WO2017086524A1 - Nanophotonic radiator using grid structure for application to photonic phased-array antenna - Google Patents

Nanophotonic radiator using grid structure for application to photonic phased-array antenna Download PDF

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Publication number
WO2017086524A1
WO2017086524A1 PCT/KR2015/012953 KR2015012953W WO2017086524A1 WO 2017086524 A1 WO2017086524 A1 WO 2017086524A1 KR 2015012953 W KR2015012953 W KR 2015012953W WO 2017086524 A1 WO2017086524 A1 WO 2017086524A1
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Prior art keywords
grating
light
light emitter
phase
optical
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PCT/KR2015/012953
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French (fr)
Korean (ko)
Inventor
박효훈
김종훈
한선규
박지환
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한국과학기술원
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Priority claimed from KR1020150168696A external-priority patent/KR101872077B1/en
Application filed by 한국과학기술원 filed Critical 한국과학기술원
Priority to US15/777,074 priority Critical patent/US10732483B2/en
Publication of WO2017086524A1 publication Critical patent/WO2017086524A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection
    • G02F1/295—Analog deflection from or in an optical waveguide structure]
    • G02F1/2955—Analog deflection from or in an optical waveguide structure] by controlled diffraction or phased-array beam steering

Definitions

  • the present invention relates to a light radiator structure for application to a photonic phased array antenna, and more particularly to a grating capable of emitting light waves in a free space.
  • a light diverter array structure We propose a light diverter array structure.
  • the present invention proposes a structure that constitutes a lattice structure using a semiconductor material and that can widen the scanning angle of the light beam formed from the phased array.
  • the scale of the proposed detailed grating is close to or smaller than the wavelength of light waves and is designed based on the concept of nanophotonics.
  • the optical phased array antenna may be used as a light source for scanning an optical beam for image scanning in a driverless vehicle, a robot, and the like.
  • the desirable performance of an optical phased array antenna for applications in various fields should be small in size, high in light beam divergence efficiency, forming a clear beam, and having a wide beam scanning range.
  • an optical phased array antenna based on semiconductor materials is required.
  • the present invention proposes a specific structure for the light emitter based on the semiconductor material.
  • the semiconductor material includes not only silicon and a compound material semiconductor, but also an insulator material such as silicon oxide and silicon nitride and metal thin film materials used to fabricate optical devices of these materials.
  • the light emitter for emitting light waves from the phased array antenna (corresponding to the antenna element in the present invention) has a lattice structure, but the array of light emitters is arranged in a matrix form, and each unit light emitter is arranged.
  • Optical power distribution lines directional couplers
  • optical delay lines optical delay lines
  • the functions of several functional elements are concentrated in one unit cell, so that the space occupied by the grating of the core light emitter is small, and the grating entering the small space is several micrometers in size. It must be small. Therefore, the smaller the size of the grating, the lower the divergence efficiency of the light waves, a problem that is difficult to obtain a high-performance beam.
  • the previous invention of the present lab proposed a phased array antenna as shown in FIG. 1 which can provide sufficient space in the light emitter portion.
  • the main elements constituting the phased array antenna in FIG. 1 are largely a light source 100, a light power distributor 101-1, 101-2, a power distributor, a phase controller 102, and a light. It consists of an emitter 104 (radiator). These components are connected by an optical waveguide 106. In addition, the optical waveguide 106 is also connected between the phase controller 102 and the light emitter 104. Since the connection waveguides have high density, coupling between the waveguides can occur, so the arrangement is important. , Phase-feeding line (103).
  • the optical power divider 101-1, 101-2, phase controller 102, and phase outside the 1 ⁇ M diverter array 105 to ensure sufficient space in the longitudinal direction of the light diverter 104.
  • the supply line 103 is arrange
  • the prior invention implements a (1xM) xN phased array by arranging N 1xM diverter arrays up and down independently to achieve a two-dimensional (2D) beam scanning function while providing sufficient space between neighboring 1xM arrays. Proposed that it can be secured.
  • the present invention proposes a light diverter structure that makes full use of the space in the longitudinal direction of the lattice structure suitable for the (1xM) xN phase arrangement.
  • the present invention is a detailed grating structure, to ensure the performance of the appropriate level of light emission, phase matching beam.
  • the present invention seeks to widen the range of angles at which the output light waves of the light emitters are radiated from the bidirectional light wave input method, and ultimately to widen the scanning range of the phase matched beams obtained in the phase array.
  • an optical diverter element constituting an optical phased array antenna includes: an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material; And a grating periodically formed above or below the optical waveguide, wherein the light diverter element receives an input light wave in one direction of the optical waveguide and the grating, and spaces the output light wave using scattering from the grating. To emit.
  • the light diverter element injects the input light wave in both directions of the optical waveguide and the grating to widen the longitudinal angular range from which the output light wave is radiated, and scatters the output light wave into space by using scattering from the grating. It can radiate.
  • At least one of geometric variables of the light emitter element including the width of the waveguide core, the thickness of the waveguide core, the width of the grating, the period of the grating and the depth of the grating.
  • the magnitude of may be a value within a diffraction limit that is half of the wavelength of the input light wave or close to a preset range for the diffraction limit.
  • the waveguide core may be formed of silicon.
  • the free space wavelength of the input light wave silver It can have a range.
  • the width Wg of the grating is the free space wavelength of the input light wave prepare It can have a range.
  • the depth of the grating can be adjusted to control the longitudinal distribution in which the output light waves are emitted.
  • the period of the grating can be adjusted to control the longitudinal radiation angle at which the output light wave is emitted.
  • the width of the grating can be adjusted to control the range of lateral radiation angles at which the output light waves are emitted.
  • an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material, and a grating periodically formed above or below the optical waveguide, the input light wave is one direction of the optical waveguide and the grating.
  • a light emitter array composed of light emitter elements which emit light into the space using scattering from the grating, the light emitter array being generated as an array of a plurality of light emitter elements, the plurality of light emitter elements
  • the number of beams is adjusted to control the lateral beam divergence angle of the phase matching beam formed by the phase interference of the output light waves emitted from each of the plurality of light diverter elements, and included in each of the plurality of light diverter elements.
  • the number of periods of the grating being radiated from each of the plurality of light emitter elements It is adjusted so as to control the longitudinal beam divergence angle of a coherent beam is formed in a phase of the interference wave power.
  • an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material, and a grating periodically formed above or below the optical waveguide, the input light wave is one direction of the optical waveguide and the grating.
  • the optical phased array antenna which is composed of a light emitter element which is incident on the light and emits an output light wave into space using scattering from the grating, is generated as an array of a plurality of light emitter elements, and the plurality of light emitter elements Supplying a phase that increases or decreases so as to have an equal phase difference to each of the plurality of light emitter elements, and performs beam steering in a transverse direction in the space with a phase matching beam by the phase arrangement of the plurality of light emitter elements. steering.
  • the present invention is a detailed grating structure, it is possible to ensure the performance of the appropriate level of light emission, phase matching beam.
  • the present invention can widen the range of angles at which the output light waves of the light emitters are radiated from the bidirectional light wave input method, and ultimately, widen the scanning range of the phase matched beams obtained in the phased array.
  • 1 is a schematic diagram showing the main elements constituting the optical phased array antenna proposed in the previous invention.
  • Figure 2 is a schematic diagram showing the basic structure of the light emitter according to an embodiment of the present invention.
  • 3 is a diffraction pattern emitted from a single grating structure according to one embodiment of the present nickname.
  • FIG. 6 shows the shape of a phase-matching beam emitted from a grating structure diverger array according to an embodiment of the present invention.
  • FIG. 7 is a simulation result illustrating a change in the shape of a phase-matching beam according to a change in the number Ng of grating periods in an emanator in a grating structure emanator array according to an embodiment of the present invention.
  • FIG. 8 is a diagram illustrating a steering function of a phase matching beam by phase control in a phase arrangement of a lattice structure according to an embodiment of the present disclosure.
  • FIG. 9 is a schematic diagram showing the extension of the longitudinal range of the output light wave emitted by bidirectional incidence of the input light wave in the grating structure according to the embodiment of the present nickname.
  • Figure 2 is a schematic diagram showing the basic structure of the light emitter according to an embodiment of the present invention. Specifically, Figure 2 (a) is a side cross-sectional view showing a light emitter, (b) is a bird's eye view showing the light emitter.
  • the grating structure is generally located at the end of the optical waveguide core 200 and is formed on the upper or lower portion of the optical waveguide core 200.
  • the lattice structure is not limited to the optical waveguide core 200 portion, but can also be formed around the core 200.
  • the waveguide may be a general semiconductor or insulator material, and may be manufactured in a waveguide structure such as rib type or channel type. In this case, only the core portion of the waveguide is shown as an example of the channel type optical waveguide, and a grating formed on the top of the waveguide core 200 is illustrated in order to present major design variables.
  • the wavelength of the input light wave 202 may be selected from a wavelength band having a low optical loss in the optical waveguide 200.
  • the wavelength of the input light wave 202 is The wavelength (wavelength in free space) band of is preferable.
  • the main design variables (geometric variables) in the light emitter device are the period of the grating ), The width of the valley 205 portion of the unit grid ( ), The width of the hill portion of the unit grid (206) ( ), The number of cycles in the grid (Ng), the length of the grid ( ), The depth of the grating (depth of the valleys of the lattice) (Hs), the thickness (Hc) of the grating partial waveguide core 200-1, the width of the grating (Wg) in the waveguide core 200, and the spacing between the unit diverters (Pitch) (Dr) and the like.
  • the present invention proposes a detailed grating structure in which light wave radiation efficiency, a range of radiation angles, a shape of a phase-matched beam formed in a phased array, a scanning angle range, and the like can be obtained at an appropriate level.
  • the input light wave 202 is illustrated as being incident only in one direction (from left to right) in the drawing, the input light wave 202 is not limited thereto, but is input in both directions of the grating in order to widen the scanning angle range.
  • An antenna structure for injecting light waves may also be proposed. Detailed description thereof will be described with reference to FIG. 9.
  • the radiation angle of the far field of the output light wave 203 radiated from the grating structure may be designed by using Equation 1 by the diffraction principle.
  • Equation 1 Is the center wavelength in the free space of the input light wave 202, Is the period of the grating, n eff is the effective index of the optical waveguide (the entire waveguide including the core and clad) containing the grating, n c is the cladding of the cladding over the core Refractive index, and Represents a radiation angle (for example, an angle from the normal direction of the grating surface) of the diffraction pattern formed by diffraction of light waves scattered from the periodic grating, which corresponds to the center of the light intensity.
  • a radiation angle for example, an angle from the normal direction of the grating surface
  • the effective refractive index n eff is determined according to the structure of the optical waveguide based on the material of the optical waveguide and the refractive index according to the wavelength of the optical waveguide.
  • FIG. 3 is a diffraction pattern emitted from a single grating structure according to one embodiment of the present nickname.
  • (a) and (c) of FIG. 3 are values of design variables for two lattice structures having different depths of lattice valleys, and (b) and (d) are near fields radiated from the lattice structure.
  • -field) pattern for example, (b) and (d) are radiation characteristics simulated with a finite-difference time-domain (FDTD) for the grid). That is, Figure 3 is an example showing the influence of the main variables that can control the distribution of the output light wave emitted in the longitudinal direction of the grating.
  • the radiation characteristics of (b) and (d) are the near-field of the electric field of light waves on the longitudinal section of the grating (XY plane in Fig. 2 (a)), and the intensity of the field is expressed in color. .
  • the field is divided into several branches in the longitudinal direction as shown in (b) and (d), which is a phenomenon in which the degree of scattering is different depending on lattice irregularities.
  • the overall field strength may weaken further along the length of the grating.
  • the longitudinal distribution of the radiation field is mainly affected by the depth of the grating valleys, but can also be influenced by the wavelength of the light waves, the thickness of the optical waveguide core and the width of the grating. Considering the influence of these variables, the electric field of the output light wave is roughly in the range close to the values of the parameters illustrated in (a) and (c) when the relative ratio of the grating valley depth to the thickness of the optical waveguide core is approximately 1/4 or more.
  • More than 80% of the grating can be radiated into the space within 8 cycles of the grating, and if the relative ratio of the grating valley depth to the thickness of the optical waveguide core is less than 1/4, then more than 80% of the electric field of the output lightwave is 5 cycles of the grating Up to 8 cycles or more.
  • FIG. 4 is a result showing the effect of the lattice period on the radiation angle in a single lattice structure according to an embodiment of the present invention. Specifically, (a) of FIG. 4 is a value of design variables, and (b) is fixed to a design variable of (a) to change the lattice period. Longitudinal radial angle of the far-field This is a simulation result showing the change.
  • the lattice period in (b) It can be seen that a small change in can change the radiation angle over a wide range.
  • the effective refractive index n eff is about 2.8 and is not significantly affected by the period of the lattice.
  • the effective refractive index is sensitive to the width Wg of the optical waveguide core in which the grating is formed, the refractive index of the semiconductor material of the optical waveguide core is 3.5, the width of the core is 0.3, When in the range, the effective refractive index of the grating-formed optical waveguide is within the range of 2.5 ⁇ n eff ⁇ 3.0.
