで反射される 光は、結合点 B及び結合点 Cの光のみである。  [0056] The light from the coupling point A that is incident on the one-dimensional photonic crystal 2 from the substrate 1 side is reflected by the incident-side inclined surface 2a, and the coupling point B on the Brillouin zone boundary of the first band. Combine with the light. However, the light incident on the one-dimensional photonic crystal 2 from the substrate 1 side and the light from the coupling point A may be combined with the light at the coupling point C when reflected by the incident side inclined surface 2a. . In addition, the light from the coupling point A, which is the light incident on the one-dimensional photonic crystal 2 from the substrate 1 side, is combined with the light at the coupling point D and the coupling point E when reflected by the incident side inclined surface 2a. Although there is a possibility, since they proceed again to the incident side inclined surface 2a as a force component from the arrow, they can be ignored. Therefore, the light reflected by the incident side inclined surface 2a is only the light at the coupling point B and the coupling point C.
[0057] また、結合点 Aを通り、破線 12に垂直な線 13は、空気のバンドと結合点 F及び結合 点 Gで交わるので、それぞれの結合点 F及び結合点 Gの矢印で示した方向の屈折光 7a、 7bが空気側に発生する。  [0057] In addition, a line 13 that passes through the coupling point A and is perpendicular to the broken line 12 intersects the air band at the coupling point F and the coupling point G. Therefore, the directions indicated by the arrows of the coupling point F and the coupling point G respectively. Refracted lights 7a and 7b are generated on the air side.
[0058] つまり、図 4に示した光は、以下に示すとおりである。結合点 Aでの光は、基板 1側 力 1次元フォトニック結晶 2内に入射してきた入射光 5と同じ向きの伝播光である。 結合点 B及び結合点 Cでの光は、入射側傾斜面 2aでの反射によって生じた 1次元フ オトニック結晶 2内の伝播光である。また、結合点 F及び結合点 Gでの光は、入射側 傾斜面 2aから外部に漏れる屈折光 7a、 7bである。尚、図 3には図示していないが、 結合点 Cでの光は、 1次元フォトニック結晶 2から基板 1側へ向力 反射戻り光となる 可能性がある。  That is, the light shown in FIG. 4 is as shown below. The light at the coupling point A is propagating light in the same direction as the incident light 5 incident on the substrate 1 side force one-dimensional photonic crystal 2. The light at the coupling point B and the coupling point C is propagating light in the one-dimensional photonic crystal 2 generated by reflection on the incident side inclined surface 2a. The light at the coupling point F and the coupling point G is refracted light 7a and 7b that leaks to the outside from the incident side inclined surface 2a. Although not shown in FIG. 3, the light at the coupling point C may be reflected back from the one-dimensional photonic crystal 2 toward the substrate 1 side.
[0059] 次に、出射側傾斜面 2b付近での光の進路について説明する。  Next, the light path in the vicinity of the exit-side inclined surface 2b will be described.
[0060] 図 5に、本実施の形態の導波路素子における、出射側の光の進路を説明するため の側面図を示す。図 5は、 1次元フォトニック結晶 2の出射側傾斜面 2b付近の構成を 示す拡大側面図であり、図 5においては、光出力部は省略されている。図 5に示すよ うに、 1次元フォトニック結晶 2内の伝播光 8は、出射側傾斜面 2bで反射して、 1次元 フォトニック結晶 2の底面側（基板 1側）へと進路が変更される。 1次元フォトニック結晶 2の底面から出射された出射光 6は、基板 1を透過して光出力部（図示せず）に導か れる。尚、出射側傾斜面 2bにおいて、 1次元フォトニック結晶 2の外部に 2種類の屈 折光 9a、 9bが漏れる。 FIG. 5 is a side view for explaining the path of light on the emission side in the waveguide element of the present embodiment. Figure 5 shows the configuration of the exit side inclined surface 2b of the one-dimensional photonic crystal 2. FIG. 5 is an enlarged side view, and the light output unit is omitted in FIG. As shown in Fig. 5, the propagation light 8 in the one-dimensional photonic crystal 2 is reflected by the outgoing inclined surface 2b, and the path is changed to the bottom surface side (substrate 1 side) of the one-dimensional photonic crystal 2. The Outgoing light 6 emitted from the bottom surface of the one-dimensional photonic crystal 2 passes through the substrate 1 and is guided to a light output unit (not shown). Note that two kinds of bending lights 9a and 9b leak to the outside of the one-dimensional photonic crystal 2 on the exit side inclined surface 2b.
[0061] 図 6に、図 5に対応するバンド図を示す。図 6は、コアである 1次元フォトニック結晶 2 、出射光 6の出射側の媒体である基板 1、出射側傾斜面 2bに接している媒体 (本実 施の形態では空気）のそれぞれのフォトニックバンド構造を、 YZ平面の逆空間に図 示したものである。以下、図 5を参照しながら、図 6のバンド図について説明する。  FIG. 6 shows a band diagram corresponding to FIG. Fig. 6 shows the photo of the one-dimensional photonic crystal 2 that is the core, the substrate 1 that is the medium on the output side of the output light 6, and the medium (air in this embodiment) that is in contact with the output-side inclined surface 2b. The nick band structure is illustrated in the inverse space of the YZ plane. Hereinafter, the band diagram of FIG. 6 will be described with reference to FIG.
[0062] 1次元フォトニック結晶 2のバンドは周期性を示すため、図 6に示すように、当該 1次 元フォトニック結晶 2のバンドは周期的ゾーン方式で示されており、この周波数におい ては、第 1バンドと第 2バンドとが存在している。破線 16は、基板 1と 1次元フォトニック 結晶 2との境界を表わし、破線 17は、空気と 1次元フォト ック結晶 2との境界（出射 側傾斜面 2bに対応）を表わして 、る。  [0062] Since the band of the one-dimensional photonic crystal 2 shows periodicity, as shown in Fig. 6, the band of the one-dimensional photonic crystal 2 is shown by a periodic zone method, and at this frequency. The first band and the second band exist. The broken line 16 represents the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and the broken line 17 represents the boundary between air and the one-dimensional photonic crystal 2 (corresponding to the outgoing side inclined surface 2b).
[0063] 基板 1と空気は、屈折率が一様な均質媒体であり、図 6に示すように、それらを示す バンドは単純な円となる。基板 1のバンドの中心点は、基板 1と 1次元フォトニック結晶 2との境界を表わす破線 16の法線であって、 1次元フォトニック結晶 2の中心点を通 る線上に位置する。また、空気のバンドの中心点は、空気と 1次元フォトニック結晶 2と の境界を表わす破線 17の法線であって、 1次元フォトニック結晶 2の中心点を通る線 上に位置する。また、図 6中に示した矢印は、バンド上の各結合点 H〜Mにおけるェ ネルギ一の進行方向を示し、このエネルギーの進行方向はバンドの法線方向となる 。尚、例えば結合点 Hは複数存在しているが、これらはすべて周期性に基づく等価な 点である。また、結合点 H以外の結合点 I〜Mについても同様であり、同一の符号で 示される結合点は等価な点を表わしている。図 6において、空気と 1次元フォトニック 結晶 2との境界を表わす破線 17と直交し、結合点 Hと交わる線 18と、各バンドとの交 点での光が、伝播光 8と結合する光である。  [0063] The substrate 1 and air are homogeneous media having a uniform refractive index, and as shown in Fig. 6, the bands indicating them are simple circles. The center point of the band of the substrate 1 is a normal line of the broken line 16 representing the boundary between the substrate 1 and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2. The center point of the air band is the normal line of the broken line 17 representing the boundary between air and the one-dimensional photonic crystal 2, and is located on the line passing through the center point of the one-dimensional photonic crystal 2. Also, the arrows shown in FIG. 6 indicate the energy traveling directions at each of the coupling points H to M on the band, and the energy traveling direction is the normal direction of the band. For example, there are a plurality of coupling points H, but these are all equivalent points based on periodicity. The same applies to the connection points I to M other than the connection point H, and the connection points indicated by the same reference numerals represent equivalent points. In FIG. 6, the light that is orthogonal to the broken line 17 representing the boundary between the air and the one-dimensional photonic crystal 2 and intersects the coupling point H and the light at the intersection of each band is the light that couples with the propagating light 8. It is.
