WO2019208575A1 - 光半導体装置およびその制御方法 - Google Patents
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- WO2019208575A1 WO2019208575A1 PCT/JP2019/017263 JP2019017263W WO2019208575A1 WO 2019208575 A1 WO2019208575 A1 WO 2019208575A1 JP 2019017263 W JP2019017263 W JP 2019017263W WO 2019208575 A1 WO2019208575 A1 WO 2019208575A1
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- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/022—Mountings; Housings
- H01S5/0239—Combinations of electrical or optical elements
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
- H01S5/0687—Stabilising the frequency of the laser
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- H—ELECTRICITY
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- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
- H01S5/0071—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for beam steering, e.g. using a mirror outside the cavity to change the beam direction
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/14—External cavity lasers
- H01S5/141—External cavity lasers using a wavelength selective device, e.g. a grating or etalon
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/022—Mountings; Housings
- H01S5/02208—Mountings; Housings characterised by the shape of the housings
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/022—Mountings; Housings
- H01S5/023—Mount members, e.g. sub-mount members
- H01S5/02325—Mechanically integrated components on mount members or optical micro-benches
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/024—Arrangements for thermal management
- H01S5/02407—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling
- H01S5/02415—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling by using a thermo-electric cooler [TEC], e.g. Peltier element
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/024—Arrangements for thermal management
- H01S5/02438—Characterized by cooling of elements other than the laser chip, e.g. an optical element being part of an external cavity or a collimating lens
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/026—Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers
- H01S5/0261—Non-optical elements, e.g. laser driver components, heaters
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/0617—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium using memorised or pre-programmed laser characteristics
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
Definitions
- This disclosure relates to an optical semiconductor device and a control method thereof.
- a wavelength tunable laser capable of selecting an output wavelength is disclosed (for example, see Patent Document 1).
- An optical semiconductor device includes a wavelength tunable laser element, a beam splitter that divides the output light of the wavelength tunable laser element into a first light and a second light that are parallel to each other, and the first splitter. And an etalon that transmits the second light, and the optical path length of the etalon with respect to the first light is different from the optical path length with respect to the second light.
- An optical semiconductor device includes a wavelength tunable laser element, a beam splitter that divides the output light of the wavelength tunable laser element into first light and second light, and outputs the first light and An etalon that transmits the second light, and the first light is incident on the etalon from a first direction to form a first optical path in the etalon, and the second light is The etalon is incident from a second direction different from the first direction to form a second optical path in the etalon, and the optical path length of the first optical path is different from the optical path length of the second optical path. is there.
- An optical semiconductor device includes a wavelength tunable laser element, a beam splitter that divides the output light of the wavelength tunable laser element into first light and second light, and outputs the first light and A polarizing plate that changes the polarization state of at least one of the second lights and makes it different from the other polarization state, and transmits the first light and the second light that have passed through the polarizing plate.
- An etalon, and the etalon is made of a material having a specific refractive index corresponding to the polarization of light incident on the etalon.
- An optical semiconductor device control method includes a wavelength tunable laser element, a beam splitter that divides the output light of the wavelength tunable laser element into a first light and a second light that are parallel to each other, and the beam splitter, An etalon that transmits the first light and the second light, a first detector that receives the first light that has passed through the etalon, and a second that receives the second light that has passed through the etalon. And a third detection unit that receives the second light before passing through the etalon, wherein the optical path length of the etalon with respect to the first light is provided.
- the step of driving the wavelength tunable laser element under a driving condition corresponding to the target wavelength of the emitted light of the wavelength tunable laser element, the first detector and the Izu out of the second detector Selecting a target wavelength by using either the one of the detection result and the third detection part of the detection results, it is intended to include.
- FIG. 1A is a plan view illustrating an optical semiconductor device according to the first embodiment.
- FIG. 1B is an enlarged view of the etalon and beam splitter.
- FIG. 2A is a diagram showing the transmission characteristics of an etalon.
- FIG. 2B is a diagram showing the transmission characteristics of etalon.
- FIG. 3 is a plan view illustrating an optical semiconductor device according to Comparative Example 1.
- FIG. 4A is a diagram showing the transmission characteristics of etalon.
- FIG. 4B is a diagram showing the transmission characteristics of etalon.
- FIG. 5 is a plan view illustrating an optical semiconductor device according to Comparative Example 2.
- FIG. 6A is a diagram showing the pass characteristic of an etalon.
- FIG. 6B is a diagram showing the pass characteristic of the etalon.
- FIG. 7A is a diagram showing the pass characteristics of an etalon.
- FIG. 7B is a diagram showing the pass characteristic of the etalon.
- FIG. 8A is a diagram showing the pass characteristic of an etalon.
- FIG. 8B is a diagram showing the pass characteristic of the etalon.
- FIG. 9 is a flowchart illustrating the control executed by the control unit.
- FIG. 10A is a plan view illustrating an optical semiconductor device according to the second embodiment.
- FIG. 10B is an enlarged view of the etalon and beam splitter.
- FIG. 11A is a diagram showing the transmission characteristics of etalon.
- FIG. 11B is a diagram showing the transmission characteristics of etalon.
- FIG. 12 is a plan view illustrating an optical semiconductor device according to the third embodiment.
- FIG. 13A is a diagram showing the transmission characteristics of etalon.
- FIG. 13B is a diagram showing the transmission characteristics of etalon.
- FIG. 14 is a plan view illustrating an optical semiconductor device according to the fourth embodiment.
- FIG. 15A is a plan view illustrating an optical semiconductor device according to the fifth embodiment.