  • the radial angle I is the relative ratio of the period of the grating to the free-space wavelength Of It tends to be determined by the relative difference between the value and the effective refractive index n eff .
  • the range close to the values of the variables exemplified in (a) Of Approximate value can vary between 0 degrees and 60 degrees.
  • the longitudinal radiation angle range can be made larger than 60 degrees, but the radiation efficiency is lowered, resulting in less utility.
  • Equation 2 The following describes the variables that affect the lateral divergence range of a single diverger. Based on the classical Gaussian beam divergence principle, the transverse angular range of light waves emitted by a single diverger May be represented by Equation 2.
  • Wg is a variable corresponding to the size of the aperture diameter, which is the origin of Gaussian beam divergence, and may be the width Wg of the lattice in the light diverter of the lattice structure.
  • the lateral range of the far field radiated in the single lattice structure is mainly a relative ratio of the width of the lattice to the wavelength, that is, / Wg, the narrower the relative width of the grid, the wider the lateral range of the far field.
  • Equation 2 only shows the approximate relationship of the variables, the radiation range in the structure of the embodiment of the present invention, which is a nanophotonic region can be confirmed by numerical simulation as shown in FIG.
  • FIG. 5 is a result showing the range of the far field radiated in a single lattice structure according to an embodiment of the present nickname. Specifically, (a) of FIG. 5 is a three-dimensional view showing the spatial coordinate system of the hemisphere (b), (b) is a simulation result showing the radiation range in a planar projection in the hemisphere spatial coordinate system.
  • the structure applied to FIG. 5 is an embodiment in which the transverse range is widely designed in the present invention, and main design variables including Wg are the same as in FIG. 4A.
  • the direction between W (0 degrees) and E (180 degrees) corresponds to the transverse direction of the lattice (Z in FIG. 2)
  • the N direction corresponds to the normal direction of the lattice (in FIG. 2).
  • Y direction, in equation (1) 0 degrees).
  • the electric field distribution radiated from the grating is radiated close to a cone shape having an elliptical cross section, as in (a), and as in (b), the longitudinal direction of the grating (between 90 and 270 degrees). More broadly in the transverse direction W (0 degrees) -E (180 degrees)).
  • the distribution of intensity in the WNE direction is the maximum in the vertical direction (N direction), and 1 / e 2 of this maximum intensity (1 / e of the maximum electric field, where the index e is approximately 2.72). Radial angle down to range Is beyond.
  • phase-matched beams are formed by the interference of the output light waves emitted from each light emitter in the 1 ⁇ M emitter array.
  • Lateral divergence angle of this phase-matched beam Can be represented by Equation 3 based on the classical Gaussian beam divergence principle.
  • Equation (3) Is a variable determined by assuming that the size of the aperture diameter, which is the origin of Gaussian beam divergence, is the entire width of the array.
  • the main variable affecting the lateral divergence angle of the phase matching beam is the relative ratio of the width of the grating to the wavelength ( / Wg) and the number M of diverters in the array.
  • Equation 3 indicates that the divergence angle of the phase-matching beam increases as the number M of diverters increases. Indicates a tendency to narrow. Equation 3 only shows an approximate relationship between the variables, and more specific forms may be confirmed by numerical simulations as shown in FIG. 6.
  • FIG. 6 illustrates the effect of the number M of diverters constituting the array on the behavior of the phase-matched beam when the diverger 1xM array is configured in a lattice structure according to an embodiment of the present invention. That is, FIG. 6 illustrates a phase arrangement of a 1xM array with a lattice structure according to an embodiment of the present invention, and shows the phase difference between each diverger. It is a simulation of the shape of the phase-matching beam emitted from the phased array when fixed to 0 degrees.
  • (a) of Figure 6 is the value of the design variables
  • (b) is a schematic diagram showing the radiation pattern of the beam in the hemisphere three-dimensional spatial coordinate system
  • (c)-(e) is the number M of diverters in the array Simulation results show the change of phase-matched beam shape according to.
  • the design variable of the emanator illustrated in (a) is a unit design variable illustrated in FIG. 5.
  • Ng 24 as an example.
  • the lateral divergence angle of the phase-matching beam It can be seen that the narrowing is 4.4 degrees, 2.3 degrees, 1.2 degrees. According to the simulation of the above conditions, when the number of diverters M is 64 or more, Can be further narrowed to below 0.8 degrees.
  • narrowing of the beam divergence angle may mean that resolution may be improved in image scanning. Therefore, the lateral resolution can be controlled by the number M of diverters.
  • the adjustment of the longitudinal divergence angle of the phase-matching beam is controlled by the length Lg of the grating of the diverter in the array, as shown in FIGS. 7 (c)-(e) described below. Can be.
  • Equation 4 is similar to Equation 2, and assumes that the longitudinal divergence angle of the phase-matching beam is determined in the longitudinal direction of the aperture diameter, ie, Lg, which is the origin of the Gaussian beam divergence.
  • the lateral range of the far-field far field radiated in the single grating structure is mainly a relative ratio of the width of the grating to the wavelength, that is, / Lg, the longer the grating Lg, i.e. the relative ratio As the / Lg decreases, the longitudinal divergence angle of the lattice match beam Can be narrowed.
  • Equation 4 only shows the approximate relationship of the variables, the radiation range in the structure of the embodiment of the present invention, which is a nanophotonic region can be confirmed by numerical simulation as shown in FIG.
  • FIG. 7 is a longitudinal divergence angle of a phase-matching beam of a phase-matching beam according to a change in the number of grid periods Ng in a grid-structure diverging array according to an embodiment of the present invention; Simulation results showing the change of.
  • the longitudinal divergence angle of the phase-matching beam is increased as the number of grating periods Ng is increased to 16, 20, and 24 (as the length of the grid Lg is increased). Are narrowed to 6.3 degrees, 5.2 degrees, and 3.3 degrees, respectively, and thus it can be seen that the longitudinal resolution can be improved.
  • FIG. 8 is a diagram illustrating a steering function of a phase matching beam by phase control in a phase arrangement of a lattice structure according to an embodiment of the present disclosure.
  • Figure 8 (a) is a value of the design variables
  • (b) is a schematic diagram showing the beam steering in the hemisphere three-dimensional spatial coordinate system
  • (c)-(e) is a phase difference Simulation results showing the phase-matched beam steering according to
  • a phase matching beam 1 801 with strong light intensity is formed near the center, that is, near the N direction.
  • two phase matching beams 2802 and 3 beams 803 having weak light intensity are also formed on both outer edges near the W and E directions. If the phase difference is increased from 0 degrees to 180 degrees, as shown in the comparison between (c) and (d), beam 1 801 moves in the E direction, and beam 2 802 is centered in the W direction (N direction). To the side. In this movement, the light intensity of the beam 1 801 is gradually weakened, and the light intensity of the beam 2 802 toward the W direction is gradually enhanced.
  • beam 1 801 and beam 2 802 move further in the E direction, and most of the field transitions to beam 2 802. Also, a new beam 4 804 appears in the W direction.
  • a plurality of beams may be steered in the phase modulation process, and the light intensity of the transition of the light wave field is changed between the beams.
  • the beam with the strongest light intensity is defined as the 0 th -order beam and the outer beams are defined as the high-order beam.
  • the phase difference in the phased array structure of the embodiment of the present invention Maximum transverse range of beam-steering when changing between and using both 0 th -order and high-order beams As shown in (b), Can go beyond If the steering angle is too large, there may be a problem in that the field of the high-order beam is weakened too much. Therefore, in order to maintain an appropriate level of the intensity of the light beam, It is preferable to change in the range and to use only 0 th- order beam.
  • the maximum transverse range of the beam-steering 'Is the phase difference Maximum transverse range of the scheme, varying between and using both 0 th -order beams and high-order beams Half of that, Will be reduced to / 2.
  • FIG. 9 is a schematic diagram showing the extension of the longitudinal range of the output light wave emitted by bidirectional incidence of the input light wave in the grating structure according to the embodiment of the present nickname.
  • the emission angle of the output light wave 903-1 is +.
  • the output light wave 903-2 has a radial angle of ⁇ when another input light wave 902-2 is directed from right to left. 2 can be sent to the other side. Therefore, the radiation angle is + by making the incidence of the input light waves 902-1 and 902-2 bidirectional in the same lattice structure. 1 and- It may be sent to the two angles of the two, it is possible to enlarge the longitudinal radiation range.
  • the configuration of the phased array antenna capable of bidirectional incidence can be realized by simply arranging the elements constituting the one-way incident phased array antenna of FIG. 1 in mirror symmetry.
  • the light source 100, the optical power divider (101-1, 101-2), the phase controller 102, the phase supply line 103 is disposed in the mirror mirror symmetrical components such as the diverter 104,
  • the phase supply lines on the right side are connected to the right side of the diverter.
  • the free-wavelength wavelength is 1550 nm for the silicon optical waveguide core, but the present invention is not limited thereto or limited.
  • the material of the optical waveguide core has a refractive index close to silicon.
  • the free space wavelength may also be set to an appropriate wavelength range, such that the above-described scale law may be applied.
  • the wavelength In a silicon waveguide, the wavelength The trend described above in the phosphorus range can be applied.
  • the lattice width Wg which is the main variable in the lattice structure light emitter In the range the above-described trends can be applied.
  • the structure of the grating is a uniform structure within the grating, but the parameters of the grating structure ( , , Hs, Wg, etc.) may be changed differently in the longitudinal direction of the grating.
  • the incident of light waves having a single wavelength is taken as an example, but the light waves having one or more center wavelengths or the light waves having a central wavelength may be incident on a wide range.
  • Ng number of grid periods
  • Hc thickness of the grating partial waveguide core
  • Wg width of the grating in the optical waveguide core
  • n eff Effective index of grating-formed optical waveguide
  • n c Refractive index of the clad covering the grating formed optical waveguide

Abstract

An optical radiator element constituting a photonic phased-array antenna and comprising: optical waveguides comprising a waveguide cladding and a waveguide core using a semiconductor material; and grids periodically formed at the upper or lower part of the optical waveguides, wherein the optical radiator element receives input light waves in one direction of the optical waveguides and grids and radiates output light waves to a space by using scattering from the grids.

Description

광 위상 배열 안테나에 적용을 위한 격자 구조를 이용한 나노포토닉 발산기 Nanophotonic Divider Using Lattice Structure for Application to Optical Phased Array Antenna
본 발명은 광 위상 배열 안테나(photonic phased array antenna)에 적용을 위한 광 발산기(radiator) 구조에 관한 것으로서, 보다 상세하게는 광파(light wave)를 넓은 공간(free space)으로 발산할 수 있는 격자 구조의 광 발산기 어레이 구조를 제안한다. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light radiator structure for application to a photonic phased array antenna, and more particularly to a grating capable of emitting light waves in a free space. We propose a light diverter array structure.
구체적으로, 본 발명은 반도체 소재를 이용하여 격자 구조를 구성하며, 위상 배열로부터 형성되는 광 빔의 스캐닝 각도를 넓힐 수 있는 구조들을 제안한다. 제안되는 세부 격자의 규모(scale)는 광파의 파장에 가깝거나 파장 보다 작으므로 나노포토닉스의 개념을 기반으로 설계된다.Specifically, the present invention proposes a structure that constitutes a lattice structure using a semiconductor material and that can widen the scanning angle of the light beam formed from the phased array. The scale of the proposed detailed grating is close to or smaller than the wavelength of light waves and is designed based on the concept of nanophotonics.
광 위상 배열 안테나는 무인자동차, 로봇 등에서 영상 스캐닝을 위해 광 빔을 주사하는 광원으로 사용될 수 있다. 다양한 분야에서 응용을 위한 광 위상 배열 안테나의 바람직한 성능은 크기가 작고, 광 빔 발산 효율이 높고, 선명한 빔을 형성하고, 빔 스캐닝 범위가 넓어야 한다. 이러한 여러 가지 요구 성능 중에서 소형화를 달성하기 위해서는 반도체 소재를 기반으로 하는 광 위상 배열 안테나 구성이 필요하다. 또한, 광 빔의 발산 효율, 선명도, 그리고 스캐닝의 성능들은 광파를 발산하는 광 발산기의 구조에 크게 의존되므로, 본 발명에서는 광 발산기에 대한 구체적인 구조를 반도체 소재를 기반으로 제안하고자 한다.The optical phased array antenna may be used as a light source for scanning an optical beam for image scanning in a driverless vehicle, a robot, and the like. The desirable performance of an optical phased array antenna for applications in various fields should be small in size, high in light beam divergence efficiency, forming a clear beam, and having a wide beam scanning range. To achieve miniaturization among these various required performances, an optical phased array antenna based on semiconductor materials is required. In addition, since the divergence efficiency, clarity, and scanning performance of the light beam are highly dependent on the structure of the light emitter emitting light waves, the present invention proposes a specific structure for the light emitter based on the semiconductor material.