[0064] ブリルアンゾーン境界上の伝播光 8である結合点 Hでの光は、出射側傾斜面 2bで 反射して、結合点 Iの光と結合し、そのまま 1次元フォトニック結晶 2の底面力 垂直に 外部へ出射する出射光 6となる。但し、伝播光 8は、出射側傾斜面 2bで反射した場 合に、結合点 Jの光と結合する可能性もある。また、伝播光 8は、出射側傾斜面 2bで 反射した場合に、結合点 Kの光と結合する可能性もある力 これは、矢印から分かる ように、出射側傾斜面 2bへと再び進行するので、無視することができる。従って、出 射側傾斜面 2bで反射される光は、結合点 I及び結合点 Jの光のみである。 [0064] The light at the coupling point H, which is the propagating light 8 on the Brillouin zone boundary, passes through the outgoing inclined surface 2b. The light is reflected and combined with the light at the coupling point I, and becomes the outgoing light 6 that is directly emitted to the outside perpendicularly to the bottom force of the one-dimensional photonic crystal 2. However, there is a possibility that the propagating light 8 is coupled with the light at the coupling point J when reflected by the outgoing side inclined surface 2b. In addition, if the propagating light 8 is reflected by the exit-side inclined surface 2b, there is a possibility that the propagating light 8 may be combined with the light at the coupling point K. So it can be ignored. Therefore, the light reflected by the emission side inclined surface 2b is only the light at the coupling point I and the coupling point J.
[0065] また、結合点 Hを通り、破線 17に垂直な線 18は、空気のバンドと結合点 L及び結合 点 Mで交わるので、それぞれの結合点 L及び結合点 Mの矢印で示した方向の屈折 光 9a、 9bが空気側に発生する。  [0065] Since the line 18 passing through the coupling point H and perpendicular to the broken line 17 intersects the air band at the coupling point L and the coupling point M, the directions indicated by the arrows of the coupling point L and the coupling point M respectively. Refraction light 9a, 9b is generated on the air side.
[0066] つまり、図 6に示した光は、以下に示すとおりである。結合点 Hでの光は、 1次元フォ トニック結晶 2内の伝播光 8である。また、結合点 Iでの光は、出射側傾斜面 2bで反射 して基板 1側へ向かう出射光 6である。また、結合点 L及び結合点 Mでの光は、出射 側傾斜面 2bから外部に漏れる屈折光 9a、 9bである。尚、図 5には図示していないが 、結合点 Jでの光は、 1次元フォトニック結晶 2から基板 1側へ向かう出射光となる可能 性がある。結合点 Jでの光は、結合点 Iでの光と進行方向が異なる。  That is, the light shown in FIG. 6 is as shown below. Light at the coupling point H is propagating light 8 in the one-dimensional photonic crystal 2. The light at the coupling point I is outgoing light 6 that is reflected by the outgoing side inclined surface 2b and travels toward the substrate 1 side. The light at the coupling point L and the coupling point M is refracted light 9a and 9b that leaks to the outside from the exit-side inclined surface 2b. Although not shown in FIG. 5, the light at the coupling point J may be emitted from the one-dimensional photonic crystal 2 toward the substrate 1 side. The light at the junction point J travels differently from the light at the junction point I.
[0067] 図 4及び図 6に示した光のうち、本実施の形態の導波路素子 10で用いられるのは、 結合点 Aでの光 (入射光 5)、結合点 Bでの光 (伝播光 8)、結合点 Hでの光 (伝播光 8 )及び結合点 Iでの光（出射光 6)である。  [0067] Of the light shown in FIGS. 4 and 6, the waveguide element 10 of the present embodiment uses light at the coupling point A (incident light 5) and light at the coupling point B (propagation). Light 8), light at coupling point H (propagating light 8) and light at coupling point I (emitted light 6).
[0068] 図 4の結合点 Cでの光及び図 6の結合点 Jでの光は、小さ 、のが望まし 、。そこで、 例えば 1次元フォトニック結晶 2の第 2バンドを示す楕円の径が小さくなる周波数域に おいて、傾斜角度 φ a及び傾斜角度 φ の  [0068] It is desirable that the light at the coupling point C in FIG. 4 and the light at the coupling point J in FIG. 6 be small. Therefore, for example, in the frequency region where the diameter of the ellipse indicating the second band of the one-dimensional photonic crystal 2 becomes small, the inclination angle φ a and the inclination angle φ are
b 設計を行えばよい。これにより、結合点 Jで の光を存在させないようにすることも可能である。そして、これにより、出射側傾斜面 2 bでの反射光を結合点 Iの光とのみ結合させることが可能となる。  b Design should be done. As a result, it is possible to prevent the light at the coupling point J from existing. As a result, it is possible to couple the reflected light on the exit side inclined surface 2 b only with the light at the coupling point I.
[0069] 本実施の形態の導波路素子 10においては、入射側傾斜面 2a及び出射側傾斜面 2bに反射層を形成するようにしてもよい。図 7に、本実施の形態における反射層を備 えた導波路素子の構成を示す。尚、図 7において、図 1、図 2に示す部材と同様の機 能を有する部材には同一の参照符号を付し、それらの説明は省略する。  [0069] In the waveguide element 10 of the present embodiment, a reflective layer may be formed on the incident side inclined surface 2a and the emission side inclined surface 2b. FIG. 7 shows the configuration of a waveguide element provided with a reflective layer in this embodiment. In FIG. 7, members having the same functions as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.
[0070] 図 7において、図 1、図 2と異なる点は、入射側傾斜面 2a及び出射側傾斜面 2bにそ れぞれ反射層 21a及び反射層 21bが形成されている点である。このように反射層 21a 及び反射層 21bを形成することにより、結合点 F、結合点 G、結合点 L及び結合点 M での光（屈折光 7a、 7b、 9a、 9b) (図 3〜図 6参照）が、 1次元フォトニック結晶 2の外 部に漏れず、そのエネルギーが伝播光 8及び出射光 6のエネルギーとなる。その結 果、光の損失を減少させて、結合効率を大きくすることができる。 FIG. 7 differs from FIG. 1 and FIG. 2 in that the incident side inclined surface 2a and the emission side inclined surface 2b are different from each other. The point is that the reflective layer 21a and the reflective layer 21b are formed. By forming the reflective layer 21a and the reflective layer 21b in this way, light at the coupling point F, the coupling point G, the coupling point L, and the coupling point M (refracted light 7a, 7b, 9a, 9b) (Figs. However, it does not leak to the outside of the one-dimensional photonic crystal 2 and its energy becomes the energy of propagating light 8 and outgoing light 6. As a result, the light loss can be reduced and the coupling efficiency can be increased.
[0071] 反射層 21a及び反射層 21bとしては、例えば、金属膜を用いればよい。銀、アルミ ユウム、金といった材料は、反射率が高ぐ成膜も容易であることから、反射層 21a及 び反射層 21bの材料として特に望ましい。金属膜は、例えば、真空蒸着法ゃスパッタ リング法等によって容易に成膜することができる。また、反射層 21a及び反射層 21bと しては、金属膜以外に、誘電体多層膜を用いてもよい。誘電体多層膜の材料として は、一般に薄膜の材料として用いられ、耐久性や成膜コストの点で優れた、シリカ、シ リコン、酸化チタン、酸化タンタル、酸化ニオブ、フッ化マグネシウム及び窒化シリコン 等といった材料を用いればよい。これらの材料は、スパッタリング法、真空蒸着法、ィ オンアシスト蒸着法又はプラズマ CVD法等により、容易に薄膜とすることができる。 [0071] As the reflective layer 21a and the reflective layer 21b, for example, a metal film may be used. A material such as silver, aluminum, or gold is particularly desirable as a material for the reflective layer 21a and the reflective layer 21b because it has high reflectivity and can be easily formed. The metal film can be easily formed by, for example, a vacuum deposition method or a sputtering method. In addition to the metal film, a dielectric multilayer film may be used as the reflective layer 21a and the reflective layer 21b. As a material for the dielectric multilayer film, silica, silicon, titanium oxide, tantalum oxide, niobium oxide, magnesium fluoride, silicon nitride, etc., which are generally used as thin film materials and are excellent in terms of durability and film formation cost, etc. Such a material may be used. These materials can be easily formed into thin films by sputtering, vacuum deposition, ion-assisted deposition, plasma CVD, or the like.