- FIG. 15B is an enlarged view of the etalon and beam splitter.
- ⁇ Etalon is used for wavelength control.
- the etalon has periodic transmission characteristics with respect to the wavelength and frequency of light.
- the transmission characteristics of the etalon are monotonically increasing and monotonically decreasing with respect to the wavelength between the peak showing the maximum value and the bottom showing the minimum value, but are not monotonically increasing and monotonically decreasing near the peak and bottom. Therefore, wavelength control is difficult.
- An object of the present invention is to provide an optical semiconductor device capable of stable wavelength control and a control method therefor.
- One form of the present disclosure includes (1) a wavelength tunable laser element, a beam splitter that divides the output light of the wavelength tunable laser element into a first light and a second light that are parallel to each other, and the first splitter And an etalon that transmits the first light and the second light, and the optical path length of the etalon with respect to the first light is different from the optical path length with respect to the second light.
- the transmission characteristic of one etalon can be adjusted, and manufacturing variations and assembly variations can be suppressed. Therefore, stable wavelength control becomes possible.
- the etalon has a first part that defines an optical path length for the first light, and a second part that defines an optical path length for the second light, and the thickness of the first part.
- the thickness may be different from the thickness of the second portion.
- the first light enters the etalon from a first direction to form a first optical path in the etalon, and the second light passes through the etalon to the first etalon.
- the optical semiconductor device is incident from a second direction different from the direction and forms a second optical path in the etalon, and the optical path length of the first optical path is different from the optical path length of the second optical path.
- the beam splitter includes a first reflecting surface and a second reflecting surface, and the first reflecting surface outputs a part of the emitted light as the first light in the first direction.
- the second reflecting surface may output another part of the emitted light as the second light in the second direction. Thereby, non-parallel first light and second light can be formed, and the incident angles to the etalon can be made different from each other.
- a wavelength tunable laser element a beam splitter that divides the output light of the wavelength tunable laser element into a first light and a second light, and outputs the first light and the second light.
- a polarizing plate that changes the polarization state of at least one of them and makes it different from the polarization state of the other, and an etalon that transmits the first light and the second light that have passed through the polarizing plate.
- the etalon is an optical semiconductor device made of a material having a specific refractive index corresponding to the polarization of light incident on the etalon.
- the polarizing plate includes a first polarizing plate and a second polarizing plate, the first polarizing plate changes a polarization state of the first light, and the second polarizing plate The polarization state may be changed to a polarization state different from that of the first light. Since the polarization states of the first light and the second light can be adjusted, more stable wavelength control is possible.
- the beam splitter may have a reflective surface that reflects the emitted light, and the polarizing plate may be provided on the reflective surface. Thereby, stable wavelength control becomes possible.
- the etalon may have a uniform thickness. By transmitting the first light and the second light having different incident angles to the etalon having a uniform thickness, the transmission characteristics of the etalon can be adjusted.
- the beam splitter has a first reflecting surface that outputs the first light with the emitted light directed toward a first axis, and the second light with the emitted light directed toward a second axis. A second reflecting surface for outputting, wherein the first axis and the second axis are parallel to each other and may be different from the optical axis of the emitted light.
- the reflective surface may transmit a part of the emitted light and output a third light.
- the intensity of the third light that does not pass through the etalon is detected, and wavelength control is performed based on the ratio of the intensity of the third light to the first light and the ratio of the intensity of the third light to the second light. Do.
- a wavelength tunable laser element a beam splitter that divides the emitted light of the wavelength tunable laser element into a first light and a second light that are parallel to each other, and outputs the first light and the second light
- An etalon that transmits light, a first detector that receives the first light that has passed through the etalon, a second detector that receives second light that has passed through the etalon, and the etalon that passes through
- An optical semiconductor device comprising: a third detection unit that receives the second light before the first light, wherein an optical path length of the etalon with respect to the first light is an optical path length with respect to the second light Unlike the step, the step of driving the wavelength tunable laser element under a driving condition corresponding to the target wavelength of the emitted light of the wavelength tunable laser element, and any one of the first detection unit and the second detection unit One detection result and the third detection Selecting a target wavelength with a detection result of the part, a control method for an optical semiconductor
- An optical semiconductor device control method further comprising a memory for storing drive information of the wavelength tunable laser element, wherein the step of selecting the target wavelength is stored in the memory based on the target wavelength
- a step of selecting which of the first detection unit and the second detection unit to use may be included.
- FIG. 1A is a plan view illustrating an optical semiconductor device 100 according to the first embodiment.
- a one-dot chain line indicates light.
- the X direction and the Y direction are orthogonal to each other.
- an optical semiconductor device 100 includes a package 10, a TEC (Thermoelectric Cooler) 12, a carrier 14, a wavelength tunable laser element 16, a lens folder 18, beam splitters 20 and 22, an etalon 24, light receiving elements 26 and 28. And 30.
- TEC Thermoelectric Cooler
- the upper surface of the package 10 extends in the XY plane, and the TEC 12 is mounted on the upper surface.
- a carrier 14 On the TEC 12, a carrier 14, a lens folder 18, beam splitters 20 and 22, an etalon 24, and light receiving elements 26, 28, and 30 are mounted.
- a wavelength tunable laser element 16 is mounted on the carrier 14.
- the lens folder 18 is located on the ⁇ X side of the output end of the wavelength tunable laser element 16, and the beam splitter 20 is located on the ⁇ X side of the lens folder 18.
- the beam splitter 22 is located on the + Y side of the beam splitter 20, and the light receiving element 30 is located on the + Y side of the beam splitter 22.