여기서 반도체 소재에는 실리콘, 화합물 소재 반도체뿐만 아니라 이들 소재의 광 소자 제작에 사용되는 실리콘 산화물, 실리콘 질화물 등의 절연체(dielectric) 소재와 금속 박막 소재들을 포함한다.The semiconductor material includes not only silicon and a compound material semiconductor, but also an insulator material such as silicon oxide and silicon nitride and metal thin film materials used to fabricate optical devices of these materials.
나노포토닉스 기반의 광 위상 배열 안테나에 대한 종래의 발명(US Patent Application 2014/0192394 A1)은 반도체 실리콘 소재를 기반으로 위상제어 광 소자를 MxM matrix(행렬) 형으로 집적한 광 위상 배열 안테나를 제안한 바 있다.Conventional invention for nanophotonics based optical phased array antenna (US Patent Application 2014/0192394 A1) proposed an optical phased array antenna in which a phase controlled optical element is integrated in an MxM matrix type based on a semiconductor silicon material. have.
종래의 발명에서, 위상 배열 안테나에서 광파를 발산하는 광 발산기(상기 발명 내용에서 antenna element에 해당)는 격자 구조로 구성되었으나, 광 발산기의 배열을 matrix 형으로 배치하고, 각 단위 광 발산기 사이에 광 파워 분배선(directional coupler), 위상지연선(optical delay line)들이 배치되는 구조를 갖는다. 이와 같이, 여러 기능의 소자들이 하나의 단위 셀(unit cell) 내에 밀집됨으로 인하여, 핵심이 되는 광 발산기의 격자가 차지할 수 있는 공간이 작게 되고, 이 작은 공간에 들어가는 격자는 수 마이크로미터 규모로 작아져야만 한다. 따라서, 격자의 규모가 작아지면 광파의 발산효율이 저하되어 고성능의 빔을 얻기 어려운 문제가 발생된다.In the conventional invention, the light emitter for emitting light waves from the phased array antenna (corresponding to the antenna element in the present invention) has a lattice structure, but the array of light emitters is arranged in a matrix form, and each unit light emitter is arranged. Optical power distribution lines (directional couplers), optical delay lines (optical delay lines) are arranged between. As such, the functions of several functional elements are concentrated in one unit cell, so that the space occupied by the grating of the core light emitter is small, and the grating entering the small space is several micrometers in size. It must be small. Therefore, the smaller the size of the grating, the lower the divergence efficiency of the light waves, a problem that is difficult to obtain a high-performance beam.
본 연구실의 종전의 발명(PCT/KR2015/012199)에서는 광 발산기 부분에 충분한 공간을 제공할 수 있는 도 1과 같은 위상 배열 안테나를 제안하였다. 도 1에서 위상 배열 안테나를 구성하는 주요 소자들은 크게 광원(100)(light source), 광 파워 분배기(101-1, 101-2)(power distributor), 위상 제어기(102)(phase controller), 광 발산기(104)(radiator)로 구성되어 있다. 이들 구성 소자들 간에는 광 도파로(106)로 연결되어 있다. 또한, 위상 제어기(102)와 광 발산기(104) 사이에도 광 도파로(106)로 연결되어 있으며, 이 연결 도파로는 밀집도가 높아 도파로 간의 커플링(coupling)이 발생될 수 있어 그 배치가 중요하므로, 위상 공급선(103)(phase-feeding line)으로 구분한다.The previous invention of the present lab (PCT / KR2015 / 012199) proposed a phased array antenna as shown in FIG. 1 which can provide sufficient space in the light emitter portion. The main elements constituting the phased array antenna in FIG. 1 are largely a light source 100, a light power distributor 101-1, 101-2, a power distributor, a phase controller 102, and a light. It consists of an emitter 104 (radiator). These components are connected by an optical waveguide 106. In addition, the optical waveguide 106 is also connected between the phase controller 102 and the light emitter 104. Since the connection waveguides have high density, coupling between the waveguides can occur, so the arrangement is important. , Phase-feeding line (103).
도 1의 위상 배열에서는 광 발산기(104)의 길이방향으로 충분한 공간을 확보하기 위하여 1xM 발산기 어레이(105) 밖에 광 파워 분배기(101-1, 101-2), 위상 제어기(102), 위상 공급선(103)들을 배치한 특징을 갖고 있다. 이와 같이, 종전의 발명은 1xM 발산기 어레이 N 개를 상하로 독립적으로 배치하여 (1xM)xN 위상 배열을 구현함으로써, 2차원(2D) 빔 스캐닝 기능을 달성하면서도, 이웃하는 1xM 어레이 사이에 충분한 공간을 확보할 수 있음을 제시하였다.In the phase arrangement of FIG. 1, the optical power divider 101-1, 101-2, phase controller 102, and phase outside the 1 × M diverter array 105 to ensure sufficient space in the longitudinal direction of the light diverter 104. The supply line 103 is arrange | positioned. As such, the prior invention implements a (1xM) xN phased array by arranging N 1xM diverter arrays up and down independently to achieve a two-dimensional (2D) beam scanning function while providing sufficient space between neighboring 1xM arrays. Proposed that it can be secured.
따라서 본 발명에서는 상기 (1xM)xN 위상 배열에 적합하게 격자 구조의 길이방향으로 공간을 충분히 활용한 광 발산기 구조를 제안한다.Accordingly, the present invention proposes a light diverter structure that makes full use of the space in the longitudinal direction of the lattice structure suitable for the (1xM) xN phase arrangement.
본 발명은 세부 격자 구조로써, 적절한 수준의 광 방사, 위상정합 빔의 성능을 확보하고자 한다.The present invention is a detailed grating structure, to ensure the performance of the appropriate level of light emission, phase matching beam.
또한, 본 발명은 양방향 광파 입력 방식으로부터, 광 발산기의 출력 광파가 방사되는 각도의 범위를 넓히며, 궁극적으로 위상 배열로 얻어지는 위상정합 빔의 스캐닝 범위를 넓히고자 한다.In addition, the present invention seeks to widen the range of angles at which the output light waves of the light emitters are radiated from the bidirectional light wave input method, and ultimately to widen the scanning range of the phase matched beams obtained in the phase array.
본 발명의 일실시예에 따른, 광 위상 배열 안테나를 구성하는 광 발산기 소자는 반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로; 및 상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자를 포함하고, 상기 광 발산기 소자는 입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사한다.According to an embodiment of the present invention, an optical diverter element constituting an optical phased array antenna includes: an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material; And a grating periodically formed above or below the optical waveguide, wherein the light diverter element receives an input light wave in one direction of the optical waveguide and the grating, and spaces the output light wave using scattering from the grating. To emit.
상기 광 발산기 소자는 상기 출력 광파가 방사되는 종방향 각도 범위를 넓히기 위해, 상기 입력 광파를 상기 광 도파로와 상기 격자의 양방향으로 입사하여, 상기 격자로부터의 산란을 이용하여 상기 출력 광파를 공간으로 방사할 수 있다.The light diverter element injects the input light wave in both directions of the optical waveguide and the grating to widen the longitudinal angular range from which the output light wave is radiated, and scatters the output light wave into space by using scattering from the grating. It can radiate.
상기 광 발산기 소자의 기하학적인 변수들-상기 기하학적인 변수들은 상기 도파로 코어의 너비, 상기 도파로 코어의 두께, 상기 격자의 너비, 상기 격자의 주기 및 상기 격자의 깊이를 포함함- 중 적어도 어느 하나의 규모는 상기 입력 광파의 파장의 절반인 회절한계 이내의 값 또는 상기 회절한계에 대해 미리 설정된 범위만큼 근접한 값을 가질 수 있다.At least one of geometric variables of the light emitter element, the geometric variables including the width of the waveguide core, the thickness of the waveguide core, the width of the grating, the period of the grating and the depth of the grating. The magnitude of may be a value within a diffraction limit that is half of the wavelength of the input light wave or close to a preset range for the diffraction limit.
상기 도파로 코어는 실리콘으로 형성될 수 있다.The waveguide core may be formed of silicon.
상기 도파로 코어가 실리콘으로 형성되는 경우, 상기 입력 광파의 자유공간 파장
Figure PCTKR2015012953-appb-I000001
은
Figure PCTKR2015012953-appb-I000002
범위를 가질 수 있다.When the waveguide core is formed of silicon, the free space wavelength of the input light wave
Figure PCTKR2015012953-appb-I000001
silver
Figure PCTKR2015012953-appb-I000002
It can have a range.
상기 격자의 너비 Wg는 상기 입력 광파의 자유공간 파장
Figure PCTKR2015012953-appb-I000003
대비
Figure PCTKR2015012953-appb-I000004
범위를 가질 수 있다.The width Wg of the grating is the free space wavelength of the input light wave
Figure PCTKR2015012953-appb-I000003
prepare
Figure PCTKR2015012953-appb-I000004
It can have a range.
상기 격자의 깊이는 상기 출력 광파가 방사되는 종방향 분포를 제어하기 위하여 조절될 수 있다.The depth of the grating can be adjusted to control the longitudinal distribution in which the output light waves are emitted.
상기 격자의 주기는 상기 출력 광파가 방사되는 종방향 방사각을 제어하기 위하여 조절될 수 있다.The period of the grating can be adjusted to control the longitudinal radiation angle at which the output light wave is emitted.
상기 격자의 너비는 상기 출력 광파가 방사되는 횡방향 방사 각도 범위를 제어하기 위하여 조절될 수 있다.The width of the grating can be adjusted to control the range of lateral radiation angles at which the output light waves are emitted.
본 발명의 일실시예에 따른, 반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로 및 상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자를 포함하여, 입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사하는 광 발산기 소자로 구성되는 광 발산기 어레이는 복수 개의 광 발산기 소자들의 어레이로 생성되고, 상기 복수 개의 광 발산기 소자들의 개수는 상기 복수 개의 광 발산기 소자들 각각으로부터 방사되는 출력 광파의 위상간섭으로 형성되는 위상정합 빔의 횡방향 빔 발산각을 제어하기 위하여 조절되며, 상기 복수 개의 광 발산기 소자들 각각에 포함되는 상기 격자의 주기의 개수는 상기 복수 개의 광 발산기 소자들 각각으로부터 방사되는 출력 광파의 위상간섭으로 형성되는 위상정합 빔의 종방향 빔 발산각을 제어하기 위하여 조절된다.According to an embodiment of the present invention, an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material, and a grating periodically formed above or below the optical waveguide, the input light wave is one direction of the optical waveguide and the grating. And a light emitter array composed of light emitter elements which emit light into the space using scattering from the grating, the light emitter array being generated as an array of a plurality of light emitter elements, the plurality of light emitter elements The number of beams is adjusted to control the lateral beam divergence angle of the phase matching beam formed by the phase interference of the output light waves emitted from each of the plurality of light diverter elements, and included in each of the plurality of light diverter elements. The number of periods of the grating being radiated from each of the plurality of light emitter elements It is adjusted so as to control the longitudinal beam divergence angle of a coherent beam is formed in a phase of the interference wave power.
본 발명의 일실시예에 따른, 반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로 및 상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자를 포함하여, 입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사하는 광 발산기 소자로 구성되는 광 위상 배열 안테나는 복수 개의 광 발산기 소자들의 어레이로 생성되고, 상기 복수 개의 광 발산기 소자들이 균등한 위상차를 갖도록 커지거나 작아지는 위상을 상기 복수 개의 광 발산기 소자들 각각으로 공급하며, 상기 복수 개의 광 발산기 소자들의 위상 배열에 의한 위상정합 빔을 상기 공간 상에서 횡방향으로 빔 스티어링(steering)한다.According to an embodiment of the present invention, an optical waveguide including a waveguide core and a waveguide clad using a semiconductor material, and a grating periodically formed above or below the optical waveguide, the input light wave is one direction of the optical waveguide and the grating. The optical phased array antenna, which is composed of a light emitter element which is incident on the light and emits an output light wave into space using scattering from the grating, is generated as an array of a plurality of light emitter elements, and the plurality of light emitter elements Supplying a phase that increases or decreases so as to have an equal phase difference to each of the plurality of light emitter elements, and performs beam steering in a transverse direction in the space with a phase matching beam by the phase arrangement of the plurality of light emitter elements. steering.
본 발명은 세부 격자 구조로써, 적절한 수준의 광 방사, 위상정합 빔의 성능을 확보할 수 있다.The present invention is a detailed grating structure, it is possible to ensure the performance of the appropriate level of light emission, phase matching beam.
또한, 본 발명은 양방향 광파 입력 방식으로부터, 광 발산기의 출력 광파가 방사되는 각도의 범위를 넓힐 수 있으며, 궁극적으로 위상 배열로 얻어지는 위상정합 빔의 스캐닝 범위를 넓힐 수 있는 효과가 있다.Further, the present invention can widen the range of angles at which the output light waves of the light emitters are radiated from the bidirectional light wave input method, and ultimately, widen the scanning range of the phase matched beams obtained in the phased array.