[0072] 以上説明した本実施の形態の導波路素子 10において、入射光 5及び出射光 6の 進行方向は伝播光 8の進行方向に対して略垂直な方向である。従って、本実施の形 態の導波路素子 10を用いることにより、垂直結合に適した光回路を実現することがで きる。また、複数の周波数の光の入射、伝播、出射が可能となる。また、本実施の形 態の導波路素子 10は、フォトニックバンド構造におけるブリルアンゾーン境界上のモ ードによって伝播する伝播光を用いていることから、光制御素子として機能させること もできる。さらに、本実施の形態の導波路素子 10は、 1次元フォトニック結晶 2を用い ていることから、構成が簡単であるために容易に作製することができ、小型化が可能 な導波路素子を実現することができる。  In the waveguide element 10 of the present embodiment described above, the traveling directions of the incident light 5 and the outgoing light 6 are substantially perpendicular to the traveling direction of the propagating light 8. Therefore, by using the waveguide element 10 of the present embodiment, an optical circuit suitable for vertical coupling can be realized. In addition, light having a plurality of frequencies can be incident, propagated, and emitted. In addition, the waveguide element 10 of the present embodiment can function as a light control element because it uses propagating light that propagates in a mode on the Brillouin zone boundary in the photonic band structure. Furthermore, since the waveguide element 10 of the present embodiment uses the one-dimensional photonic crystal 2, the waveguide element 10 can be easily manufactured because of its simple configuration, and a waveguide element that can be miniaturized can be obtained. Can be realized.
[0073] [実施の形態 2]  [0073] [Embodiment 2]
本発明の実施の形態 2における導波路素子について、図を参照しながら説明する 。図 8は、本発明の実施の形態 2における導波路素子の構成を示す側面図である。 尚、図 8において、図 2に示す部材と同様の機能を有する部材には同一の参照符号 を付し、それらの説明は省略する。 [0074] 図 8に示すように、本実施の形態の導波路素子 10aにおいては、上記実施の形態 1 の導波路素子 10の場合と同様に、光入力部 3からの光 (入射光 5)が、基板 1を介し て、 1次元フォトニック結晶 2内にその底面力も入射される。そして、当該入射光 5は、 入射側傾斜面 2aで反射して伝播光 8となり、 1次元フォトニック結晶 2内を伝播する。 しかし、上記実施の形態 1の導波路素子 10の場合とは異なり、伝播光 8は、出射側 傾斜面 2bで反射せずに当該出射側傾斜面 2bを通って出射される。つまり、図 8に示 す導波路素子 10aにおいて、入射光 5は基板 1を介して 1次元フォトニック結晶 2内に 入射されるが、出射光 6aは出射側傾斜面 2bから直接出射される。 A waveguide element according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a side view showing the configuration of the waveguide element according to the second embodiment of the present invention. In FIG. 8, members having the same functions as those shown in FIG. 2 are given the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 8, in the waveguide element 10a of the present embodiment, light from the light input unit 3 (incident light 5) is the same as in the case of the waveguide element 10 of the first embodiment. However, the bottom force also enters the one-dimensional photonic crystal 2 through the substrate 1. Then, the incident light 5 is reflected by the incident side inclined surface 2 a to become the propagation light 8 and propagates in the one-dimensional photonic crystal 2. However, unlike the case of the waveguide element 10 of the first embodiment, the propagating light 8 is emitted through the emission side inclined surface 2b without being reflected by the emission side inclined surface 2b. That is, in the waveguide element 10a shown in FIG. 8, the incident light 5 enters the one-dimensional photonic crystal 2 through the substrate 1, but the emitted light 6a is directly emitted from the emission-side inclined surface 2b.
[0075] 導波路素子 10aにおいては、上記したように、伝播光 8が出射側傾斜面 2bから出 射光 6aとして出射される。そのため、出射光 6aが導かれる光出力部 14は、出射側傾 斜面 2bに面して配置されている。光出力部 14は、光ファイバ 14aとコリメータレンズ 1 4bと対物レンズ 14cとを備えて 、る。  In the waveguide element 10a, as described above, the propagation light 8 is emitted as the emission light 6a from the emission side inclined surface 2b. For this reason, the light output part 14 to which the outgoing light 6a is guided is arranged facing the outgoing side inclined surface 2b. The light output unit 14 includes an optical fiber 14a, a collimator lens 14b, and an objective lens 14c.
[0076] 次に、本実施の形態の導波路素子 10aの動作について説明する。  [0076] Next, the operation of the waveguide element 10a of the present embodiment will be described.
[0077] まず、光ファイバ 3aを伝播してきた入射光 5は、コリメータレンズ 3bで平行光とされ た後、対物レンズ 3cで集光されて、基板 1に入射される。光入力部 3からの光 (入射 光 5)は、基板 1内を伝播した後、 1次元フォトニック結晶 2内に、 1次元フォトニック結 晶 2の底面から入射される。 1次元フォトニック結晶 2内を伝播した入射光 5は、入射 側傾斜面 2aに到達して Z軸方向に反射し、 1次元フォトニック結晶 2内を Z軸方向に 伝播する。尚、 1次元フォトニック結晶 2内を伝播する伝播光 8は、フォトニックバンド 構造におけるブリルアンゾーン境界上のモードによって伝播するのが望ましい。また 、入射側傾斜面 2aには、例えば、金属膜や誘電体多層膜等からなる反射層を設け てもよい。  First, the incident light 5 that has propagated through the optical fiber 3 a is converted into parallel light by the collimator lens 3 b, condensed by the objective lens 3 c, and incident on the substrate 1. Light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the one-dimensional photonic crystal 2 from the bottom surface of the one-dimensional photonic crystal 2. Incident light 5 propagated in the one-dimensional photonic crystal 2 reaches the incident-side inclined surface 2a, is reflected in the Z-axis direction, and propagates in the one-dimensional photonic crystal 2 in the Z-axis direction. The propagating light 8 propagating in the one-dimensional photonic crystal 2 is preferably propagated by a mode on the Brillouin zone boundary in the photonic band structure. The incident side inclined surface 2a may be provided with a reflective layer made of, for example, a metal film or a dielectric multilayer film.
[0078] 1次元フォトニック結晶 2内を Z軸方向に伝播している伝播光 8は、出射側傾斜面 2b に到達する。そして、伝播光 8は、出射側傾斜面 2bから出射光 6aとして出射される。 1次元フォトニック結晶 2の出射側傾斜面 2bから出射された出射光 6aは、光出力部 1 4に導かれる。具体的には、 1次元フォト ック結晶 2の出射側傾斜面 2bから出射さ れた出射光 6aは、対物レンズ 14c、コリメートレンズ 14bを順次通過して、光ファイバ 1 4aに入射する。 [0079] 本実施の形態の導波路素子 10aは、上記実施の形態 1の導波路素子 10と同様の 効果を奏することができる。 [0078] The propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b. The propagating light 8 is emitted as outgoing light 6a from the outgoing side inclined surface 2b. The outgoing light 6 a emitted from the outgoing side inclined surface 2 b of the one-dimensional photonic crystal 2 is guided to the light output unit 14. Specifically, the outgoing light 6a emitted from the outgoing side inclined surface 2b of the one-dimensional photonic crystal 2 sequentially passes through the objective lens 14c and the collimating lens 14b and enters the optical fiber 14a. [0079] The waveguide element 10a of the present embodiment can achieve the same effects as the waveguide element 10 of the first embodiment.