- the etalon 24 is located on the + X side of the beam splitter 22.
- the light receiving elements 26 and 28 are located on the + X side of the etalon 24 and are arranged along the Y direction.
- the TEC 12 includes a Peltier element and functions as a temperature control device that controls the temperatures of the wavelength tunable laser element 16 and the etalon 24.
- the wavelength tunable laser element 16 includes a tunable semiconductor laser capable of controlling the wavelength, and outputs a laser beam L0.
- the tunable laser element 16 includes, for example, a partial diffraction grating active region (SG-DFB: Sampled Grating Distributed Feedback), a CSG-DBR (Chirped Sampled Grating Distributed Bragg Reflector) region, and an SOA (Semiconductor Optical Amplifier) region. By injecting carriers into the SG-DFB region, the wavelength tunable laser element 16 oscillates.
- SG-DFB Sampled Grating Distributed Feedback
- CSG-DBR Cold Sampled Grating Distributed Bragg Reflector
- SOA semiconductor Optical Amplifier
- a heater is provided in the CSG-DBR region, and when power is input to the heater, the temperature of the CSG-DBR region changes and the refractive index changes. As a result, the wavelength of the laser beam L0 changes. By inputting a current into the SOA region, the intensity of the laser beam L0 is adjusted.
- the lens folder 18 holds a lens.
- the beam splitters 20 and 22 are, for example, cube-type beam splitters.
- the beam splitter 20 transmits a part of the laser light L0 output from the wavelength tunable laser element 16 to the ⁇ X side and reflects a part to the + Y side.
- the laser light L0 that has passed through the beam splitter 20 is output light that is output from the optical semiconductor device 100 to the outside.
- the beam splitter 22 has two reflecting surfaces 22a and 22b parallel to each other.
- One of the laser beams L0 branched at the beam splitter 20 is incident on the reflection surface 22b (second reflection surface), and further branched at the reflection surface 22b.
- Light L ⁇ b> 2 (second light) that is one of the light branched off at the reflecting surface 22 b propagates in the + X direction, passes through the etalon 24, and enters the light receiving element 28.
- the light transmitted through the reflecting surface 22b enters the reflecting surface 22a (first reflecting surface) and branches.
- Light L ⁇ b> 1 (first light) that is one of the light branched off at the reflecting surface 22 a propagates in the + X direction, passes through the etalon 24, and enters the light receiving element 26.
- the optical axes of the lights L1 and L2 are parallel to each other and are different from the optical axis of the laser light L0.
- the light transmitted through the reflecting surfaces 22 b and 22 a is input to the light receiving element 30.
- the etalon 24 is made of, for example, crystal.
- the transmittance of the etalon 24 changes periodically according to the wavelength of incident light.
- the light receiving elements 26, 28 and 30 are, for example, photodiodes, and output current by receiving light.
- FIG. 1B is an enlarged view of the etalon 24 and the beam splitter 22.
- the etalon 24 is inclined with respect to the X axis and the Y axis, and the angle between the etalon 24 and the Y axis is ⁇ 1.
- the surface 24 c of the etalon 24 is a flat surface facing the light receiving elements 26 and 28.
- the surfaces 24 a and 24 b are surfaces opposite to the surface 24 c and face the beam splitter 22.
- the surface 24a is located on the + X side of the reflecting surface 22a of the beam splitter 22, and the light L1 enters.
- the surface 24b is located on the + X side of the reflecting surface 22b, and the light L2 enters.
- the light L1 and the light L2 formed by the reflective surfaces 22a and 22b parallel to each other are parallel to each other. Therefore, the incident angle of the light L1 to the etalon 24 is equal to the incident angle of the light L2 and is ⁇ 1.
- a step 24d is formed between the surface 24a and the surface 24b.
- the thickness of the etalon 24 changes with the step 24d as a boundary, and the thickness T2 between the surface 24b and the surface 24c is larger than the thickness T1 between the surface 24a and the surface 24c.
- the optical path length of the light L1 in the etalon 24 becomes smaller than the optical path length of the light L2 in the etalon 24. Therefore, the optical path length of the part of the etalon 24 where the light L1 is determined is smaller than the optical path length of the part of the etalon 24 where the light L2 is determined.
- the light receiving element 30 receives light that does not pass through the etalon 24 and outputs a photocurrent Im3.
- the light receiving element 26 receives the light L1 transmitted between the surfaces 24a and 24c of the etalon 24 and outputs a photocurrent Im1.
- the light receiving element 28 receives the light L2 that passes between the surfaces 24b and 24c of the etalon 24, and outputs a photocurrent Im1.
- the photocurrent changes according to the intensity of each light.
- the ratio of the photocurrents Im1 and Im3 corresponds to the ratio of the intensity of the light L1 and L3, and the ratio of Im2 and Im3 corresponds to the ratio of the intensity of the lights L2 and L3, and wavelength control is performed based on these ratios.
- the control unit 35 is an electronic device electrically connected to the TEC 12, the wavelength tunable laser element 16, and the light receiving element, outputs electrical signals of the TEC 12 and the wavelength tunable laser element 16, and detects a photocurrent output from the light receiving element. To do. When the control unit 35 inputs electric power to a heater (not shown) of the wavelength tunable laser element 16, the temperature of the wavelength tunable laser element 16 changes and the oscillation wavelength changes. Further, when the control unit 35 inputs a current into the SOA region of the wavelength tunable laser element 16, the intensity of the emitted light from the wavelength tunable laser element 16 changes.
- the control unit 35 includes a memory, and a transmittance according to the wavelength is stored in the memory.