도 1은 종전의 발명에서 제안한 광 위상 배열 안테나를 구성하는 주요 소자들을 나타내는 개략도이다.1 is a schematic diagram showing the main elements constituting the optical phased array antenna proposed in the previous invention.
도 2는 본 발명의 일실시예에 따른 광 발산기의 기본구조를 나타낸 개략도이다.Figure 2 is a schematic diagram showing the basic structure of the light emitter according to an embodiment of the present invention.
도 3은 본 별명의 일실시예에 따른 단일 격자 구조로부터 방사되는 회절패턴이다.3 is a diffraction pattern emitted from a single grating structure according to one embodiment of the present nickname.
도 4는 본 별명의 일실시예에 따른 단일 격자 구조에서 격자주기가 방사각도에 미치는 영향을 보여주는 결과이다.4 is a result showing the effect of the lattice period on the radiation angle in a single lattice structure according to an embodiment of the present invention.
도 5는 본 별명의 일실시예에 따른 단일 격자 구조에서 방사되는 원거리장 패턴의 범위를 보여주는 결과이다.5 is a result showing the range of the far-field pattern emitted in a single lattice structure according to an embodiment of the present nickname.
도 6은 본 별명의 일실시예에 따른 격자 구조 발산기 어레이에서 발산된 위상정합 빔의 형태를 보여주는 결과이다.FIG. 6 shows the shape of a phase-matching beam emitted from a grating structure diverger array according to an embodiment of the present invention.
도 7은 본 별명의 일실시예에 따른 격자 구조 발산기 어레이에서 발산기 내 격자주기의 개수 Ng의 변화에 따른 위상정합 빔 형태의 변화를 보여주는 시뮬레이션 결과이다.FIG. 7 is a simulation result illustrating a change in the shape of a phase-matching beam according to a change in the number Ng of grating periods in an emanator in a grating structure emanator array according to an embodiment of the present invention.
도 8은 본 별명의 일실시예에 따른 격자 구조의 위상 배열에서 위상제어에 의한 위상정합 빔의 steering 기능을 보여주는 결과이다.FIG. 8 is a diagram illustrating a steering function of a phase matching beam by phase control in a phase arrangement of a lattice structure according to an embodiment of the present disclosure.
도 9는 본 별명의 일실시예에 따른 격자 구조에서 입력 광파의 양방향 입사에 따른 방사되는 출력 광파의 종방향 범위의 확장을 보여주는 개략도이다.9 is a schematic diagram showing the extension of the longitudinal range of the output light wave emitted by bidirectional incidence of the input light wave in the grating structure according to the embodiment of the present nickname.
이하, 첨부된 도면을 참조하면서 본 발명의 실시예들에 따른 격자구조 발산기에 대해 상세히 설명하기로 한다. 본 발명의 하기의 실시예들은 본 발명을 구체화하기 위한 것일 뿐 본 발명의 권리 범위를 제한하거나 한정하는 것이 아님은 물론이다. 본 발명의 상세한 설명 및 실시예들로부터 본 발명이 속하는 기술 분야의 전문가가 용이하게 유추할 수 있는 것은 본 발명의 권리 범위에 속하는 것으로 해석된다.Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the lattice structure diverger according to embodiments of the present invention. The following examples of the present invention are intended to embody the present invention, but not to limit or limit the scope of the present invention. From the detailed description and the embodiments of the present invention, those skilled in the art to which the present invention pertains can easily be interpreted as falling within the scope of the present invention.
도 2는 본 발명의 일실시예에 따른 광 발산기의 기본구조를 나타낸 개략도이다. 구체적으로, 도 2의 (a)는 광 발산기를 나타낸 측면 단면도이고, (b)는 광 발산기를 나타낸 조감도이다.Figure 2 is a schematic diagram showing the basic structure of the light emitter according to an embodiment of the present invention. Specifically, Figure 2 (a) is a side cross-sectional view showing a light emitter, (b) is a bird's eye view showing the light emitter.
도 2를 참조하면, 격자 구조는 일반적으로 광 도파로 코어(200)의 끝 부분에 위치하며, 광 도파로 코어(200)의 상부 또는 하부에 형성한다. 격자 구조는 광 도파로 코어(200) 부분에 한하지 않고, 코어(200)의 주위에도 형성할 수 있다. 도파로는 일반적인 반도체 또는 절연체 소재가 사용될 수 있으며, rib형, channel형 등의 도파로 구조로 제작 될 수 있다. 이 때, 도면에는 주요 설계변수를 제시하기 위하여, channel형 광 도파로를 예로 들어 도파로의 코어 부분만 도시되었고, 도파로 코어(200)의 상부에 형성된 격자가 도시되어 있다.Referring to FIG. 2, the grating structure is generally located at the end of the optical waveguide core 200 and is formed on the upper or lower portion of the optical waveguide core 200. The lattice structure is not limited to the optical waveguide core 200 portion, but can also be formed around the core 200. The waveguide may be a general semiconductor or insulator material, and may be manufactured in a waveguide structure such as rib type or channel type. In this case, only the core portion of the waveguide is shown as an example of the channel type optical waveguide, and a grating formed on the top of the waveguide core 200 is illustrated in order to present major design variables.
입력 광파(202)가 광 도파로 코어(200)를 통하여 입력되면, 격자(201) 부분에서 산란 (scattering)이 일어나 외부 공간으로 비교적 넓은 범위에 걸쳐 펼쳐진 회절패턴의 출력 광파(203)가 방사(radiation)된다.When the input light wave 202 is input through the optical waveguide core 200, scattering occurs in a portion of the grating 201 so that the output light wave 203 of the diffraction pattern spread over a relatively wide range to the external space is radiated. )do.
여기서, 입력 광파(202)의 파장은 광 도파로(200)에서 광 손실(optical loss)이 적은 파장대역 중에서 선택될 수 있다. 예를 들어, 광 도파로 코어(200)가 실리콘인 경우, 입력 광파(202)의 파장은
Figure PCTKR2015012953-appb-I000005
의 파장(자유공간에서 파장) 대역이 바람직하다.In this case, the wavelength of the input light wave 202 may be selected from a wavelength band having a low optical loss in the optical waveguide 200. For example, when the optical waveguide core 200 is silicon, the wavelength of the input light wave 202 is
Figure PCTKR2015012953-appb-I000005
The wavelength (wavelength in free space) band of is preferable.
광 발산기 소자에서 주요 설계 변수들(기하학적인 변수들)은 격자의 주기(
Figure PCTKR2015012953-appb-I000006
), 단위 격자의 골(205)(valley) 부분의 너비(
Figure PCTKR2015012953-appb-I000007
), 단위 격자의 언덕(206)(hill) 부분의 너비(
Figure PCTKR2015012953-appb-I000008
), 격자의 주기의 개수(Ng), 격자의 길이(
Figure PCTKR2015012953-appb-I000009
), 격자의 깊이(격자의 골의 깊이)(Hs), 격자 부분 도파로 코어(200-1)의 두께(Hc), 도파로 코어(200)에서 격자의 너비(Wg), 및 단위 발산기 사이 간격(pitch)(Dr) 등을 포함할 수 있다.The main design variables (geometric variables) in the light emitter device are the period of the grating
Figure PCTKR2015012953-appb-I000006
), The width of the valley 205 portion of the unit grid (
Figure PCTKR2015012953-appb-I000007
), The width of the hill portion of the unit grid (206) (
Figure PCTKR2015012953-appb-I000008
), The number of cycles in the grid (Ng), the length of the grid (
Figure PCTKR2015012953-appb-I000009
), The depth of the grating (depth of the valleys of the lattice) (Hs), the thickness (Hc) of the grating partial waveguide core 200-1, the width of the grating (Wg) in the waveguide core 200, and the spacing between the unit diverters (Pitch) (Dr) and the like.
본 발명에서는 광파 방사효율, 방사 각도의 범위, 위상 배열로 형성된 위상정합(phase-matched) 빔의 형태와 스캐닝 각도 범위 등이 적절한 수준을 얻을 수 있는 세부 격자 구조를 제시한다.The present invention proposes a detailed grating structure in which light wave radiation efficiency, a range of radiation angles, a shape of a phase-matched beam formed in a phased array, a scanning angle range, and the like can be obtained at an appropriate level.
또한, 도면에는, 입력 광파(202)가 하나의 방향(좌측에서 우측으로)으로만 입사되는 것으로 도시되었으나, 이에 제한되거나 한정되지 않고, 스캐닝 각도 범위를 보다 넓힐 수 있는 방안으로 격자의 양방향으로 입력 광파를 입사하는 안테나 구조도 제안될 수 있다. 이에 대한 상세한 설명은 도 9를 참조하여 기재하기로 한다.In addition, although the input light wave 202 is illustrated as being incident only in one direction (from left to right) in the drawing, the input light wave 202 is not limited thereto, but is input in both directions of the grating in order to widen the scanning angle range. An antenna structure for injecting light waves may also be proposed. Detailed description thereof will be described with reference to FIG. 9.
격자 구조로부터 방사되는 출력 광파(203)의 원거리장의 방사각은 회절(diffraction) 원리에 의하여 수학식 1을 활용하여 설계될 수 있다.The radiation angle of the far field of the output light wave 203 radiated from the grating structure may be designed by using Equation 1 by the diffraction principle.
<수학식 1><Equation 1>
Figure PCTKR2015012953-appb-I000010
Figure PCTKR2015012953-appb-I000010
수학식 1에서,
Figure PCTKR2015012953-appb-I000011
는 입력 광파(202)의 자유공간에서 중심 파장,
Figure PCTKR2015012953-appb-I000012
는 격자의 주기, neff는 격자를 포함하는 광 도파로(코어와 클래드를 포함한 전체 도파로)의 유효 귤절률(effective index), nc는 격자가 형성된 광 도파로 코어 위를 덮고 있는 클래드 (clad)의 굴절률, 그리고
Figure PCTKR2015012953-appb-I000013
는 주기적인 격자로부터 산란된 광파의 회절로 형성된 회절패턴 중에서 빛의 세기가 가장 큰 중심에 해당되는 방사 각도(예컨대, 격자표면의 법선(normal)방향으로부터의 각도)를 나타낸다.In Equation 1,
Figure PCTKR2015012953-appb-I000011
Is the center wavelength in the free space of the input light wave 202,
Figure PCTKR2015012953-appb-I000012
Is the period of the grating, n eff is the effective index of the optical waveguide (the entire waveguide including the core and clad) containing the grating, n c is the cladding of the cladding over the core Refractive index, and
Figure PCTKR2015012953-appb-I000013
Represents a radiation angle (for example, an angle from the normal direction of the grating surface) of the diffraction pattern formed by diffraction of light waves scattered from the periodic grating, which corresponds to the center of the light intensity.
여기서, 유효 굴절률 neff는 광 도파로의 소재와 광파의 파장에 따른 굴절률 (refractive index)을 기반으로 하여 광 도파로의 구조에 따라 정해진다. 또한, 클래드의 굴절률은 격자가 자유공간에 노출되어 있을 경우에는 nc=1로 나타낼 수 있다. 이러한 수식은 고전적인 회절원리에 기반을 두고 있으나, 격자의 주기, 광 도파로 코어의 너비와 두께 등의 기하학적인 규모가 회절한계(diffraction limit) 이하인 경우, 즉, 입력 광파(202)의 파장의 절반(
Figure PCTKR2015012953-appb-I000014
/2)에 가깝거나 이보다 작을 경우에는 고전적인 회절원리로써는 제대로 묘사하기 어려운 점이 있다. 따라서, 본 발명은 나노포토닉스 영역에 포함되는 작은 규모의 영역에서, 일반적으로 수치적 시뮬레이션(numerical simulation)을 통하여 빔의 방사특성을 해석할 수 있다.The effective refractive index n eff is determined according to the structure of the optical waveguide based on the material of the optical waveguide and the refractive index according to the wavelength of the optical waveguide. In addition, the refractive index of the clad may be represented by n c = 1 when the grating is exposed to free space. This equation is based on the classical diffraction principle, but when the geometric scale, such as the period of the grating, the width and thickness of the optical waveguide core, is below the diffraction limit, i.e., half of the wavelength of the input light wave 202 (
Figure PCTKR2015012953-appb-I000014
If it is close to or smaller than / 2), the classical diffraction principle is difficult to describe properly. Therefore, the present invention can generally analyze the radiation characteristics of the beam through numerical simulation in a small region included in the nanophotonics region.
도 3은 본 별명의 일실시예에 따른 단일 격자 구조로부터 방사되는 회절패턴이다. 구체적으로, 도 3의 (a) 및 (c)는 격자 골의 깊이를 달리한 두 가지 격자 구조에 대한 설계변수 들의 값이며, (b)와 (d)는 해당 격자구조로부터 방사되는 근접장(near-field) 패턴의 시뮬레이션 결과이다(예컨대, (b)와 (d)는 해당 격자에 대해 FDTD(finite-difference time-domain)로 시뮬레이션 한 방사특성임). 즉, 도 3은 격자의 길이방향인 종방향으로 방사되는 출력 광파의 분포를 제어할 수 있는 주요변수의 영향을 보여주는 예이다. 3 is a diffraction pattern emitted from a single grating structure according to one embodiment of the present nickname. Specifically, (a) and (c) of FIG. 3 are values of design variables for two lattice structures having different depths of lattice valleys, and (b) and (d) are near fields radiated from the lattice structure. -field) pattern (for example, (b) and (d) are radiation characteristics simulated with a finite-difference time-domain (FDTD) for the grid). That is, Figure 3 is an example showing the influence of the main variables that can control the distribution of the output light wave emitted in the longitudinal direction of the grating.