[0080] 1次元フォトニック結晶 2は、出射側傾斜面 2bを備えていなくてもよい。 1次元フォト ニック結晶 2の出射側の端面が垂直端面であっても、例えば、当該端面に位相格子 を設けること等により、ブリルアンゾーン境界上のモードによって伝播する伝播光 8を 光出力部 14に導くことができる。また、出射光 6を取り出す必要がないような導波路 素子の場合には、光出力部 14を設ける必要もない。例えば、制御光あるいは励起光 として用いるために入射光 5を入射させる導波路素子の場合には、伝播光 8のェネル ギ一の減衰が著しいことがある。そのような場合には、出射光 6を取り出す必要がない ので、光出力部 14を設ける必要がない。  [0080] The one-dimensional photonic crystal 2 may not include the exit-side inclined surface 2b. Even if the end face on the exit side of the one-dimensional photonic crystal 2 is a vertical end face, for example, by providing a phase grating on the end face, the propagating light 8 propagating in the mode on the Brillouin zone boundary is transmitted to the light output section 14. Can lead. Further, in the case of a waveguide element in which it is not necessary to take out the emitted light 6, it is not necessary to provide the light output unit 14. For example, in the case of a waveguide element in which incident light 5 is incident for use as control light or excitation light, the attenuation of energy of propagating light 8 may be significant. In such a case, it is not necessary to take out the emitted light 6, and therefore it is not necessary to provide the light output unit 14.
[0081] 尚、本実施の形態の導波路素子 10aにおける各条件は、バンド計算によって求め ればよい。  [0081] Each condition in the waveguide element 10a of the present embodiment may be obtained by band calculation.
[0082] [実施の形態 3]  [Third Embodiment]
本発明の実施の形態 3における導波路素子について、図を参照しながら説明する 。図 9は、本発明の実施の形態 3における導波路素子の構成を示す側面図である。 尚、図 9において、図 2に示す部材と同様の機能を有する部材には同一の参照符号 を付し、それらの説明は省略する。  A waveguide element according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 9 is a side view showing the configuration of the waveguide element according to Embodiment 3 of the present invention. In FIG. 9, members having the same functions as those shown in FIG. 2 are given the same reference numerals, and descriptions thereof are omitted.
[0083] 図 9に示すように、本実施の形態の導波路素子 10bにおいては、上記実施の形態 1の導波路素子 10の場合と同様に、伝播光 8が、出射側傾斜面 2bで反射し、基板 1 を介して出射光 6として出射される。しかし、上記実施の形態 1の導波路素子 10の場 合とは異なり、入射光 5aは、基板 1を介さずに直接、入射側傾斜面 2aから 1次元フォ トニック結晶 2内に入射される。入射側傾斜面 2aから 1次元フォトニック結晶 2内に入 射された入射光 5aは、伝播光 8となって 1次元フォトニック結晶 2内を伝播する。つま り、図 9に示す導波路素子 10bにおいて、入射光 5aは入射側傾斜面 2aから直接 1次 元フォトニック結晶 2内に入射される力 出射光 6は基板 1を介して出射される。  As shown in FIG. 9, in the waveguide element 10b of the present embodiment, as in the case of the waveguide element 10 of the first embodiment, the propagating light 8 is reflected by the emission side inclined surface 2b. Then, it is emitted as outgoing light 6 through the substrate 1. However, unlike the case of the waveguide element 10 of the first embodiment, the incident light 5a is directly incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2a without passing through the substrate 1. Incident light 5 a incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2 a becomes propagating light 8 and propagates in the one-dimensional photonic crystal 2. In other words, in the waveguide element 10b shown in FIG. 9, the incident light 5a is emitted from the incident side inclined surface 2a directly into the one-dimensional photonic crystal 2 and the force-emitted light 6 is emitted through the substrate 1.
[0084] 導波路素子 10bにおいては、上記したように、入射光 5aが、基板 1を介さずに直接 、入射側傾斜面 2aから 1次元フォトニック結晶 2内に入射される。そのため、入射光 5 aを 1次元フォトニック結晶 2内に入射させる光入力部 19は、入射側傾斜面 2aに面し て配置されている。光入力部 19は、光ファイバ 19aとコリメータレンズ 19bと対物レン ズ 19cとを備えている。 In the waveguide element 10b, as described above, the incident light 5a is directly incident on the one-dimensional photonic crystal 2 from the incident side inclined surface 2a without passing through the substrate 1. For this reason, the light input section 19 for making the incident light 5 a incident on the one-dimensional photonic crystal 2 faces the incident-side inclined surface 2 a. Are arranged. The light input unit 19 includes an optical fiber 19a, a collimator lens 19b, and an objective lens 19c.
[0085] 次に、本実施の形態の導波路素子 10bの動作について説明する。  Next, the operation of the waveguide element 10b according to the present embodiment will be described.
[0086] まず、光ファイバ 19aを伝播してきた入射光 5aは、コリメータレンズ 19bで平行光とさ れた後、対物レンズ 19cで集光されて、入射側傾斜面 2aからフォトニック結晶 2内に 入射される。伝播光 8は、 1次元フォトニック結晶 2内を Z軸方向に伝播する。尚、 1次 元フォトニック結晶 2内を伝播する伝播光 8は、フォトニックバンド構造におけるブリル アンゾーン境界上のモードによって伝播するのが望ましい。  First, the incident light 5a propagating through the optical fiber 19a is collimated by the collimator lens 19b, then condensed by the objective lens 19c, and enters the photonic crystal 2 from the incident side inclined surface 2a. Incident. The propagating light 8 propagates through the one-dimensional photonic crystal 2 in the Z-axis direction. The propagating light 8 propagating in the one-dimensional photonic crystal 2 is preferably propagated by a mode on the Brillouin zone boundary in the photonic band structure.
[0087] 1次元フォトニック結晶 2内を Z軸方向に伝播している伝播光 8は、出射側傾斜面 2b に到達する。伝播光 8は、出射側傾斜面 2bで反射して、 1次元フォトニック結晶 2の底 面に向力 方向（Y軸方向）へ進路を変更する。尚、出射側傾斜面 2bには、例えば、 金属膜や誘電体多層膜等カゝらなる反射層を設けてもよい。  [0087] The propagating light 8 propagating through the one-dimensional photonic crystal 2 in the Z-axis direction reaches the exit-side inclined surface 2b. The propagating light 8 is reflected by the outgoing inclined surface 2b and changes its course in the direction of the direction of force (Y-axis direction) on the bottom surface of the one-dimensional photonic crystal 2. Note that a reflective layer such as a metal film or a dielectric multilayer film may be provided on the outgoing side inclined surface 2b.
[0088] さらに、 1次元フォトニック結晶 2の出射側傾斜面 2bで反射して出射光 6となった光 は、 1次元フォトニック結晶 2の底面から出射される。 1次元フォトニック結晶 2からの出 射光 6は、基板 1に入射され、基板 1内を伝播して、基板 1から外部に出射される。基 板 1から出射された出射光 6は、光出力部 4に導かれる。具体的には、基板 1から出 射された出射光 6は、対物レンズ 4c、コリメートレンズ 4bを順次通過して、光ファイバ 4 aに入射する。光出力部 4は、出射光 6が基板 1を介して光出力部 4に導かれるように 配置されている。  [0088] Further, the light that is reflected by the outgoing side inclined surface 2b of the one-dimensional photonic crystal 2 and becomes the outgoing light 6 is emitted from the bottom surface of the one-dimensional photonic crystal 2. The emitted light 6 from the one-dimensional photonic crystal 2 is incident on the substrate 1, propagates through the substrate 1, and is emitted from the substrate 1 to the outside. The emitted light 6 emitted from the substrate 1 is guided to the light output unit 4. Specifically, the outgoing light 6 emitted from the substrate 1 sequentially passes through the objective lens 4c and the collimating lens 4b and enters the optical fiber 4a. The light output unit 4 is arranged so that the emitted light 6 is guided to the light output unit 4 through the substrate 1.
[0089] 本実施の形態の導波路素子 10bは、上記実施の形態 1の導波路素子 10と同様の 効果を奏することができる。  The waveguide element 10b according to the present embodiment can achieve the same effects as the waveguide element 10 according to the first embodiment.