- FIGS. 2A and 2B are diagrams showing the transmission characteristics of the etalon 24.
- FIG. The transmission characteristics of the etalon 24 are determined by the optical path length of light within the etalon 24 (the resonator length of the etalon 24), the refractive index of the etalon 24, and the incident angle of light.
- desired transmission characteristics as shown in FIGS. 2A and 2B are realized, and stable wavelength control is enabled.
- FIG. 3 is a plan view illustrating an optical semiconductor device 100R according to the first comparative example.
- the beam splitter 21 is located on the + Y side of the beam splitter 20 and has one reflecting surface.
- the light receiving element 30 is located on the + Y side of the beam splitter 20 and receives light transmitted through the beam splitter 20.
- the etalon 24 and the light receiving element 26 are located on the + X side of the beam splitter 21, and the light L1 enters.
- FIGS. 4A and 4B are diagrams showing the transmission characteristics of the etalon 24.
- FIG. The horizontal axis represents the frequency of light. In FIG. 4A, the range is 191.250 THz to 191.450 THz, and in FIG. 4B, the range is 196.100 THz to 196.300 THz.
- the vertical axis represents the photocurrent ratio Im1 / Im3 and represents the transmission characteristics of the etalon 24.
- the ratio Im1 / Im3 that is, the transmission characteristics, periodically changes with respect to frequency and wavelength. That is, the peak P at which the ratio takes a maximum value and the bottom B at which the ratio takes a minimum value are alternately arranged.
- the ratio monotonously increases or monotonously decreases as the frequency increases, so that wavelength control based on the ratio is easy.
- the ratio does not monotonously increase or decrease monotonously. That is, in the vicinity of the peak P, there are a portion where the ratio increases and a portion where the ratio increases as the frequency increases, with the maximum value interposed therebetween. Even in the vicinity of the bottom B, there are an increasing portion and a decreasing portion with a minimum value therebetween. For this reason, wavelength control is difficult.
- FIG. 5 is a plan view illustrating an optical semiconductor device 200R according to the second comparative example.
- the beam splitter 23 is disposed on the + X side of the beam splitter 21, the etalon 24 is disposed on the + X side of the beam splitter 23, and the etalon 25 is disposed on the + Y side.
- the beam splitter 23 branches the light output from the beam splitter 21 into light L1 and L2.
- the light receiving element 26 receives the light L1 transmitted through the etalon 24, and the light receiving element 28 receives the light L2 transmitted through the etalon 25.
- FIG. 6A to 8B are diagrams showing the pass characteristics of the etalons 24 and 25.
- FIG. The solid line represents the ratio Im1 / Im3 and corresponds to the pass characteristic of the etalon 24.
- the broken line represents the ratio Im2 / Im3 and corresponds to the pass characteristic of the etalon 25.
- the ratio Im1 / Im3 and the ratio Im2 / Im3 have the same period and are shifted from each other by about 1 ⁇ 4 period. For this reason, at the frequency at which the ratio Im1 / Im3 becomes the peak P1 or the bottom B1, the ratio Im2 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im2 / Im3. Further, at the frequency at which the ratio Im2 / Im3 becomes the peak P2 or the bottom B2, the ratio Im1 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im1 / Im3.
- the transmission characteristics of the two etalons 24 and 25 are shown in FIG. 6A and FIG. It is difficult to adjust like this. For example, the intended transmission characteristics may not be obtained due to variations in etalon thickness and incident angle.
- the peak P1 and the peak P2 are located at the same frequency, and the bottom B1 and the bottom B2 are located at the same frequency.
- the peak P1 and the bottom B2 are located at the same frequency, and the bottom B1 and the peak P2 are located at the same frequency. Therefore, it is difficult to control the wavelength regardless of which of the etalons 24 and 25 is used.
- Example 1 uses one etalon 24 and beam splitters 20 and 22, and the configuration is simpler than that of Comparative Example 2. For this reason, manufacturing variation and assembly variation can be suppressed.
- the optical path lengths and incident angles of the lights L1 and L2 can be determined more accurately.
- the transmission characteristics of the etalon 24 are determined by the optical path length, the incident angle, and the refractive index.
- the transmission characteristics of the etalon 24 with respect to the light L1 are different from the transmission characteristics with respect to the light L2 by making the optical path lengths of the lights L1 and L2 different. Therefore, stable wavelength control is possible.
- Table 1 is a table illustrating the incident angles of the light L1 and L2 to the etalon 24, the thickness of the etalon 24, the refractive index of the etalon 24, and the reflectance of the etalon 24. As shown in Table 1, the incident angle, the refractive index, and the reflectance are the same for the lights L1 and L2. On the other hand, the thickness (optical path length) of the portion of the etalon 24 through which the light L2 is transmitted is 0.97 mm + 0.14 ⁇ m, which is 0.14 ⁇ m larger than the thickness of the portion through which the light L1 is transmitted, 0.97 mm.
- the transmission characteristic of the etalon 24 with respect to the light L1 (corresponding to Im1 / Im3) and the transmission characteristic of the etalon 24 with respect to the light L2 (corresponding to Im2 / Im3) can be adjusted as shown in FIGS. 2A and 2B. .
- the ratio Im1 / Im3 and the ratio Im2 / Im3 have the same period and are shifted from each other by about 1 ⁇ 4 period. For this reason, at the frequency at which the ratio Im1 / Im3 becomes the peak P1 or the bottom B1, the ratio Im2 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im2 / Im3. Further, at the frequency at which the ratio Im2 / Im3 becomes the peak P2 or the bottom B2, the ratio Im1 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im1 / Im3.