(b)와 (d)의 방사특성은 격자의 종단면(도 2의 (a)에서 X-Y면) 상에서 광파의 전기장(electric field)의 근접장 (near-field)이며, field의 강도를 색상으로 나타낸 것이다. field는 (b)와 (d)에 도시된 바와 같이 종방향으로 여러 갈래로 나눠지며, 이는 산란의 정도가 격자 요철에 따라 다른 데서 나오는 현상이다. 전반적인 field의 강도는 격자의 길이방향으로 나아 갈수록 약해질 수 있다.The radiation characteristics of (b) and (d) are the near-field of the electric field of light waves on the longitudinal section of the grating (XY plane in Fig. 2 (a)), and the intensity of the field is expressed in color. . The field is divided into several branches in the longitudinal direction as shown in (b) and (d), which is a phenomenon in which the degree of scattering is different depending on lattice irregularities. The overall field strength may weaken further along the length of the grating.
(b)의 결과에서는 80% 이상의 field가 격자의 전체길이 15 (격자주기 Ng=24) 중 5
Figure PCTKR2015012953-appb-I000015
(Ng=8) 이내의 앞부분에서 방사되나, (d)의 결과에서는 격자의 뒷부분까지 상당한 field가 분포되어 있다. 이러한 차이는 격자 골의 깊이 Hs의 차이에서 나오는 것이다. 즉, 격자 골의 깊이가 깊으면, 산란효과가 커져 격자의 앞부분에 방사 field가 집중되며, 깊이가 얕으면 산란효과가 적어져 격자의 뒷부분까지 방사 field가 분산될 수 있다.In the result of (b), more than 80% of the fields show 5 out of the total length of the grid 15 (lattice period Ng = 24).
Figure PCTKR2015012953-appb-I000015
The radiation is from the front within (Ng = 8), but in the result of (d) there is a significant field distribution up to the back of the grid. This difference comes from the difference in the depth Hs of the lattice valleys. That is, when the depth of the grating valleys is deep, the scattering effect is increased and the radiation field is concentrated at the front part of the grating, and when the depth is shallow, the scattering effect is small and the radiation field may be dispersed to the rear part of the grating.
여기서, field가 격자의 앞부분에 집중이 되면 전체 방사효율이 떨어지므로, 전체 효율을 높이려면, (d)와 같이 격자의 길이방향으로 충분한 거리까지 산란이 이루어지도록 하는 것이 바람직하다.In this case, when the field is concentrated at the front of the grating, the overall radiation efficiency decreases. Therefore, in order to increase the overall efficiency, it is preferable that scattering is performed to a sufficient distance in the longitudinal direction of the grating as shown in (d).
방사 field의 종방향 분포는 격자 골의 깊이 주된 영향을 받으나, 광파의 파장, 광 도파로 코어의 두께, 격자의 너비 등에도 영향을 받을 수 있다. 이러한 변수들의 영향을 고려하면, (a)와 (c)에서 예시한 변수들의 값에 가까운 범위에서는 대략적으로 광 도파로 코어의 두께 대비 격자 골의 깊이의 상대적 비가 1/4이상인 경우, 출력 광파의 전기장의 80% 이상이 격자의 8주기 이내에서 공간으로 방사될 수 있으며, 광 도파로 코어의 두께 대비 격자 골의 깊이의 상대적 비가 1/4 이하인 경우, 출력 광파의 전기장의 80% 이상이 격자의 5주기 내지 8주기 이상의 범위까지 공간으로 방사될 수 있다.The longitudinal distribution of the radiation field is mainly affected by the depth of the grating valleys, but can also be influenced by the wavelength of the light waves, the thickness of the optical waveguide core and the width of the grating. Considering the influence of these variables, the electric field of the output light wave is roughly in the range close to the values of the parameters illustrated in (a) and (c) when the relative ratio of the grating valley depth to the thickness of the optical waveguide core is approximately 1/4 or more. More than 80% of the grating can be radiated into the space within 8 cycles of the grating, and if the relative ratio of the grating valley depth to the thickness of the optical waveguide core is less than 1/4, then more than 80% of the electric field of the output lightwave is 5 cycles of the grating Up to 8 cycles or more.
도 4는 본 별명의 일실시예에 따른 단일 격자 구조에서 격자주기가 방사각도에 미치는 영향을 보여주는 결과이다. 구체적으로, 도 4의 (a)는 설계변수들의 값이며, (b)는 (a)의 설계변수로 고정시켜두고 격자주기 변화
Figure PCTKR2015012953-appb-I000016
에 따른 원거리장(far-field)의 종방향 방사각(
Figure PCTKR2015012953-appb-I000017
에 해당) 변화를 보여주는 시뮬레이션 결과이다.4 is a result showing the effect of the lattice period on the radiation angle in a single lattice structure according to an embodiment of the present invention. Specifically, (a) of FIG. 4 is a value of design variables, and (b) is fixed to a design variable of (a) to change the lattice period.
Figure PCTKR2015012953-appb-I000016
Longitudinal radial angle of the far-field
Figure PCTKR2015012953-appb-I000017
This is a simulation result showing the change.
도 4를 참조하면, (b)에서 격자주기
Figure PCTKR2015012953-appb-I000018
의 작은 변화로 방사각을 넓은 범위로 변화시킬 수 있음을 확인할 수 있다. 또한, (a)의 구조에서 유효 굴절률 neff은 2.8 정도이며 격자의 주기에는 크게 영향을 받지 않는다. 이 때, 유효 굴절률은 격자가 형성된 광 도파로 코어의 너비 Wg에 민감하게 변하며, (a)의 구조에서 광 도파로 코어의 반도체 소재의 굴절률이 3.5 이고, 코어의 너비가 0.3,
Figure PCTKR2015012953-appb-I000019
범위에서 있을 경우에 격자가 형성된 광 도파로의 유효 굴절률은 2.5 <neff<3.0 범위 내에 든다.4, the lattice period in (b)
Figure PCTKR2015012953-appb-I000018
It can be seen that a small change in can change the radiation angle over a wide range. In addition, in the structure of (a), the effective refractive index n eff is about 2.8 and is not significantly affected by the period of the lattice. At this time, the effective refractive index is sensitive to the width Wg of the optical waveguide core in which the grating is formed, the refractive index of the semiconductor material of the optical waveguide core is 3.5, the width of the core is 0.3,
Figure PCTKR2015012953-appb-I000019
When in the range, the effective refractive index of the grating-formed optical waveguide is within the range of 2.5 <n eff <3.0.
수학식 1을 참조하면, 방사각
Figure PCTKR2015012953-appb-I000020
는 자유공간 파장 대비 격자의 주기의 상대적인 비
Figure PCTKR2015012953-appb-I000021
/
Figure PCTKR2015012953-appb-I000022
값과 유효 굴절률 neff의 상대적 차이로 정해지는 경향이 있다. 이러한 경향을 고려하면, (a)에서 예시한 변수들의 값에 가까운 범위에서
Figure PCTKR2015012953-appb-I000023
/
Figure PCTKR2015012953-appb-I000024
값이 대략적으로
Figure PCTKR2015012953-appb-I000025
사이의 값으로 변화될 때, 종방향 방사각의 범위는 0도에서 60도 사이에서 변화될 수 있다.
Figure PCTKR2015012953-appb-I000026
/
Figure PCTKR2015012953-appb-I000027
값을 상기 범위보다 더 줄여 종방향 방사각의 범위를 60도 이상으로 더 크게 할 수는 있으나, 방사효율이 떨어져 활용성이 적게 된다.Referring to Equation 1, the radial angle
Figure PCTKR2015012953-appb-I000020
Is the relative ratio of the period of the grating to the free-space wavelength
Figure PCTKR2015012953-appb-I000021
Of
Figure PCTKR2015012953-appb-I000022
It tends to be determined by the relative difference between the value and the effective refractive index n eff . Considering this tendency, the range close to the values of the variables exemplified in (a)
Figure PCTKR2015012953-appb-I000023
Of
Figure PCTKR2015012953-appb-I000024
Approximate value
Figure PCTKR2015012953-appb-I000025
When varying between values, the range of longitudinal radiation angles can vary between 0 degrees and 60 degrees.
Figure PCTKR2015012953-appb-I000026
Of
Figure PCTKR2015012953-appb-I000027
Although the value can be made smaller than the above range, the longitudinal radiation angle range can be made larger than 60 degrees, but the radiation efficiency is lowered, resulting in less utility.
다음은 단일 발산기의 횡방향 발산 범위에 영향을 주는 변수들을 설명한다. 고전적인 Gaussian 빔 발산원리에 기반하면, 단일 발산기에서 발산되는 광파의 횡방향 각도범위
Figure PCTKR2015012953-appb-I000028
는 수학식 2로 나타낼 수 있다.The following describes the variables that affect the lateral divergence range of a single diverger. Based on the classical Gaussian beam divergence principle, the transverse angular range of light waves emitted by a single diverger
Figure PCTKR2015012953-appb-I000028
May be represented by Equation 2.
<수학식 2><Equation 2>
Figure PCTKR2015012953-appb-I000029
Figure PCTKR2015012953-appb-I000029
수학식 2에서 Wg는 Gaussian 빔 발산의 원점인 개구경의 크기에 해당되는 변수로써, 격자구조의 광 발산기에서는 격자의 너비 Wg가 될 수 있다.In Equation 2, Wg is a variable corresponding to the size of the aperture diameter, which is the origin of Gaussian beam divergence, and may be the width Wg of the lattice in the light diverter of the lattice structure.
수학식 2의 기본 수식에 의하면, 단일 격자 구조에서 방사되는 원거리장의 횡방향 범위는 주로 파장 대비 격자의 너비의 상대적인 비, 즉,
Figure PCTKR2015012953-appb-I000030
/Wg에 의해 결정되며, 격자의 상대적인 너비가 좁을 수록 원거리장의 횡방향 범위는 넓어질 수 있다. 수학식 2는 상기 변수들의 대략적인 관계만 나타내줄 뿐이며, 나노포토닉스 영역인 본 발명의 실시예의 구조에서 방사범위는 후술되는 도 5와 같이 수치해석적인 시뮬레이션으로 확인될 수 있다.According to the basic formula of Equation 2, the lateral range of the far field radiated in the single lattice structure is mainly a relative ratio of the width of the lattice to the wavelength, that is,
Figure PCTKR2015012953-appb-I000030
/ Wg, the narrower the relative width of the grid, the wider the lateral range of the far field. Equation 2 only shows the approximate relationship of the variables, the radiation range in the structure of the embodiment of the present invention, which is a nanophotonic region can be confirmed by numerical simulation as shown in FIG.
도 5는 본 별명의 일실시예에 따른 단일 격자 구조에서 방사되는 원거리장의 범위를 보여주는 결과이다. 구체적으로, 도 5의 (a)는 반구(hemisphere)의 공간좌표계를 나타내는 입체도이며, (b)는 반구 공간좌표계에서 방사범위를 평면 투영으로 나타낸 시뮬레이션 결과이다.5 is a result showing the range of the far field radiated in a single lattice structure according to an embodiment of the present nickname. Specifically, (a) of FIG. 5 is a three-dimensional view showing the spatial coordinate system of the hemisphere (b), (b) is a simulation result showing the radiation range in a planar projection in the hemisphere spatial coordinate system.
도 5를 참조하면, 도 5에 적용된 구조는 본 발명에서 횡방향 범위를 넓게 설계한 일실시예이며, Wg를 비롯한 주요 설계변수는 도 4의 (a)와 같다. 다만, 격자의 주기는
Figure PCTKR2015012953-appb-I000031
=620nm를 선택한 것이며, 이 주기에서 방사각은
Figure PCTKR2015012953-appb-I000032
=10.4도이다.Referring to FIG. 5, the structure applied to FIG. 5 is an embodiment in which the transverse range is widely designed in the present invention, and main design variables including Wg are the same as in FIG. 4A. However, the cycle of the grid
Figure PCTKR2015012953-appb-I000031
= 620 nm, and the emission angle in this period
Figure PCTKR2015012953-appb-I000032
= 10.4 degrees.