[0090] 1次元フォトニック結晶 2は、入射側傾斜面 2aを備えていなくてもよい。 1次元フォト ニック結晶 2の入射側の端面が垂直端面であっても、伝播光 8を、ブリルアンゾーン 境界上のモードによって伝播する伝播光とすることができる。例えば、 1次元フォト- ック結晶 2の入射側の端面に位相格子を設けて、入射光 5aが位相格子を介して 1次 元フォトニック結晶 2内に入射されるようにすればよい。また、入射光を入射させる必 要がないような導波路素子の場合には、光入力部 19を設ける必要もない。例えば、 外部エネルギーによって発生させたレーザ発振光を伝播光 8として用いる導波路素 子の場合には、光入力部 19を設ける必要がない。 [0090] The one-dimensional photonic crystal 2 may not include the incident-side inclined surface 2a. Even if the end face on the incident side of the one-dimensional photonic crystal 2 is a vertical end face, the propagating light 8 can be a propagating light propagating by a mode on the Brillouin zone boundary. For example, a phase grating may be provided on the end face on the incident side of the one-dimensional photonic crystal 2 so that the incident light 5a is incident on the one-dimensional photonic crystal 2 via the phase grating. Further, in the case of a waveguide element that does not require incident light to enter, there is no need to provide the light input section 19. For example, a waveguide element that uses laser oscillation light generated by external energy as propagating light 8 In the case of a child, it is not necessary to provide the optical input unit 19.
[0091] 尚、本実施の形態の導波路素子 10bにおける各条件は、バンド計算によって求め ればよい。 [0091] Each condition in the waveguide element 10b of the present embodiment may be obtained by band calculation.
[0092] [実施の形態 4] [0092] [Embodiment 4]
本発明の実施の形態 4における導波路素子について、図を参照しながら説明する A waveguide element according to Embodiment 4 of the present invention will be described with reference to the drawings.
。図 10は、本発明の実施の形態 4における導波路素子の構成を示す斜視図である。 . FIG. 10 is a perspective view showing the configuration of the waveguide element in the fourth exemplary embodiment of the present invention.
[0093] 本実施の形態の導波路素子 30と上記実施の形態 1の導波路素子 10とは、 1次元 フォトニック結晶の構成が異なっている以外は、略同様の構成である。従って、図 10 において、図 1に示す部材と同様の機能を有する部材には同一の参照符号を付し、 それらの説明は省略する。 [0093] The waveguide element 30 of the present embodiment and the waveguide element 10 of the first embodiment have substantially the same configuration except that the configuration of the one-dimensional photonic crystal is different. Therefore, in FIG. 10, members having the same functions as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.
[0094] 図 10に示すように、本実施の形態の導波路素子 30は、基板 1と、基板 1上に設けら れた 1次元フォトニック結晶 32と、 1次元フォトニック結晶 32内に光を入射させる光入 力部 3と、 1次元フォトニック結晶 32から出射された光が導かれる光出力部 4とを備え ている。 As shown in FIG. 10, the waveguide element 30 of the present embodiment includes a substrate 1, a one-dimensional photonic crystal 32 provided on the substrate 1, and light in the one-dimensional photonic crystal 32. And a light output unit 4 through which the light emitted from the one-dimensional photonic crystal 32 is guided.
[0095] 1次元フォトニック結晶 32は、屈折率の異なる 2種類の物質が Y軸方向（基板 1の厚 さ方向）に周期的に交互に積層されて構成された積層構造体からなる。 1次元フォト ニック結晶 32を構成する各物質の層厚は一定であり、このため、 1次元フォトニック結 晶 32は、一方向（Y軸方向）にのみ屈折率周期性を有する。また、 1次元フォトニック 結晶 32の上面 (基板 1の反対側の面）の両端部には、それぞれ入射側回折格子 32a 及び出射側回折格子 32bが設けられている。具体的には、積層構造体である 1次元 フォトニック結晶 32の上面 (XZ平面に平行な面）に、均等な間隔で X軸方向に延び る複数の溝を形成することにより、入射側回折格子 32a及び出射側回折格子 32bが 設けられている。  The one-dimensional photonic crystal 32 is composed of a laminated structure in which two kinds of substances having different refractive indexes are periodically and alternately laminated in the Y-axis direction (the thickness direction of the substrate 1). The thickness of each material constituting the one-dimensional photonic crystal 32 is constant, and therefore the one-dimensional photonic crystal 32 has a refractive index periodicity only in one direction (Y-axis direction). Further, an incident side diffraction grating 32a and an emission side diffraction grating 32b are provided at both ends of the upper surface of the one-dimensional photonic crystal 32 (the surface on the opposite side of the substrate 1). Specifically, incident-side diffraction is formed by forming a plurality of grooves extending in the X-axis direction at equal intervals on the upper surface (a surface parallel to the XZ plane) of the one-dimensional photonic crystal 32 that is a laminated structure. A grating 32a and an output side diffraction grating 32b are provided.
[0096] 次に、本実施の形態の導波路素子 30の動作について説明する。  [0096] Next, the operation of the waveguide element 30 of the present exemplary embodiment will be described.
[0097] まず、光ファイバ 3aを伝播してきた入射光 5は、コリメータレンズ 3bで平行光とされ た後、対物レンズ 3cで集光されて、基板 1に入射される。光入力部 3からの光 (入射 光 5)は、基板 1内を伝播した後、 1次元フォトニック結晶 32内に、 1次元フォトニック結 晶 32の底面（上面に対向する面)力 入射される。 1次元フォト ック結晶 32内を伝 播した入射光 5は、入射側回折格子 32aで反射し、これ〖こより、 1次元フォトニック結 晶 32内に、フォトニックバンド構造におけるブリルアンゾーン境界上のモードによって 伝播する伝播光が生じる。この伝播光は、出射側回折格子 32bで反射して、 1次元フ オトニック結晶 32の底面側（基板 1側）へと進路が変更される。 1次元フォトニック結晶 32の底面から出射された出射光 6は、基板 1を透過して光出力部 4に導かれる。 First, the incident light 5 propagating through the optical fiber 3a is converted into parallel light by the collimator lens 3b, then condensed by the objective lens 3c, and incident on the substrate 1. The light from the light input unit 3 (incident light 5) propagates through the substrate 1 and then enters the bottom surface of the one-dimensional photonic crystal 32 (surface facing the top surface) into the one-dimensional photonic crystal 32. The 1D photonic crystal 32 The incident incident light 5 is reflected by the incident-side diffraction grating 32a, and from this, propagation light propagates in the one-dimensional photonic crystal 32 due to the mode on the Brillouin zone boundary in the photonic band structure. The propagating light is reflected by the exit-side diffraction grating 32b, and its path is changed to the bottom surface side (substrate 1 side) of the one-dimensional photonic crystal 32. The outgoing light 6 emitted from the bottom surface of the one-dimensional photonic crystal 32 passes through the substrate 1 and is guided to the light output unit 4.
[0098] 入射側回折格子 32a及び出射側回折格子 32bの設計や、 1次元フォトニック結晶 3 2の設計は、バンド計算を用いて行われる。そして、これにより、ブリルアンゾーン境界 上のモードによって伝播する伝播光が生じる条件を求めることができる。  The design of the entrance-side diffraction grating 32a and the exit-side diffraction grating 32b and the design of the one-dimensional photonic crystal 32 are performed using band calculation. This makes it possible to determine the conditions under which the propagating light propagates by the mode on the Brillouin zone boundary.