- FIG. 9 is a flowchart illustrating the control executed by the control unit 35.
- the control unit 35 acquires a wavelength request (step S20).
- the control unit 35 extracts a control condition corresponding to the target wavelength from the memory (step S22).
- the control unit 35 drives the wavelength tunable laser element 16 (step S24) and drives the TEC 12 (step S26).
- the current and power at this time are values corresponding to the required wavelength among the initial setting values shown in FIG.
- the control unit 35 determines whether or not the temperature acquired from a temperature sensor (not shown) is within the set range (step S28).
- the setting range is a predetermined range centered on the target temperature of the wavelength tunable laser element 16 and the etalon. When it determines with No, the control part 35 changes the electric current value supplied to TEC12 so that temperature TH may become in a setting range.
- the control unit 35 executes AFC and APC in parallel. First, AFC will be described.
- the control unit 35 obtains the current Im1 and current Im2 output from the light receiving elements 26 and 28 and the current Im3 output from the light receiving element 30, and calculates a ratio thereof (step S30). Wavelength control is performed using one of the ratios Im1 / Im3 and Im2 / Im3 (transmittance).
- the memory of the control unit 35 stores a value of the ratio with respect to the wavelength, and refers to the value to select a side that indicates monotonic increase or monotonic decrease from the ratio and uses it for AFC.
- Control unit 35 determines whether the ratio is within the target range (step S32).
- the target range is a predetermined range from the values of the ratios Im1 / Im3 and Im2 / Im3 corresponding to the frequency, for example, as shown in FIGS. 2A and 2B.
- the control part 35 controls the electric power P input into the heater of the wavelength tunable laser element 16, for example (step S34). As a result, the temperature of the wavelength tunable laser element 16 is changed to adjust the oscillation wavelength to the target wavelength. Wavelength control is possible by setting the ratio within a desired range. If the ratio is within the target range, the desired wavelength is obtained. In this case, it is determined as Yes, and the control unit 35 continues the AFC so as to maintain the state.
- the control unit 35 acquires the current Im3 output from the light receiving element 30 (step S36), and determines whether or not the current Im3 is within the set range (step S38).
- the setting range is a predetermined range centered on the target value of current.
- the control part 35 controls the electric current I input into the SOA area
- the control part 35 continues APC so that the state may be maintained. If it is determined Yes in steps S38 and S48, the control is terminated.
- the optical path length is made different between the light L1 and the light L2. Since the manufacturing variation is smaller than that of the two etalons, stable wavelength control is possible.
- the beam splitter 22 has reflection surfaces 22a and 22b parallel to each other, and emits light L1 and L2 parallel to each other.
- the incident angles to the etalon 24 are equal, and the refractive indexes of the etalon 24 with respect to the lights L1 and L2 are also the same. Therefore, transmission characteristics can be controlled mainly by adjusting the thickness (optical path length), and stable wavelength control is possible.
- FIG. 10A is a plan view illustrating the optical semiconductor device 200 according to the second embodiment
- FIG. 10B is an enlarged view of the etalon 24 and the beam splitter 22. The description of the same configuration as that of the first embodiment is omitted.
- the surface 24e of the etalon 24 facing the beam splitter 22 is flat, and no step is formed. That is, the thickness of the etalon 24 is uniform.
- the surface 24f of the etalon 24 is the surface opposite to the surface 24e and faces the light receiving elements 26 and 28.
- the beam splitter 22 has two reflecting surfaces 22a and 22b.
- the reflecting surface 22a and the reflecting surface 22b are non-parallel, and the angle between them is ⁇ 2.
- Each of the reflection surfaces 22a and 22b branches incident light.
- Light L1 is output in the + X direction from the reflecting surface 22a.
- Light L2 is output from the reflecting surface 22b in a direction shifted by an angle ⁇ 2 from the + X direction.
- the light L1 and the light L2 are non-parallel, and the incident angles to the etalon 24 are also different from each other.
- the thickness of the etalon 24 is uniform, since the incident angle is different, the optical path length of the light L1 is different from the optical path length of the light L2. For this reason, the transmission characteristic of the etalon 24 for the light L1 is different from the transmission characteristic for the light L2.
- manufacturing variations and assembly variations can be suppressed, and stable wavelength control is possible.
- Table 2 is a table illustrating the incident angles of the light L1 and L2 to the etalon 24, the thickness of the etalon 24, the refractive index of the etalon 24, and the reflectance of the etalon 24. As shown in Table 2, the thickness, refractive index, and reflectance for the lights L1 and L2 are the same. On the other hand, the incident angle of the light L2 is 1.73 + 0.43 °, which is 0.43 ° larger than the incident angle of the light L1 of 1.73 °.
- the transmission characteristic of the etalon 24 with respect to the light L1 (corresponding to Im1 / Im3) and the transmission characteristic of the etalon 24 with respect to the light L2 (corresponding to Im2 / Im3) can be adjusted as shown in FIGS. 11A and 11B. .
- FIG. 11A and 11B are diagrams showing the transmission characteristics of the etalon 24.
- FIG. The ratio Im1 / Im3 and the ratio Im2 / Im3 have the same period and are shifted from each other by about 1 ⁇ 4 period. For this reason, according to the second embodiment, stable wavelength control is possible as in the first embodiment.
- the beam splitter 22 includes two non-parallel reflecting surfaces 22a and 22b, so that the incident angles of the lights L1 and L2 to one etalon 24 are made different.