(a)의 구조에서 횡방향 범위를 결정하는 주요변수는
Figure PCTKR2015012953-appb-I000033
/Wg=3.1이다. 도 5의 (a)와 (b)에서 W(0도)-E(180도) 사이 방향은 격자의 횡방향(도 2에서 Z 방향)에 해당되고 N 방향은 격자의 법선방향(도 2에서 Y 방향, 수학식 1에서
Figure PCTKR2015012953-appb-I000034
=0도)에 해당된다. 도 5의 (a)의 예시 구조는 방사각이
Figure PCTKR2015012953-appb-I000035
=10.4이므로, 도 5의 (c)에서 방사패턴은 W(0도)-E(180도) 선 보다 90도 쪽으로 약간 치우쳐 있다. 상기 격자에서 방사되는 전기장(electric field) 분포는, (a)와 같이, 타원의 단면을 갖는 cone 형태에 가깝게 방사되며, (b)와 같이, 격자의 종방향 (90도-270도 사이 방향) 보다 횡방향 W(0도)-E(180도) 사이 방향)으로 더 넓게 방사된다. In the structure of (a), the main variable that determines the transverse range is
Figure PCTKR2015012953-appb-I000033
/Wg=3.1. In FIGS. 5A and 5B, the direction between W (0 degrees) and E (180 degrees) corresponds to the transverse direction of the lattice (Z in FIG. 2), and the N direction corresponds to the normal direction of the lattice (in FIG. 2). Y direction, in equation (1)
Figure PCTKR2015012953-appb-I000034
= 0 degrees). The example structure of FIG. 5 (a) has a radial angle
Figure PCTKR2015012953-appb-I000035
Since = 10.4, the radiation pattern in FIG. 5C is slightly biased toward 90 degrees from the W (0 degrees)-E (180 degrees) line. The electric field distribution radiated from the grating is radiated close to a cone shape having an elliptical cross section, as in (a), and as in (b), the longitudinal direction of the grating (between 90 and 270 degrees). More broadly in the transverse direction W (0 degrees) -E (180 degrees)).
(b)에서 W-N-E 방향으로 광 세기 (intensity)의 분포를 보면 수직방향 (N방향)에서 최대가 되며, 이 최대 세기의 1/e2 (최대 전기장의 1/e, 여기서 지수 e는 대략 2.72)로 떨어지는 범위까지의 방사각
Figure PCTKR2015012953-appb-I000036
를 넘어서고 있다. 이 결과는 본 발명의 실시예의 격자구조(
Figure PCTKR2015012953-appb-I000037
/Wg=3.1)로 위상 배열을 구성할 경우에 횡방향으로 beam-steering의 최대범위를
Figure PCTKR2015012953-appb-I000038
에 가깝게 넓힐 수 있음을 의미한다.In (b), the distribution of intensity in the WNE direction is the maximum in the vertical direction (N direction), and 1 / e 2 of this maximum intensity (1 / e of the maximum electric field, where the index e is approximately 2.72). Radial angle down to range
Figure PCTKR2015012953-appb-I000036
Is beyond. The result is the lattice structure of the embodiment of the present invention.
Figure PCTKR2015012953-appb-I000037
/Wg=3.1), the maximum range of beam-steering in the transverse direction
Figure PCTKR2015012953-appb-I000038
It means you can widen it closer to.
다음은 상기 광 발산기로 어레이를 구성할 경우에 위상정합 빔의 성능에 영향을 주는 변수들을 설명한다. 1xM 발산기 어레이에서 각 광 발산기에서 방사되는 출력 광파의 간섭에 의해 하나 또는 그 이상의 위상정합(phase-matched) 빔이 형성된다. 이 위상정합 빔의 횡방향 발산각(divergence angle)
Figure PCTKR2015012953-appb-I000039
은 고전적인 Gaussian 빔 발산원리에 기반하여 수학식 3으로 나타낼 수 있다.The following describes the variables that affect the performance of the phase-matching beam when configuring the array with the light diverger. One or more phase-matched beams are formed by the interference of the output light waves emitted from each light emitter in the 1 × M emitter array. Lateral divergence angle of this phase-matched beam
Figure PCTKR2015012953-appb-I000039
Can be represented by Equation 3 based on the classical Gaussian beam divergence principle.
<수학식 3><Equation 3>
Figure PCTKR2015012953-appb-I000040
Figure PCTKR2015012953-appb-I000040
수학식 3에서
Figure PCTKR2015012953-appb-I000041
는 Gaussian 빔 발산의 원점인 개구경의 크기를 어레이 전체 너비로 가정하여 정한 변수이다. 수학식 3의 기본 수식에 의하면, 위상정합 빔의 횡방향 발산각에 영향을 주는 주요 변수는 파장 대비 격자의 너비의 상대적인 비 (
Figure PCTKR2015012953-appb-I000042
/Wg)와 어레이 내 발산기의 개수 M이다. 특히, 수학식 3은 발산기의 개수 M이 늘어날수록 위상정합 빔의 횡방향 발산각 (divergence angle)
Figure PCTKR2015012953-appb-I000043
는 좁아지는 경향을 나타낸다. 수학식 3은 상기 변수들의 대략적인 관계만 나타내줄 뿐이며, 보다 구체적인 형태는 후술되는 도 6와 같이 수치해석적인 시뮬레이션으로 확인될 수 있다.In equation (3)
Figure PCTKR2015012953-appb-I000041
Is a variable determined by assuming that the size of the aperture diameter, which is the origin of Gaussian beam divergence, is the entire width of the array. According to the basic equation of Equation 3, the main variable affecting the lateral divergence angle of the phase matching beam is the relative ratio of the width of the grating to the wavelength (
Figure PCTKR2015012953-appb-I000042
/ Wg) and the number M of diverters in the array. In particular, Equation 3 indicates that the divergence angle of the phase-matching beam increases as the number M of diverters increases.
Figure PCTKR2015012953-appb-I000043
Indicates a tendency to narrow. Equation 3 only shows an approximate relationship between the variables, and more specific forms may be confirmed by numerical simulations as shown in FIG. 6.
도 6은 본 별명의 일실시예에 따른 격자 구조로 발산기 1xM 어레이를 구성할 경우에 어레이를 구성하는 발산기의 개수 M이 위상정합 빔의 행태에 미치는 영향을 구체적으로 보여주는 결과이다. 즉, 도 6은 본 발명의 일실시예에 따른 격자 구조로 1xM 어레이의 위상 배열을 구성하고, 각 발산기 간의 위상차이를
Figure PCTKR2015012953-appb-I000044
=0도로 고정시킨 경우에 위상 배열로부터 발산되는 위상정합 빔의 형태를 시뮬레이션 한 것이다.FIG. 6 illustrates the effect of the number M of diverters constituting the array on the behavior of the phase-matched beam when the diverger 1xM array is configured in a lattice structure according to an embodiment of the present invention. That is, FIG. 6 illustrates a phase arrangement of a 1xM array with a lattice structure according to an embodiment of the present invention, and shows the phase difference between each diverger.
Figure PCTKR2015012953-appb-I000044
It is a simulation of the shape of the phase-matching beam emitted from the phased array when fixed to 0 degrees.
구체적으로, 도 6의 (a)는 설계변수들의 값이며, (b)는 반구의 입체 공간좌표계에서 빔의 방사형태를 보여주는 개략도이며, (c)-(e)는 어레이 내 발산기의 개수 M에 따른 위상정합 빔 형태의 변화를 보여주는 시뮬레이션 결과이다.Specifically, (a) of Figure 6 is the value of the design variables, (b) is a schematic diagram showing the radiation pattern of the beam in the hemisphere three-dimensional spatial coordinate system, (c)-(e) is the number M of diverters in the array Simulation results show the change of phase-matched beam shape according to.
도 6을 참조하면, (a)에 예시한 발산기의 설계변수는 도 5에서 예시한 단위 설계변수를 적용한 것이다. 특히,
Figure PCTKR2015012953-appb-I000045
/Wg 변수는 도 5의 것과 동일하게 적용한 것이며, 격자의 개수는 Ng=24를 예로 든 것이다. (c)-(e)에서, 발산기의 개수 M이 8, 16, 32로 늘어날수록 위상정합 빔의 횡방향 발산각(divergence angle)
Figure PCTKR2015012953-appb-I000046
는 4.4도, 2.3도, 1.2도로 좁아짐을 확인할 수 있다. 상기 조건의 시뮬레이션에 의하면 발산기의 개수 M이 64 이상일 경우,
Figure PCTKR2015012953-appb-I000047
는 0.8도 수준 이하로 더 좁힐 수 있다.Referring to FIG. 6, the design variable of the emanator illustrated in (a) is a unit design variable illustrated in FIG. 5. Especially,
Figure PCTKR2015012953-appb-I000045
The / Wg variable is the same as that of FIG. 5, and the number of gratings is Ng = 24 as an example. In (c)-(e), as the number M of diverters increases to 8, 16, 32, the lateral divergence angle of the phase-matching beam
Figure PCTKR2015012953-appb-I000046
It can be seen that the narrowing is 4.4 degrees, 2.3 degrees, 1.2 degrees. According to the simulation of the above conditions, when the number of diverters M is 64 or more,
Figure PCTKR2015012953-appb-I000047
Can be further narrowed to below 0.8 degrees.
여기서 빔 발산각이 좁아진다는 것은 영상 스캐닝 (scanning)에서 분해능 (resolution)이 향상될 수 있는 의미를 갖는다. 따라서 횡방향 분해능의 조절은 발산기의 개수 M으로 조절할 수 있다. 이에 대비하여, 위상정합 빔의 종방향 발산각, 즉, 종방향 분해능의 조절은, 아래에서 설명할 도 7의 (c)-(e)와 같이, 어레이 내 발산기의 격자의 길이 Lg로 조절할 수 있다.In this case, narrowing of the beam divergence angle may mean that resolution may be improved in image scanning. Therefore, the lateral resolution can be controlled by the number M of diverters. In contrast, the adjustment of the longitudinal divergence angle of the phase-matching beam, that is, the longitudinal resolution, is controlled by the length Lg of the grating of the diverter in the array, as shown in FIGS. 7 (c)-(e) described below. Can be.
다음은 상기 발산기로 어레이를 구성할 경우에 위상정합 빔의 종방향 발산각에 영향을 주는 변수들을 설명한다. 위상정합 빔의 종방향 발산각
Figure PCTKR2015012953-appb-I000048
는 고전적인 Gaussian 빔 발산원리에 기반하여, 수학식 4로 나타낼 수 있다.The following describes the variables that affect the longitudinal divergence angle of the phase-matching beam when the array is constructed with the diverter. Longitudinal divergence angle of phase match beam
Figure PCTKR2015012953-appb-I000048
Can be expressed by Equation 4 based on the classical Gaussian beam divergence principle.
<수학식 4><Equation 4>
Figure PCTKR2015012953-appb-I000049
Figure PCTKR2015012953-appb-I000049
수학식 4는 수학식 2와 유사한 식으로, Gaussian 빔 발산의 원점인 개구경의 종방향의 크기, 즉, Lg에 위상정합 빔의 종방향 발산각이 정해진다고 가정한 것이다. 수학식 4의 기본 수식에 의하면, 단일 격자 구조에서 방사되는 far-field 원거리장의 횡방향 범위는 주로 파장 대비 격자의 너비의 상대적인 비, 즉,
Figure PCTKR2015012953-appb-I000050
/Lg에 의해 결정되며, 격자의 길이 Lg가 길수록, 즉, 파장 대비 상대적 비
Figure PCTKR2015012953-appb-I000051
/Lg가 작아질수록 격자정합 빔의 종방향 발산각
Figure PCTKR2015012953-appb-I000052
는 좁아질 수 있다. 격자의 길이는 곧
Figure PCTKR2015012953-appb-I000053
로 주어진다. 따라서 횡방향 분해능은 격자의 길이 Lg(또는 Ng)에 의해 조절될 수 있다. 수학식 4는 상기 변수들의 대략적인 관계만 나타내줄 뿐이며, 나노포토닉스 영역인 본 발명의 실시예의 구조에서 방사범위는 후술되는 도 7과 같이 수치해석적인 시뮬레이션으로 확인될 수 있다.Equation 4 is similar to Equation 2, and assumes that the longitudinal divergence angle of the phase-matching beam is determined in the longitudinal direction of the aperture diameter, ie, Lg, which is the origin of the Gaussian beam divergence. According to the basic equation of Equation 4, the lateral range of the far-field far field radiated in the single grating structure is mainly a relative ratio of the width of the grating to the wavelength, that is,
Figure PCTKR2015012953-appb-I000050
/ Lg, the longer the grating Lg, i.e. the relative ratio
Figure PCTKR2015012953-appb-I000051
As the / Lg decreases, the longitudinal divergence angle of the lattice match beam
Figure PCTKR2015012953-appb-I000052
Can be narrowed. The length of the grid
Figure PCTKR2015012953-appb-I000053
Is given by The lateral resolution can thus be controlled by the length Lg (or Ng) of the grating. Equation 4 only shows the approximate relationship of the variables, the radiation range in the structure of the embodiment of the present invention, which is a nanophotonic region can be confirmed by numerical simulation as shown in FIG.