[0099] 1次元フォトニック結晶 32は、入射側回折格子 32a及び出射側回折格子 32bのい ずれか一方のみを備えていてもよい。そして、その場合には、入射側回折格子 32a 又は出射側回折格子 32bが設けられていない方の 1次元フォトニック結晶 32の端面 を傾斜面とすればよい。また、入射側回折格子 32a又は出射側回折格子 32bが設け られて ヽな 、方の 1次元フォトニック結晶 32の端面に位相格子を設けるようにしてもよ い。これにより、ブリルアンゾーン境界上のモードによって伝播する伝播光が生じるよ うに、 1次元フォトニック結晶 32内に光を入射させることも、 1次元フォトニック結晶 32 力 出射された光を光出力部に導くこともできる。  The one-dimensional photonic crystal 32 may include only one of the incident side diffraction grating 32a and the emission side diffraction grating 32b. In that case, the end face of the one-dimensional photonic crystal 32 on which the incident-side diffraction grating 32a or the emission-side diffraction grating 32b is not provided may be an inclined surface. Further, a phase grating may be provided on the end face of the one-dimensional photonic crystal 32, which is provided with the incident side diffraction grating 32a or the emission side diffraction grating 32b. This allows light to be incident into the one-dimensional photonic crystal 32 so that propagating light propagates depending on the mode on the Brillouin zone boundary. It can also be guided.
[0100] 次に、上記実施の形態 1ないし上記実施の形態 4のいずれかの導波路素子 10、 1 Oa、 10b又は 30を用いた光回路と、電子回路とを組み合わせた具体例について説 明する。図 11は、本発明の一実施の形態における導波路素子を用いた光回路と、 電子回路とを組み合わせた具体例を示す斜視図である。  [0100] Next, a specific example in which an optical circuit using any one of the waveguide elements 10, 1 Oa, 10b, or 30 of Embodiment 1 to Embodiment 4 and an electronic circuit are combined will be described. To do. FIG. 11 is a perspective view showing a specific example in which an optical circuit using a waveguide element according to an embodiment of the present invention and an electronic circuit are combined.
[0101] 図 11に示すように、電子回路 42の上方には、マイクロレンズ 4 laが複数配列された レンズアレイ 41が配置されている。また、レンズアレイ 41の上方には、上記実施の形 態 1の導波路素子と同様の機能を有する導波路素子を備えた光回路 40が配置され ている。  As shown in FIG. 11, a lens array 41 in which a plurality of microlenses 4 la are arranged is arranged above the electronic circuit 42. Further, above the lens array 41, an optical circuit 40 including a waveguide element having the same function as the waveguide element of the first embodiment is disposed.
[0102] 電子回路 42の上面には、垂直方向の光信号を出射する VCSEL (Vertical Cavity Semiconductor Emission Laser) 42a及び受光セル 42bが設けられており、電子回路 42の端面には、電気信号を入出力するための導線 42cが設けられている。  [0102] The upper surface of the electronic circuit 42 is provided with a VCSEL (Vertical Cavity Semiconductor Emission Laser) 42a and a light receiving cell 42b for emitting an optical signal in the vertical direction. Conductive wire 42c is provided for output.
[0103] また、光回路 40には、入射側あるいは出射側の傾斜面 40aが複数設けられている 。光回路 40は、図示されていないが 1次元フォトニック結晶を備えており、傾斜面 40a は当該 1次元フォトニック結晶に形成されている。傾斜面 40aに光が入射されると、そ の光は 1次元フォトニック結晶内をブリルアンゾーン境界上のモードによって伝播する 伝播光となり、対応する傾斜面 40aから光が出射される。ここで、マイクロレンズ 41a は、光入力部又は光出力部に相当している。 [0103] Further, the optical circuit 40 is provided with a plurality of incident-side or emission-side inclined surfaces 40a. . Although not shown, the optical circuit 40 includes a one-dimensional photonic crystal, and the inclined surface 40a is formed in the one-dimensional photonic crystal. When light is incident on the inclined surface 40a, the light is propagated in the one-dimensional photonic crystal by a mode on the Brillouin zone boundary, and the light is emitted from the corresponding inclined surface 40a. Here, the microlens 41a corresponds to a light input unit or a light output unit.
[0104] 例えば、電子回路 42に電気信号が入力されると、 VCSEL42aから信号光もしくは 制御光がレンズアレイ 41に向かって出力される。その光 43は、マイクロレンズ 41aを 介して傾斜面 40aに入射される。信号光もしくは制御光は、導波路素子によって処理 されて、入射した傾斜面 40aとは異なる傾斜面 40aからレンズアレイ 41に向かって出 射される。その光 43は、マイクロレンズ 41aを介して受光セル 42bに入力される。  For example, when an electric signal is input to the electronic circuit 42, signal light or control light is output from the VCSEL 42 a toward the lens array 41. The light 43 enters the inclined surface 40a through the microlens 41a. The signal light or the control light is processed by the waveguide element, and is emitted toward the lens array 41 from the inclined surface 40a different from the incident inclined surface 40a. The light 43 is input to the light receiving cell 42b through the microlens 41a.
[0105] 以上のような構成とすることにより、フレキシブルな電子的処理と光による高速処理 の両方の長所を利用することができる。また、図 11に示す構成によれば、光回路 40 と電子回路 42とが分離して配置されているので、光回路 40と電子回路 42を、全く別 の材料及びプロセスを用いて作製することができる。すなわち、光回路 40と電子回路 42を、無駄なく効率良く作製することができる。尚、同一基板上に光回路 40と電子回 路 42とを重ねて集積ィ匕してもよ ヽ。  [0105] With the configuration described above, the advantages of both flexible electronic processing and high-speed processing using light can be used. Further, according to the configuration shown in FIG. 11, since the optical circuit 40 and the electronic circuit 42 are arranged separately, the optical circuit 40 and the electronic circuit 42 are manufactured using completely different materials and processes. Can do. That is, the optical circuit 40 and the electronic circuit 42 can be efficiently manufactured without waste. Note that the optical circuit 40 and the electronic circuit 42 may be stacked and integrated on the same substrate.
[0106] 尚、ここでは、上記実施の形態 1の導波路素子と同様の機能を有する導波路素子 を備えた光回路 40を例に挙げて説明したが、上記実施の形態 2ないし上記実施の 形態 4の導波路素子と同様の機能を有する導波路素子を備えたものであってもよい  Here, the optical circuit 40 provided with the waveguide element having the same function as the waveguide element of the first embodiment has been described as an example, but the second embodiment to the second embodiment are described. It may be provided with a waveguide element having the same function as the waveguide element of form 4
[0107] (実施例） [Example]
以下に、上記実施の形態 1における導波路素子を実際に作製して、その光学特性 を測定した結果を示す。図 12は、本発明の実施例における導波路素子の構成を示 す側面図である。尚、図 12において、図 1、図 7に示す部材と同様の機能を有する部 材には同一の参照符号を付している。  The results of actually producing the waveguide device in the first embodiment and measuring the optical characteristics are shown below. FIG. 12 is a side view showing the configuration of the waveguide element in the example of the present invention. In FIG. 12, parts having the same functions as those shown in FIGS. 1 and 7 are given the same reference numerals.
[0108] まず、本実施例の導波路素子 50の構成について説明する。  First, the configuration of the waveguide element 50 of the present embodiment will be described.
[0109] 導波路のコアである 1次元フォトニック結晶 2は、石英力もなる平行平面基板 1 (100 mm X 20mm X lmm)の上面に、真空蒸着法により、 Ta O の薄膜と SiO の薄膜 とを交互に複数積層して形成されている。 Ta O の薄膜の膜厚は 424nmであり、 Si [0109] The one-dimensional photonic crystal 2 that is the core of the waveguide is a Ta 2 O thin film and SiO 2 thin film formed on the upper surface of a parallel flat substrate 1 (100 mm X 20 mm X lmm) that also has quartz force by vacuum evaporation. Are alternately stacked. The thickness of the Ta O thin film is 424 nm, and Si
2 5  twenty five
O の薄膜の膜厚は 106nmである。これらは 10層形成されている力 最上層の SiO The thickness of the O 2 thin film is 106 nm. These are the forces formed by 10 layers.
2 2 の薄膜はクラッド 51として機能し、その膜厚は約 2000nmである。つまり、本実施例 においては、 9層構成の 1次元フォトニック結晶 2の上に、クラッド 51として SiO 保護 The thin film of 2 2 functions as the clad 51, and the film thickness is about 2000 nm. In other words, in this example, the SiO protection as the cladding 51 is formed on the one-dimensional photonic crystal 2 having the nine-layer structure.