- the thickness between the surface 24e and the surface 24f is the same, the incident angles of the light L1 and L2 in the site
- the optical path length of the light L1 in the etalon 24 becomes smaller than the optical path length of the light L2 in the etalon 24. Therefore, the optical path length of the part of the etalon 24 where the light L1 is determined is smaller than the optical path length of the part of the etalon 24 where the light L2 is determined.
- manufacturing variation and assembly variation are suppressed, stable wavelength control is possible.
- the etalon 24 has a uniform thickness, and the refractive index of the etalon 24 with respect to the lights L1 and L2 is also the same. Therefore, transmission characteristics can be controlled mainly by adjusting the angle ⁇ 2 between the reflecting surfaces 22a and 22b. Thereby, stable wavelength control is possible.
- FIG. 12 is a plan view illustrating an optical semiconductor device 300 according to the third embodiment. The description of the same configuration as in the first or second embodiment is omitted.
- the etalon 24 has a uniform thickness
- the beam splitter 22 has two reflecting surfaces 22a and 22b parallel to each other. The light L1 emitted from the reflecting surface 22a and the light L2 emitted from the reflecting surface 22b are parallel to each other.
- Polarizing plates 32 and 34 are provided on the surface of the beam splitter 22 facing the etalon 24. In the X-axis direction, the polarizing plate 32 is located between the reflecting surface 22 a and the etalon 24, and the polarizing plate 34 is located between the reflecting surface 22 b and the etalon 24.
- the light L1 is incident on the etalon 24 after the polarization state is changed by passing through the polarizing plate 32 (first polarizing plate).
- the light L2 passes through the polarizing plate 34 (second polarizing plate) and changes its polarization state, and then enters the etalon 24.
- the polarization state of the light L1 after passing through the polarizing plate is different from the polarization state of the light L2.
- the etalon 24 is formed of an anisotropic crystal such as quartz, for example, and has a specific refractive index according to the polarization state of incident light. Since the lights L1 and L2 are in different polarization states, the refractive index of the etalon 24 with respect to the light L1 is different from the refractive index with respect to the light L2. Therefore, the transmission characteristic of the etalon 24 for the light L1 is different from the transmission characteristic for the light L2. According to the third embodiment, manufacturing variations and assembly variations can be suppressed, and stable wavelength control is possible.
- Table 3 is a table illustrating the incident angles of the light L1 and L2 to the etalon 24, the thickness of the etalon 24, the refractive index of the etalon 24, and the reflectance of the etalon 24. As shown in Table 3, the incident angle, thickness (optical path length), and reflectivity for the lights L1 and L2 are the same. On the other hand, the refractive index for the light L2 is 1.544937, which is larger than the refractive index for the light L1 of 1.5443.
- the transmission characteristic of the etalon 24 with respect to the light L1 (corresponding to Im1 / Im3) and the transmission characteristic of the etalon 24 with respect to the light L2 (corresponding to Im2 / Im3) can be adjusted as shown in FIGS. 13A and 13B.
- FIG. 13A and 13B are diagrams showing the transmission characteristics of the etalon 24.
- FIG. The ratio Im1 / Im3 and the ratio Im2 / Im3 have the same period and are shifted from each other by about 1 ⁇ 4 period. For this reason, according to the third embodiment, stable wavelength control is possible as in the first and second embodiments.
- Example 3 since one etalon 24 and polarizing plates 32 and 34 that cause birefringence may be used, manufacturing variation and assembly variation are suppressed. Therefore, stable wavelength control is possible.
- the etalon 24 has a uniform thickness, and the beam splitter 22 has reflecting surfaces 22a and 22b parallel to each other.
- the transmission characteristics can be controlled by adjusting the polarization state after passing through the polarizing plates 32 and 34 and the refractive index of the etalon 24, and stable wavelength control is possible.
- the number of polarizing plates may be one, and it is only necessary to change the polarization state of at least one of the lights L1 and L2. This is because the same effect can be obtained by making the polarization states of the lights L1 and L2 different.
- FIG. 14 is a plan view illustrating an optical semiconductor device 400 according to the fourth embodiment. The description of the same configuration as that of the third embodiment is omitted.
- the beam splitter 22 has two reflecting surfaces 22a and 22b parallel to each other, and a polarizing reflecting plate 36 is provided on the reflecting surface 22a.
- the polarization reflector 36 is, for example, a reflective polarizing film, and changes and reflects the polarization state of light.
- the two reflecting surfaces 22a and 22b reflect some light and transmit some light.
- the polarization reflector 36 reflects the light L1 whose polarization state changes, and transmits the light L3 whose polarization state changes.
- the polarization state of the light L1 is different from the polarization state of the light L2.
- the refractive index of the etalon 24 for the light L1 is different from the refractive index for the light L2. Therefore, according to the fourth embodiment, the transmission characteristics of the etalon 24 for the light L1 are different from the transmission characteristics for the light L2, and stable wavelength control is possible.
- FIG. 15A is a plan view illustrating an optical semiconductor device 500 according to the fifth embodiment
- FIG. 15B is an enlarged view of the vicinity of the variable polarizing plate 40 and the beam splitter 42.
- a one-dot chain line indicates light.
- the optical semiconductor device 500 includes a package 10, a TEC 12, a carrier 14, a wavelength tunable laser element 16, a lens folder 18, a beam splitter 20, a variable polarizing plate 40, a beam splitter 42, an etalon 44, and a light receiving element 28.
- the control unit 35 is connected to the wavelength variable laser element 16, the light receiving elements 28 and 30, and the variable polarizing plate 40.
- the lens folder 18 is located on the ⁇ X side of the output end of the wavelength tunable laser element 16, and the beam splitter 20 is located on the ⁇ X side of the lens folder 18.