도 7은 본 별명의 일실시예에 따른 격자 구조 발산기 어레이에서 격자주기의 개수 Ng의 변화에 따른 위상정합 빔의 위상정합 빔의 종방향 발산각
Figure PCTKR2015012953-appb-I000054
의 변화를 보여주는 시뮬레이션 결과이다. 도 7에 적용된 주요 설계변수는 도 6의 (a)의 설계변수와 동일하게 적용된 것이며, 광 발산기 어레이의 수는 M=8을 예로 든 것이다. 도 7의 예시에서, 격자주기의 개수 Ng를 16, 20, 24로 늘일 수록(격자의 길이 Lg를 길게 할수록) 위상정합 빔의 종방향 발산각
Figure PCTKR2015012953-appb-I000055
은 각각 6.3도, 5.2도, 3.3도로 좁아지며, 이에 따라 종방향 분해능은 향상될 수 있음을 확인할 수 있다.7 is a longitudinal divergence angle of a phase-matching beam of a phase-matching beam according to a change in the number of grid periods Ng in a grid-structure diverging array according to an embodiment of the present invention;
Figure PCTKR2015012953-appb-I000054
Simulation results showing the change of. The main design parameters applied to FIG. 7 are applied in the same manner as the design parameters of FIG. 6A, and the number of light emitter arrays is M = 8. In the example of FIG. 7, the longitudinal divergence angle of the phase-matching beam is increased as the number of grating periods Ng is increased to 16, 20, and 24 (as the length of the grid Lg is increased).
Figure PCTKR2015012953-appb-I000055
Are narrowed to 6.3 degrees, 5.2 degrees, and 3.3 degrees, respectively, and thus it can be seen that the longitudinal resolution can be improved.
도 8은 본 별명의 일실시예에 따른 격자 구조의 위상 배열에서 위상제어에 의한 위상정합 빔의 steering 기능을 보여주는 결과이다. 구체적으로, 도 8의 (a)는 설계변수들의 값이며, (b)는 반구의 입체 공간좌표계에서 빔 steering을 보여주는 개략도이며, (c)-(e)는 위상차
Figure PCTKR2015012953-appb-I000056
에 따른 위상정합 빔 steering을 보여주는 시뮬레이션 결과이다.FIG. 8 is a diagram illustrating a steering function of a phase matching beam by phase control in a phase arrangement of a lattice structure according to an embodiment of the present disclosure. Specifically, Figure 8 (a) is a value of the design variables, (b) is a schematic diagram showing the beam steering in the hemisphere three-dimensional spatial coordinate system, (c)-(e) is a phase difference
Figure PCTKR2015012953-appb-I000056
Simulation results showing the phase-matched beam steering according to
위상차가
Figure PCTKR2015012953-appb-I000057
=0도일 경우에, (c)와 같이, 중심 가까이, 즉, N 방향 가까이에 광 세기가 강한 위상정합 빔 1(801)이 형성되어 있다. (c)의 예에서는 W와 E 방향 가까이의 양쪽 외곽에 광 세기가 약한 두 개의 위상정합 빔 2(802)와 빔 3(803)도 형성되어 있다. 위상차를 0도에서 180도로 크게 하면, (c)와 (d)의 비교에서 알 수 있듯이, 빔 1(801)은 E 방향으로 이동하며, 빔 2(802)는 W 방향에서 중심(N방향) 쪽으로 이동한다. 이러한 이동 과정에서 빔1(801)의 광 세기는 점점 약화되고, W 방향 쪽의 빔 2(802)의 광 세기는 점점 강화된다. 위상차가 180도 이상으로 커지면, (e)와 같이, 빔 1(801)과 빔 2(802)는 E 방향으로 더 이동하고, field의 대부분은 빔 2(802)로 전이된다. 또한, W 방향 쪽에 빔 4(804)가 새로이 나타난다. 상기와 같이, 위상변조 과정에서 여러 개의 빔이 steering 될 수 있으며, 빔들 간에 광파 field의 전이가 되의 광 세기가 변화된다. 여러 개의 빔 중에서 광 세기가 가장 센 빔을 0th-order 빔, 그 외곽의 빔들을 high-order 빔으로 정의한다.Retardation
Figure PCTKR2015012953-appb-I000057
When = 0 degrees, as shown in (c), a phase matching beam 1 801 with strong light intensity is formed near the center, that is, near the N direction. In the example of (c), two phase matching beams 2802 and 3 beams 803 having weak light intensity are also formed on both outer edges near the W and E directions. If the phase difference is increased from 0 degrees to 180 degrees, as shown in the comparison between (c) and (d), beam 1 801 moves in the E direction, and beam 2 802 is centered in the W direction (N direction). To the side. In this movement, the light intensity of the beam 1 801 is gradually weakened, and the light intensity of the beam 2 802 toward the W direction is gradually enhanced. If the phase difference becomes larger than 180 degrees, as shown in (e), beam 1 801 and beam 2 802 move further in the E direction, and most of the field transitions to beam 2 802. Also, a new beam 4 804 appears in the W direction. As described above, a plurality of beams may be steered in the phase modulation process, and the light intensity of the transition of the light wave field is changed between the beams. Among the multiple beams, the beam with the strongest light intensity is defined as the 0 th -order beam and the outer beams are defined as the high-order beam.
도 8의 결과로부터 본 발명의 실시예의 위상 배열 구조에서 위상차이를
Figure PCTKR2015012953-appb-I000058
사이에서 변화시키고 0th-order 빔과 high-order 빔을 모두 사용할 경우에 beam-steering의 최대 횡방향 범위
Figure PCTKR2015012953-appb-I000059
는, (b)에 나타낸 바와 같이,
Figure PCTKR2015012953-appb-I000060
를 넘을 수 있다. 여기서 steering 각도가 너무 커지면 high-order 빔의 field가 너무 약화되는 문제가 있을 수 있다. 따라서, 광 빔의 세기를 적정 수준을 유지하기 위해서는 위상차이를
Figure PCTKR2015012953-appb-I000061
범위에서 변화시키고, 0th-order 빔 만을 사용하는 방식이 바람직하다. 이 방식에 따르면 beam-steering의 최대 횡방향 범위
Figure PCTKR2015012953-appb-I000062
'는 위상차이를
Figure PCTKR2015012953-appb-I000063
사이에서 변화시키고 0th-order 빔과 high-order 빔을 모두 사용하는 상기 방식의 최대 횡방향 범위
Figure PCTKR2015012953-appb-I000064
의 절반으로, 즉,
Figure PCTKR2015012953-appb-I000065
=
Figure PCTKR2015012953-appb-I000066
/2로 줄게 된다.From the results of FIG. 8, the phase difference in the phased array structure of the embodiment of the present invention
Figure PCTKR2015012953-appb-I000058
Maximum transverse range of beam-steering when changing between and using both 0 th -order and high-order beams
Figure PCTKR2015012953-appb-I000059
As shown in (b),
Figure PCTKR2015012953-appb-I000060
Can go beyond If the steering angle is too large, there may be a problem in that the field of the high-order beam is weakened too much. Therefore, in order to maintain an appropriate level of the intensity of the light beam,
Figure PCTKR2015012953-appb-I000061
It is preferable to change in the range and to use only 0 th- order beam. According to this method the maximum transverse range of the beam-steering
Figure PCTKR2015012953-appb-I000062
'Is the phase difference
Figure PCTKR2015012953-appb-I000063
Maximum transverse range of the scheme, varying between and using both 0 th -order beams and high-order beams
Figure PCTKR2015012953-appb-I000064
Half of that,
Figure PCTKR2015012953-appb-I000065
=
Figure PCTKR2015012953-appb-I000066
Will be reduced to / 2.
도 9는 본 별명의 일실시예에 따른 격자 구조에서 입력 광파의 양방향 입사에 따른 방사되는 출력 광파의 종방향 범위의 확장을 보여주는 개략도이다. 9 is a schematic diagram showing the extension of the longitudinal range of the output light wave emitted by bidirectional incidence of the input light wave in the grating structure according to the embodiment of the present nickname.
도 9를 참조하면, 입력 광파(902-1)의 입사 방향을 왼쪽에서 오른쪽으로 향할 경우에 출력 광파(903-1)의 방사각이 +
Figure PCTKR2015012953-appb-I000067
1이 되도록 격자(901)이 설계되었다면, 또 다른 입력 광파(902-2)를 오른쪽에서 왼쪽으로 향할 경우에 출력 광파(903-2)는 방사각이 -
Figure PCTKR2015012953-appb-I000068
2가 되게 반대쪽으로 보내줄 수 있다. 따라서, 동일한 격자구조에서 입력 광파(902-1, 902-2)의 입사를 양방향으로 해줌으로써 방사 각도는 +
Figure PCTKR2015012953-appb-I000069
1과 -
Figure PCTKR2015012953-appb-I000070
2의 두 가지 각도로 보낼 수 있으므로, 종방향 방사범위를 확대시킬 수 있다. 양방향 입사를 할 수 있는 위상 배열 안테나의 구성은, 간단히, 도 1의 일방향 입사 위상 배열 안테나를 구성하는 소자들을 거울 대칭으로 배치함으로써 구현할 수 있다. 즉, 광원(100), 광 파워 분배기(101-1, 101-2), 위상 제어기(102), 위상 공급선(103)을 발산기(104) 등의 구성 소자들을 우측에도 거울 대칭으로 배치하고, 우측의 위상 공급선들을 발산기의 우측에 연결하는 것이다.Referring to FIG. 9, when the incidence direction of the input light wave 902-1 is from left to right, the emission angle of the output light wave 903-1 is +.
Figure PCTKR2015012953-appb-I000067
If the grating 901 is designed to be 1 , the output light wave 903-2 has a radial angle of − when another input light wave 902-2 is directed from right to left.
Figure PCTKR2015012953-appb-I000068
2 can be sent to the other side. Therefore, the radiation angle is + by making the incidence of the input light waves 902-1 and 902-2 bidirectional in the same lattice structure.
Figure PCTKR2015012953-appb-I000069
1 and-
Figure PCTKR2015012953-appb-I000070
It may be sent to the two angles of the two, it is possible to enlarge the longitudinal radiation range. The configuration of the phased array antenna capable of bidirectional incidence can be realized by simply arranging the elements constituting the one-way incident phased array antenna of FIG. 1 in mirror symmetry. That is, the light source 100, the optical power divider (101-1, 101-2), the phase controller 102, the phase supply line 103 is disposed in the mirror mirror symmetrical components such as the diverter 104, The phase supply lines on the right side are connected to the right side of the diverter.
도 3 내지 도 8을 참조하여 상술한 실시예들에서는 실리콘 광 도파로 코어를 대상으로 하여 자유공간 파장을 1550nm인 예를 들었으나, 이에 제한되거나 한정되지 않고, 광 도파로 코어의 소재는 실리콘에 가까운 굴절률을 갖는 다양한 물질이 이용될 수 있으며, 자유공간 파장 역시 적절한 파장 영역으로 설정됨으로써, 상술한 스케일 법칙이 적용될 수 있다. 예를 들어, 실리콘 소재의 광 도파로에서 파장이
Figure PCTKR2015012953-appb-I000071
인 범위에서 상기 설명된 경향이 적용될 수 있다. 그리고 격자 구조 광 발산기에서 주요 변수인 격자 너비 Wg는 파장 대비
Figure PCTKR2015012953-appb-I000072
범위에서 상기 설명된 경향이 적용될 수 있다.In the embodiments described above with reference to FIGS. 3 to 8, the free-wavelength wavelength is 1550 nm for the silicon optical waveguide core, but the present invention is not limited thereto or limited. The material of the optical waveguide core has a refractive index close to silicon. Various materials may be used, and the free space wavelength may also be set to an appropriate wavelength range, such that the above-described scale law may be applied. For example, in a silicon waveguide, the wavelength
Figure PCTKR2015012953-appb-I000071
The trend described above in the phosphorus range can be applied. And the lattice width Wg, which is the main variable in the lattice structure light emitter
Figure PCTKR2015012953-appb-I000072
In the range the above-described trends can be applied.
이상의 실시예들에서는 격자의 구조가 격자 내에 균일한 구조를 예로 들었으나, 격자의 구조의 변수들(
Figure PCTKR2015012953-appb-I000073
,
Figure PCTKR2015012953-appb-I000074
, Hs, Wg 등) 중에서 하나 이상의 변수를 격자의 길이방향으로 다르게 변화시킬 수도 있다. 또한, 이상의 실시예들에서는 단일 파장을 갖는 광파의 입사를 예로 들었으나, 중심 파장이 하나 이상인 광파 또는 중심파장이 넓은 범위에 걸친 광파를 입사할 수도 있다.In the above embodiments, the structure of the grating is a uniform structure within the grating, but the parameters of the grating structure (
Figure PCTKR2015012953-appb-I000073
,
Figure PCTKR2015012953-appb-I000074
, Hs, Wg, etc.) may be changed differently in the longitudinal direction of the grating. Further, in the above embodiments, the incident of light waves having a single wavelength is taken as an example, but the light waves having one or more center wavelengths or the light waves having a central wavelength may be incident on a wide range.
이상의 실시예들에서 사용된 기호가 나타내는 바는 다음과 같다.The symbols used in the above embodiments are as follows.