2 層が形成されている。上記数値より、 1次元フォトニック結晶 2の屈折率周期は 530η mとなる。尚、 1次元フォトニック結晶 2の幅 (X軸方向の長さ）を 10mmとし、 1次元フ オトニック結晶 2の長さ Lが 24. 5mm及び 39. 5mmの 2つの場合について光学特性 の測定を行った。また、 XZ平面と入射側傾斜面 2a及び出射側傾斜面 2bとのなす角 度 (傾斜角度）がそれぞれ 27° となるように、 1次元フォトニック結晶 2の両端面が斜 めに切断してポリッシュ面とされている。さらに、入射側傾斜面 2a及び出射側傾斜面 2bには、真空蒸着法により、厚さ 150nmの銀による反射層 21a、 21bがそれぞれ形 成されている。  Two layers are formed. From the above values, the refractive index period of the one-dimensional photonic crystal 2 is 530 η m. The optical characteristics were measured for two cases where the width (length in the X-axis direction) of the one-dimensional photonic crystal 2 was 10 mm and the length L of the one-dimensional photonic crystal 2 was 24.5 mm and 39.5 mm. went. In addition, both end surfaces of the one-dimensional photonic crystal 2 are cut obliquely so that the angles (tilt angles) formed by the XZ plane, the incident side inclined surface 2a, and the output side inclined surface 2b are 27 °, respectively. It is a polished surface. Further, reflective layers 21a and 21b made of silver having a thickness of 150 nm are formed on the incident side inclined surface 2a and the emission side inclined surface 2b by a vacuum deposition method, respectively.
[0110] 光入力部 3は、通信用シングルモードファイバ（SMF、波長 1550nm仕様、開口数 NA=0. 1)である光ファイバ 3aを伝播してきた入射光 5を、焦点距離 11. 3mmの非 球面レンズであるコリメータレンズ 3bによって平行光束に変換する。さらに、光入力部 3は、当該平行光束を、曲率半径 2. Ommの円筒状平凸レンズ (材質は光学ガラス B K7、中心厚さ 3. 8mm,焦点距離 3. 9mm)である対物レンズ 3cによって線状の焦 点に変換する。この線状の焦点は、 1次元フォトニック結晶 2の底面 (XZ平面に平行 な面）に対して垂直に入射される。すなわち、 1次元フォトニック結晶 2の底面と入射 光 5の光軸とのなす角度は 90° である。焦点を線状としたのは、導波路のコアとなる 1次元フォトニック結晶 2がスラブ状であるからである。  [0110] The optical input unit 3 transmits incident light 5 propagating through an optical fiber 3a, which is a single-mode fiber for communication (SMF, wavelength 1550 nm specification, numerical aperture NA = 0. 1), with a focal length of 11.3 mm. The collimator lens 3b, which is a spherical lens, is converted into a parallel light beam. Further, the light input unit 3 transmits the parallel light beam by an objective lens 3c which is a cylindrical plano-convex lens (material is optical glass B K7, center thickness 3.8 mm, focal length 3.9 mm) having a curvature radius of 2. Omm. Convert to linear focus. This linear focal point is incident perpendicular to the bottom surface of the one-dimensional photonic crystal 2 (a plane parallel to the XZ plane). That is, the angle between the bottom surface of the one-dimensional photonic crystal 2 and the optical axis of the incident light 5 is 90 °. The focal point is linear because the one-dimensional photonic crystal 2 that becomes the core of the waveguide has a slab shape.
[0111] 光出力部 4は、光入力部 3と同様の光学系を逆に用いたものであり、光出力部 4に よって出射光 6の取り出しが行われる。尚、本実施例における 1次元フォトニック結晶 2のバンド図は、 λ = 1550nmに相当する周波数において、図 4、図 6に示した形  The light output unit 4 uses the same optical system as the light input unit 3 in reverse, and the light output unit 4 extracts the emitted light 6. Note that the band diagram of the one-dimensional photonic crystal 2 in this example has the shape shown in FIGS. 4 and 6 at a frequency corresponding to λ = 1550 nm.
0  0
状となる。  It becomes a shape.
[0112] 入射側及び出射側の SMF (光ファイバ 3a、 4a)を、光ベクトルアナライザ (米国 Lun a Technologies Inc.製の OVA— CT型）に接続して、導波路素子 50の光学特性（ジョ ーンズマトリックスの全要素）を評価した。 [0113] 以下に、本実施例の測定結果を示す。 [0112] The SMFs (optical fibers 3a and 4a) on the incident side and the outgoing side are connected to an optical vector analyzer (OVA-CT type manufactured by Lun a Technologies Inc., USA), and the optical characteristics of the waveguide element 50 (JO All elements of the corn matrix were evaluated. [0113] The measurement results of this example are shown below.
[0114] 図 13は、本実施例における、 L = 24. 5mmの場合のインパルス応答を示すグラフ である。また、図 14は、本実施例における、 L = 39. 5mmの場合のインパルス応答 を示すグラフである。図 13、図 14において、横軸は遅延時間、縦軸は振幅である。 図 13、図 14に示すように、いずれの場合においても、ノイズとなるモードのピークが 僅かに認められる力 ほぼ単一のモード（ブリルアンゾーン境界上のモード）による伝 播であることが分かる。このように、本実施例の導波路素子 50によれば、ブリルアンゾ ーン境界上のモードを単一モードで伝播させることができる。  FIG. 13 is a graph showing an impulse response when L = 24.5 mm in the present example. FIG. 14 is a graph showing an impulse response when L = 39.5 mm in this example. 13 and 14, the horizontal axis represents the delay time, and the vertical axis represents the amplitude. As shown in Fig. 13 and Fig. 14, it can be seen that in both cases, the force is such that the noise mode peak is slightly observed, and the propagation is almost a single mode (mode on the Brillouin zone boundary). Thus, according to the waveguide element 50 of the present embodiment, the mode on the Brillouin zone boundary can be propagated in a single mode.
[0115] 図 15は、本実施例における、 L = 24. 5mmの場合の挿入損失を示すグラフである 。また、図 16は、本実施例における、 L = 39. 5mmの場合の挿入損失を示すグラフ である。図 15、図 16において、横軸は波長、縦軸は挿入損失である。図 15に示すよ うに、 L = 24. 5mmの場合のピーク波長における挿入損失は 19. 8dBである。また、 図 16に示すように、 L = 39. 5mmの場合のピーク波長における挿入損失は 28. 7d Bである。  FIG. 15 is a graph showing insertion loss when L = 24.5 mm in this example. FIG. 16 is a graph showing the insertion loss when L = 39.5 mm in this example. 15 and 16, the horizontal axis is wavelength and the vertical axis is insertion loss. As shown in Figure 15, the insertion loss at the peak wavelength when L = 24.5 mm is 19.8 dB. As shown in Fig. 16, the insertion loss at the peak wavelength when L = 39.5 mm is 28.7 dB.
[0116] 尚、本実施例においては、入射光 5及び出射光 6の光軸が基板 1に対して垂直とな るようにされて!ヽるが (入射光 5及び出射光 6の基板 1に対する入射角及び出射角は 0° である）、入射光 5及び出射光 6の進路を変更して、入射角及び出射角を変更す ることは容易〖こ実現することができる。  In the present embodiment, the optical axes of the incident light 5 and the outgoing light 6 are set to be perpendicular to the substrate 1 (the substrate 1 for the incident light 5 and the outgoing light 6). It is possible to easily change the incident angle and the outgoing angle by changing the paths of the incident light 5 and the outgoing light 6.
産業上の利用可能性  Industrial applicability
[0117] 本発明によれば、垂直結合に適した導波路素子を実現することができる。従って、 この導波路素子を光回路に搭載し、その光回路と電子回路とを組み合わせることに より、光回路と電子回路のそれぞれの長所を生かした回路を作製することができる。 According to the present invention, a waveguide element suitable for vertical coupling can be realized. Therefore, by mounting this waveguide element on an optical circuit and combining the optical circuit and the electronic circuit, a circuit that takes advantage of the advantages of the optical circuit and the electronic circuit can be manufactured.