- the variable polarizing plate 40 is located on the + Y side of the beam splitter 20, and the beam splitter 42 is located on the + Y side of the variable polarizing plate 40.
- the light receiving element 30 (third detection unit) is located on the ⁇ X side of the beam splitter 42.
- the etalon 44 is located on the + X and + Y sides of the beam splitter 42.
- the light receiving element 28 is located on the opposite side of the etalon 44 from the beam splitter 42 side.
- the variable polarizing plate 40 is made of, for example, liquid crystal or dielectric anisotropic crystal such as lithium niobate (LiNbO 3 ).
- the variable polarizing plate 40 changes the polarization state of the incident light L ⁇ b> 0 according to the control signal input from the control unit 35.
- the beam splitter 42 is an optically anisotropic crystal formed of, for example, calcite or quartz and having different optical properties depending on the direction of the crystal axis, and is a prism that birefringes light.
- the beam splitter 42 has a specific refractive index according to the polarization state of incident light.
- the beam splitter 42 refracts the light L0 whose polarization state has been changed by the variable polarizing plate 40, and emits light L1, L2, and L3.
- variable polarizing plate 40 When no control signal is input to the variable polarizing plate 40, the variable polarizing plate 40 sets the polarization state of the light L0 to a certain state (first state). The beam splitter 42 refracts the light L0 and emits light L1 (first light). When a control signal is input to the variable polarizing plate 40, the variable polarizing plate 40 changes the polarization state of the light L0 to another state (second state). The beam splitter 42 refracts the light L0 and emits light L2 (second light). Since the beam splitter 42 has different refractive indexes with respect to lights having different polarization states, the emission direction of the light L1 and the emission direction of the light L2 are different from each other. Therefore, as shown in FIG.
- the emission directions of the light L1 and the light L2 are different from each other by an angle ⁇ .
- the optical path (first optical path) in the etalon 44 of the light L1 and the optical path (second optical path) in the etalon 44 of the light L2 have different optical path lengths. Note that the angles of the incident directions when the lights L1 and L2 are incident on the beam splitter 42 are different from each other.
- the etalon 44 is inclined with respect to the X axis and the Y axis and has a uniform thickness T.
- One surface faces the beam splitter 42 and the other surface faces the light receiving element 28.
- Lights L1 and L2 enter the etalon 44, and the etalon 44 passes the lights L1 and L2.
- the etalon 44 is made of, for example, quartz or the like, and the transmittance periodically changes according to the wavelength of incident light.
- the light receiving element 28 receives the light L1 and L2 that have passed through the etalon 44, outputs a current Im1 in response to the incidence of the light L1, and a current Im2 in response to the incidence of the light L2. Is output.
- the light receiving element 30 receives the light L3 that does not pass through the etalon 44 and is emitted in the ⁇ X direction, and outputs a photocurrent Im3.
- the photocurrent changes according to the light intensity.
- the ratio of the photocurrents Im1 and Im3 corresponds to the ratio of the intensity of the light L1 and L3, and the ratio of Im2 and Im3 corresponds to the ratio of the intensity of the lights L2 and L3, and wavelength control is performed based on these ratios.
- Example 5 the optical path lengths are also made different by making the incident angles to the etalon 44 different between the light L1 and the light L2.
- desired transmission characteristics as shown in FIGS. 2A and 2B are realized, and stable wavelength control is enabled.
- variable polarizing plate 40 changes the polarization state of the light L0, and the beam splitter 42 emits the light L1 and L2 in different directions according to the polarization state. Therefore, the incident angles and the optical path lengths of the lights L1 and L2 are different from each other, and the transmission characteristics of the etalon 44 with respect to the light L1 are different from the transmission characteristics with respect to the light L2. Therefore, stable wavelength control is possible.
- Table 4 is a table illustrating the incident angles of the light L1 and L2 to the etalon 44, the thickness of the etalon 44, the refractive index of the etalon 44, and the reflectance of the etalon 44. As shown in Table 4, the thickness, the refractive index, and the reflectance are the same for the lights L1 and L2. On the other hand, the incident angle of the light L1 is, for example, 0 °, and the incident angle of the light L2 is, for example, 0.28 °. As a result, the optical path lengths are also different from each other.
- the transmission characteristics of the etalon 44 with respect to the light L1 (corresponding to Im1 / Im3) and the transmission characteristics of the etalon 44 with respect to the light L2 (corresponding to Im2 / Im3) are different from each other as shown in FIGS. 2A and 2B. be able to.
- the ratio Im1 / Im3 and the ratio Im2 / Im3 have the same period, for example, 3/16 period to 5/16 period In the range, they are shifted from each other by about 1 ⁇ 4 period. For this reason, at the frequency at which the ratio Im1 / Im3 becomes the peak P1 or the bottom B1, the ratio Im2 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im2 / Im3. Further, at the frequency at which the ratio Im2 / Im3 becomes the peak P2 or the bottom B2, the ratio Im1 / Im3 shows a monotone increase or a monotone decrease. At this time, wavelength control may be performed using the ratio Im1 / Im3. As a result, stable wavelength control is possible.
- the control unit 35 inputs an electric signal to the wavelength tunable laser element 16 to drive the wavelength tunable laser element 16, and inputs an electric signal to the variable polarizing plate 40 to change the polarization state of the light L 0. And 30 output currents are detected to control the wavelength. Specifically, the control unit 35 acquires the transmittance according to the target wavelength from the memory, and inputs an electric signal to the variable polarizing plate 40 so as to obtain the transmittance. Therefore, a desired polarization state is obtained by the variable polarizing plate 40, and stable wavelength control is possible.