X: 격자의 종방향X: longitudinal direction of the grid
Z: 격자의 횡방향Z: Transverse direction of the grid
Y: 격자의 법선방향 (Normal 방향)Y: Normal of the grid (Normal direction)
Dr: 단위 발산기 사이 횡방향 간격Dr: Transverse Spacing Between Unit Dispersers
Figure PCTKR2015012953-appb-I000075
: 자유공간에서 입력 광파의 파장
Figure PCTKR2015012953-appb-I000075
: Wavelength of the input light wave in free space
Figure PCTKR2015012953-appb-I000076
: 격자의 주기
Figure PCTKR2015012953-appb-I000076
: Period of the grid
Figure PCTKR2015012953-appb-I000077
: 단위 격자의 골 부분의 너비
Figure PCTKR2015012953-appb-I000077
: Width of valley of unit grid
Figure PCTKR2015012953-appb-I000078
: 단위 격자의 언덕 부분의 너비
Figure PCTKR2015012953-appb-I000078
Is the width of the hill portion of the unit grid.
Lg: 격자의 길이Lg: length of grid
Ng: 격자주기의 개수Ng: number of grid periods
Hc: 격자 부분 도파로 코어의 두께Hc: thickness of the grating partial waveguide core
Hs: 격자 골의 깊이Hs: Depth of the Lattice
Wg: 광 도파로 코어에서 격자의 너비Wg: width of the grating in the optical waveguide core
M: 어레이 내의 발산기 개수M: Number of diverters in the array
neff: 격자가 형성된 광 도파로의 유효 귤절률 (effective index)n eff : Effective index of grating-formed optical waveguide
nc: 격자가 형성된 광 도파로 위를 덮고 있는 클래드 (clad)의 굴절률n c : Refractive index of the clad covering the grating formed optical waveguide
Figure PCTKR2015012953-appb-I000079
: 단위 격자의 종방향 방사 각도 (법선으로부터 각도)
Figure PCTKR2015012953-appb-I000079
: Longitudinal radiation angle of the unit grid (angle from normal)
Figure PCTKR2015012953-appb-I000080
: 단위 격자의 원거리장의 방사범위를 나타내는 각도 (반구면 좌표계에서 위도)
Figure PCTKR2015012953-appb-I000080
Is the angle representing the radiation range of the far field of the unit grid (latitude in the hemispherical coordinate system).
Figure PCTKR2015012953-appb-I000081
: 위상 배열에서 위상정합 빔이 형성되는 횡방향 각도 (위도)
Figure PCTKR2015012953-appb-I000081
Is the lateral angle (latitude) at which the phase-matching beam is formed in the phased array
Figure PCTKR2015012953-appb-I000082
: 위상 배열에서 위상제어로 얻을 수 있는 위상정합 빔의 횡방향 최대 steering 각도
Figure PCTKR2015012953-appb-I000082
Is the maximum lateral steering angle of the phase-matched beam obtained by phase control in the phased array.
Figure PCTKR2015012953-appb-I000083
: 단위 발산기 사이의 위상차
Figure PCTKR2015012953-appb-I000083
= Phase difference between unit diverters
Figure PCTKR2015012953-appb-I000084
: 위상 배열에서 위상정합 빔의 횡방향 발산각 (divergence angle)
Figure PCTKR2015012953-appb-I000084
= Lateral divergence angle of the phase-matching beam in the phased array
Figure PCTKR2015012953-appb-I000085
: 위상 배열에서 위상정합 빔의 종방향 발산각 (divergence angle)
Figure PCTKR2015012953-appb-I000085
= Longitudinal divergence angle of the phase-matching beam in the phased array
이상과 같이 실시예들이 비록 한정된 실시예와 도면에 의해 설명되었으나, 해당 기술분야에서 통상의 지식을 가진 자라면 상기의 기재로부터 다양한 수정 및 변형이 가능하다. 예를 들어, 설명된 기술들이 설명된 방법과 다른 순서로 수행되거나, 및/또는 설명된 시스템, 구조, 장치, 회로 등의 구성요소들이 설명된 방법과 다른 형태로 결합 또는 조합되거나, 다른 구성요소 또는 균등물에 의하여 대치되거나 치환되더라도 적절한 결과가 달성될 수 있다.Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved.
그러므로, 다른 구현들, 다른 실시예들 및 특허청구범위와 균등한 것들도 후술하는 특허청구범위의 범위에 속한다.Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the claims that follow.

Claims (11)

  1. 광 위상 배열 안테나를 구성하는 광 발산기 소자에 있어서,In the light emitter element constituting the optical phased array antenna,
    반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로; 및 An optical waveguide including a waveguide core and a waveguide clad using a semiconductor material; And
    상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자A grating periodically formed above or below the optical waveguide
    를 포함하고,Including,
    상기 광 발산기 소자는 The light diverter element
    입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사하는, 광 발산기 소자.And an input light wave incident in one direction of the optical waveguide and the grating, and radiating the output light wave into space using scattering from the grating.
  2. 제1항에 있어서,The method of claim 1,
    상기 광 발산기 소자는 The light diverter element
    상기 출력 광파가 방사되는 종방향 각도 범위를 넓히기 위해, 상기 입력 광파를 상기 광 도파로와 상기 격자의 양방향으로 입사하여, 상기 격자로부터의 산란을 이용하여 상기 출력 광파를 공간으로 방사하는, 광 발산기 소자.A light emanator in which the input light wave is incident in both directions of the optical waveguide and the grating to radiate the output light wave into space using scattering from the grating to widen the longitudinal angle range in which the output light wave is radiated device.
  3. 제1항에 있어서,The method of claim 1,
    상기 광 발산기 소자의 기하학적인 변수들-상기 기하학적인 변수들은 상기 도파로 코어의 너비, 상기 도파로 코어의 두께, 상기 격자의 너비, 상기 격자의 주기 및 상기 격자의 깊이를 포함함- 중 적어도 어느 하나의 규모는 At least one of geometric variables of the light emitter element, the geometric variables including the width of the waveguide core, the thickness of the waveguide core, the width of the grating, the period of the grating and the depth of the grating. The scale of
    상기 입력 광파의 파장의 절반인 회절한계 이내의 값 또는 상기 회절한계에 대해 미리 설정된 범위만큼 근접한 값을 갖는, 광 발산기 소자.And a value within a diffraction limit that is half of the wavelength of the input light wave or close to a preset range for the diffraction limit.
  4. 제3항에 있어서,The method of claim 3,
    상기 도파로 코어는 The waveguide core is
    실리콘으로 형성되는, 광 발산기 소자.A light emitter element, formed of silicon.
  5. 제3항에 있어서,The method of claim 3,
    상기 입력 광파의 자유공간 파장
    Figure PCTKR2015012953-appb-I000086
    은     Free space wavelength of the input light wave
    Figure PCTKR2015012953-appb-I000086
    silver
    Figure PCTKR2015012953-appb-I000087
    범위를 갖는, 광 발산기 소자.
    Figure PCTKR2015012953-appb-I000087
    Light emitter device having a range.
  6. 제3항에 있어서,The method of claim 3,
    상기 격자의 너비 Wg는 The width Wg of the grid
    상기 입력 광파의 자유공간 파장
    Figure PCTKR2015012953-appb-I000088
    대비
    Figure PCTKR2015012953-appb-I000089
    범위를 갖는, 광 발산기 소자.    Free space wavelength of the input light wave
    Figure PCTKR2015012953-appb-I000088
    prepare
    Figure PCTKR2015012953-appb-I000089
    Light emitter device having a range.
  7. 제3항에 있어서,The method of claim 3,
    상기 격자의 깊이는 The depth of the grid
    상기 출력 광파가 방사되는 종방향 분포를 제어하기 위하여 조절되는, 광 발산기 소자.And a light diverter device adapted to control the longitudinal distribution in which the output light waves are emitted.
  8. 제3항에 있어서,The method of claim 3,
    상기 격자의 주기는 The period of the grid is
    상기 출력 광파가 방사되는 종방향 방사각을 제어하기 위하여 조절되는, 광 발산기 소자.And a light emitter element adapted to control the longitudinal radiation angle at which said output light wave is emitted.
  9. 제3항에 있어서,The method of claim 3,
    상기 격자의 너비는 The width of the grid
    상기 출력 광파가 방사되는 횡방향 방사 각도 범위를 제어하기 위하여 조절되는, 광 발산기 소자.And a light diverter element adapted to control a range of lateral radiation angles at which said output light waves are emitted.
  10. 반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로 및 상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자를 포함하여, 입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사하는 광 발산기 소자로 구성되는 광 발산기 어레이에 있어서, An optical waveguide including a waveguide core and a waveguide cladding using a semiconductor material, and a grating periodically formed above or below the optical waveguide, and incident light waves are incident in one direction of the optical waveguide and the grating, and scattered from the grating In the light emitter array consisting of a light emitter element for emitting an output light wave to a space by using
    상기 광 발산기 어레이는 The light emitter array
    복수 개의 광 발산기 소자들의 어레이로 생성되고, Generated as an array of a plurality of light emitter elements,
    상기 복수 개의 광 발산기 소자들의 개수는 The number of the plurality of light emitter elements is
    상기 복수 개의 광 발산기 소자들 각각으로부터 방사되는 출력 광파의 위상간섭으로 형성되는 위상정합 빔의 횡방향 빔 발산각을 제어하기 위하여 조절되며,Adjusted to control a lateral beam divergence angle of a phase matching beam formed by phase interference of output light waves emitted from each of the plurality of optical diverter elements,
    상기 복수 개의 광 발산기 소자들 각각에 포함되는 상기 격자의 주기의 개수는 The number of cycles of the grating included in each of the plurality of light emitter elements is
    상기 복수 개의 광 발산기 소자들 각각으로부터 방사되는 출력 광파의 위상간섭으로 형성되는 위상정합 빔의 종방향 빔 발산각을 제어하기 위하여 조절되는, 광 발산기 어레이.And a longitudinal divergence angle of a phase-matching beam formed by phase interference of output light waves emitted from each of the plurality of optical diverter elements.
  11. 반도체 소재를 이용한 도파로 코어와 도파로 클래드를 포함한 광 도파로 및 상기 광 도파로 상부 또는 하부에 주기적으로 형성되는 격자를 포함하여, 입력 광파를 상기 광 도파로와 상기 격자의 일방향으로 입사하고, 상기 격자로부터의 산란을 이용하여 출력 광파를 공간으로 방사하는 광 발산기 소자로 구성되는 광 위상 배열 안테나에 있어서, An optical waveguide including a waveguide core and a waveguide cladding using a semiconductor material, and a grating periodically formed above or below the optical waveguide, and incident light waves are incident in one direction of the optical waveguide and the grating, and scattered from the grating In the optical phased array antenna consisting of a light emitter element for emitting an output light wave into a space by using
    상기 광 위상 배열 안테나는 The optical phased array antenna
    복수 개의 광 발산기 소자들의 어레이로 생성되고, 상기 복수 개의 광 발산기 소자들이 균등한 위상차를 갖도록 커지거나 작아지는 위상을 상기 복수 개의 광 발산기 소자들 각각으로 공급하며, 상기 복수 개의 광 발산기 소자들의 위상 배열에 의한 위상정합 빔을 상기 공간 상에서 횡방향으로 빔 스티어링(steering)하는, 광 위상 배열 안테나.A plurality of light emitter elements, the plurality of light emitter elements being supplied to each of the plurality of light emitter elements, wherein the plurality of light emitter elements are increased or decreased in phase so that the plurality of light emitter elements have an equal phase difference; An optical phased array antenna for beam steering in a transverse direction in said space a phase matched beam by a phased array of elements.
PCT/KR2015/012953 2015-11-17 2015-12-01 Nanophotonic radiator using grid structure for application to photonic phased-array antenna WO2017086524A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080012710A1 (en) * 2006-07-11 2008-01-17 Ramin Sadr Rfid beam forming system
US20110187614A1 (en) * 2008-10-29 2011-08-04 Hideki Kirino High-frequency waveguide and phase shifter using same, radiator, electronic device which uses this phase shifter and radiator, antenna device, and electronic device equipped with same
US20140023318A1 (en) * 2012-07-20 2014-01-23 The Boeing Company Optical antenna and methods for optical beam steering
US20140161464A1 (en) * 2012-07-26 2014-06-12 California Institute Of Technology Optically driven active radiator
US20140192394A1 (en) * 2013-01-08 2014-07-10 Jie Sun Optical phased arrays

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080012710A1 (en) * 2006-07-11 2008-01-17 Ramin Sadr Rfid beam forming system
US20110187614A1 (en) * 2008-10-29 2011-08-04 Hideki Kirino High-frequency waveguide and phase shifter using same, radiator, electronic device which uses this phase shifter and radiator, antenna device, and electronic device equipped with same
US20140023318A1 (en) * 2012-07-20 2014-01-23 The Boeing Company Optical antenna and methods for optical beam steering
US20140161464A1 (en) * 2012-07-26 2014-06-12 California Institute Of Technology Optically driven active radiator
US20140192394A1 (en) * 2013-01-08 2014-07-10 Jie Sun Optical phased arrays

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