Claims

請求の範囲 The scope of the claims
[1] 一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に対して垂直な 底面と、前記底面に対して傾斜して!/、る入射側傾斜面及び Z又は出射側傾斜面とを 有する、コアであるフォトニック結晶と、  [1] Refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, an incident side inclined surface and Z or exit inclined with respect to the bottom surface! A core photonic crystal having a side inclined surface;
前記入射側傾斜面及び Z又は出射側傾斜面に対応させて前記フォトニック結晶の 底面側に配置された光入力部及び Z又は光出力部とを備え、  A light input portion and a Z or light output portion arranged on the bottom surface side of the photonic crystal corresponding to the incident side inclined surface and Z or the outgoing side inclined surface,
前記光入力部は、前記フォトニック結晶内に前記底面を介して光を入射させ、前記 光入力部によって前記フォトニック結晶内に入射された光は、前記入射側傾斜面で 反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンドによる伝播光を 生じさせ、  The light input unit causes light to be incident on the photonic crystal through the bottom surface, and the light incident on the photonic crystal by the light input unit is reflected by the incident side inclined surface, and Propagation light is generated in the photonic crystal by a band on the Brillouin zone boundary,
前記光出力部には、前記フォトニック結晶内を伝播するブリルアンゾーン境界上の バンドによる伝播光が前記出射側傾斜面で反射して、前記フォトニック結晶の前記底 面から出射された光が導かれる導波路素子。  The light output from the bottom surface of the photonic crystal is guided to the light output portion by the propagation light from the band on the Brillouin zone boundary propagating in the photonic crystal being reflected by the emission side inclined surface. Waveguide element to be cut.
[2] 前記入射側傾斜面及び Z又は出射側傾斜面に、反射層が形成された請求項 1に 記載の導波路素子。  [2] The waveguide element according to [1], wherein a reflection layer is formed on the incident side inclined surface and the Z or emission side inclined surface.
[3] 前記反射層が金属膜又は誘電体多層膜からなる請求項 2に記載の導波路素子。  3. The waveguide element according to claim 2, wherein the reflective layer is made of a metal film or a dielectric multilayer film.
[4] 一方向に屈折率周期性を有し、前記屈折率周期性を有する方向に対して垂直な 底面と、前記底面に対向する上面と、前記上面に設けられた入射側回折格子及び Z又は出射側回折格子とを有する、コアであるフォトニック結晶と、 [4] A refractive index periodicity in one direction, a bottom surface perpendicular to the direction having the refractive index periodicity, a top surface facing the bottom surface, an incident-side diffraction grating provided on the top surface, and Z Or a photonic crystal as a core having an output side diffraction grating;
前記入射側回折格子及び Z又は出射側回折格子に対応させて前記フォトニック結 晶の底面側に配置された光入力部及び Z又は光出力部とを備え、  A light input unit and a Z or light output unit arranged on the bottom side of the photonic crystal corresponding to the incident side diffraction grating and the Z or output side diffraction grating,
前記光入力部は、前記フォトニック結晶内に前記底面を介して光を入射させ、前記 光入力部によって前記フォトニック結晶内に入射された光は、前記入射側回折格子 で反射して、前記フォトニック結晶内にブリルアンゾーン境界上のバンドによる伝播光 を生じさせ、  The light input unit causes light to enter the photonic crystal through the bottom surface, and the light input into the photonic crystal by the light input unit is reflected by the incident-side diffraction grating, and Propagation light is generated in the photonic crystal by a band on the Brillouin zone boundary,
前記光出力部には、前記フォトニック結晶内を伝播するブリルアンゾーン境界上の バンドによる伝播光が前記出射側回折格子で反射して、前記フォトニック結晶の前記 底面から出射された光が導かれる導波路素子。 前記フォトニック結晶内に入射される光の進行方向及び Z又は前記フォトニック結 晶から出射される光の進行方向が、前記フォトニック結晶の前記屈折率周期性を有 する方向と同一である請求項 1又は 4に記載の導波路素子。 The light output from the bottom surface of the photonic crystal is guided to the light output part by propagating light from a band on the Brillouin zone boundary propagating in the photonic crystal by the output side diffraction grating. Waveguide element. The traveling direction of light incident into the photonic crystal and the traveling direction of light emitted from the Z or the photonic crystal are the same as the direction having the refractive index periodicity of the photonic crystal. Item 5. The waveguide device according to Item 1 or 4.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007097228A1 (en) * 2006-02-23 2007-08-30 Nippon Sheet Glass Company, Limited Waveguide optical element

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03274513A (en) * 1990-03-26 1991-12-05 Matsushita Electric Ind Co Ltd Optical coupling device
JPH0467107A (en) * 1990-07-09 1992-03-03 Matsushita Electric Ind Co Ltd Optical coupler
US5282080A (en) * 1991-12-09 1994-01-25 Sdl, Inc. Surface coupled optical amplifier
JPH0973026A (en) * 1995-09-05 1997-03-18 Mitsubishi Heavy Ind Ltd Integrated type optical connecting structure
JPH11153719A (en) * 1997-09-17 1999-06-08 Lucent Technol Inc Optical integrated circuit having planar waveguide turning mirror
JP2000056168A (en) * 1998-08-05 2000-02-25 Seiko Epson Corp Optical transmitter
JP2000193580A (en) * 1998-12-25 2000-07-14 Sharp Corp Optical waveguide type probe, light detecting head and production of them
JP2000235127A (en) * 1999-02-15 2000-08-29 Nippon Telegr & Teleph Corp <Ntt> Optoelectronic integrated circuit and its production
US20040007662A1 (en) * 2002-07-02 2004-01-15 Yakov Sidorin Optical characterisation device
WO2004081626A1 (en) * 2003-03-04 2004-09-23 Nippon Sheet Glass Company Limited Waveguide device using photonic crystal
JP2005043886A (en) * 2003-07-18 2005-02-17 Nippon Sheet Glass Co Ltd Diffraction device using photonic crystal

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03274513A (en) * 1990-03-26 1991-12-05 Matsushita Electric Ind Co Ltd Optical coupling device
JPH0467107A (en) * 1990-07-09 1992-03-03 Matsushita Electric Ind Co Ltd Optical coupler
US5282080A (en) * 1991-12-09 1994-01-25 Sdl, Inc. Surface coupled optical amplifier
JPH0973026A (en) * 1995-09-05 1997-03-18 Mitsubishi Heavy Ind Ltd Integrated type optical connecting structure
JPH11153719A (en) * 1997-09-17 1999-06-08 Lucent Technol Inc Optical integrated circuit having planar waveguide turning mirror
JP2000056168A (en) * 1998-08-05 2000-02-25 Seiko Epson Corp Optical transmitter
JP2000193580A (en) * 1998-12-25 2000-07-14 Sharp Corp Optical waveguide type probe, light detecting head and production of them
JP2000235127A (en) * 1999-02-15 2000-08-29 Nippon Telegr & Teleph Corp <Ntt> Optoelectronic integrated circuit and its production
US20040007662A1 (en) * 2002-07-02 2004-01-15 Yakov Sidorin Optical characterisation device
WO2004081626A1 (en) * 2003-03-04 2004-09-23 Nippon Sheet Glass Company Limited Waveguide device using photonic crystal
JP2005043886A (en) * 2003-07-18 2005-02-17 Nippon Sheet Glass Co Ltd Diffraction device using photonic crystal

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
KITTAKA S. ET AL.: "1 Jigen Photonic Kessho ni yoru Koji Mode Doharo", 2005 NEN (HEISEI 17 NEN) SHUNKI DAI 52 KAI OYO BUTSURIGAKU KANKEI RENGO KOENKAI KOEN YOKOSHU, vol. 3, 29 March 2005 (2005-03-29), pages 1185 (LECTURE NO. 29P-YV-2), XP003005215 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007097228A1 (en) * 2006-02-23 2007-08-30 Nippon Sheet Glass Company, Limited Waveguide optical element
US7515804B2 (en) 2006-02-23 2009-04-07 Nippon Sheet Glass Company, Limited Optical waveguide device

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