- Example 5 uses one etalon 44, a variable polarizing plate 40, and a beam splitter 42 as shown in FIGS. 15A and 15B, and has a simpler configuration than that of Comparative Example 2. For this reason, manufacturing variation and assembly variation can be suppressed. Therefore, the incident angles and optical path lengths of the lights L1 and L2 can be determined more accurately.
- variable polarizing plate 40 Since the variable polarizing plate 40 is made of liquid crystal or dielectric, the rotation angle of the polarization direction is variable.
- the variable polarizing plate 40 can change the polarization state of the emitted light into two or more states according to a control signal input from the control unit 35.
- the beam splitter 42 refracts and emits light in different directions according to the polarization state. Thereby, the transmission characteristics of the etalon 44 as shown in FIGS. 2A and 2B can be obtained. Since one variable polarization plate 40 emits light having different polarization states, manufacturing variation and assembly variation are suppressed, and stable wavelength control is possible.
- the beam splitter 42 emits light L1, L2, and L3. Therefore, the wavelength can be controlled by the intensity ratio (Im1 / Im3) between the lights L1 and L3 and the intensity ratio between the lights L2 and L3 (Im2 / Im3).
- the beam splitter 42 only needs to change the emitting direction according to the polarization state of light.
- the beam splitter 42 is a prism made of an anisotropic crystal and birefringent light.
- the beam splitter 42 is made of calcite or quartz and exhibits good birefringence.
- One beam splitter 42 birefringes light having different deflection states emitted from the variable polarizing plate 40 and emits light L1 and L2. For this reason, manufacturing variation and assembly variation are suppressed, and stable wavelength control is possible.
- the etalon 44 has a uniform thickness, and the refractive index of the etalon 44 with respect to the lights L1 and L2 is also the same. For this reason, transmission characteristics can be controlled by the emission directions of the light L1 and L2 from the beam splitter 42. Thereby, stable wavelength control is possible.
- the variable polarizing plate 40 and the beam splitter 42 are located on the ⁇ X side (laser beam emission direction side) of the wavelength tunable laser element 16.
- the etalon 44 is positioned closer to the wavelength tunable laser element 16 than the variable polarizing plate 40 and the beam splitter 42 along the X axis.
- the laser light is emitted from the wavelength tunable laser element 16 in the ⁇ X direction, and propagates from the beam splitter 20 to the etalon 44 in the + X direction. For this reason, the package 10 does not have to be elongated in the X direction, for example, and the optical semiconductor device 500 can be downsized.
- Optical semiconductor device 10 package 12 TEC 14 Carrier 16 Wavelength tunable laser element 18 Lens folder 20, 21, 22, 23, 42 Beam splitter 22a, 22b Reflecting surface 24, 25, 44 Etalon 26, 28, 30 Light receiving element 32, 34 Polarizing plate 36 Polarizing reflector 40 Variable Polarizing plate 100, 200, 300, 400, 500 Optical semiconductor device
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Abstract
Description
最初に本開示の実施形態の内容を列記して説明する。
本開示の一形態は、(1)波長可変レーザ素子と、前記波長可変レーザ素子の出射光を、互いに平行な第1の光と第2の光とに分岐し出力するビームスプリッタと、前記第1の光および前記第2の光を透過するエタロンと、を具備し、前記エタロンの前記第1の光に対する光路長は前記第2の光に対する光路長とは異なる光半導体装置である。これにより1つのエタロンの透過特性を調整することができ、製造バラツキおよび組み立てバラツキなどを抑制することができる。しがたって安定した波長制御が可能となる。
(2)前記エタロンは前記第1の光に対する光路長を画定する第1の部位と、前記第2の光に対する光路長を画定する第2の部位とを有し、前記第1の部位の厚さは前記第2の部位の厚さとは異なってもよい。エタロンの厚さが変わることで、第1の光の光路長は第2の光の光路長より大きくなる。このため安定した波長制御が可能である。
(3)波長可変レーザ素子と、前記波長可変レーザ素子の出射光を、第1の光と第2の光とに分岐し出力するビームスプリッタと、前記第1の光および前記第2の光を透過するエタロンと、を具備し、前記第1の光は前記エタロンへ第1の方向から入射し前記エタロン内で第1の光路を形成し、前記第2の光は前記エタロンに前記第1の方向とは異なる第2の方向から入射し前記エタロン内で第2の光路を形成し、前記第1の光路の光路長は前記第2の光路の光路長と異なる光半導体装置である。これにより1つのエタロンの透過特性を調整することができ、製造バラツキおよび組み立てバラツキなどを抑制することができる。しがたって安定した波長制御が可能となる。
(4)前記ビームスプリッタは第1の反射面と第2の反射面とを備え、前記第1の反射面は前記出射光の一部を前記第1の光として前記第1の方向に出力し、前記第2の反射面は前記出射光の他の一部を前記第2の光として前記第2方向に出力してもよい。これにより非平行な第1の光および第2の光を形成し、エタロンへの入射角を互いに異ならせることができる。
(5)波長可変レーザ素子と、前記波長可変レーザ素子の出射光を、第1の光と第2の光とに分岐し出力するビームスプリッタと、前記第1の光および前記第2の光のうち少なくとも一方の偏波状態を変化させ、他方の偏波状態とは異ならせる偏光板と、前記偏光板を通過した前記第1の光および前記第2の光を透過するエタロンと、を具備し、前記エタロンは、前記エタロンに入射する光の偏波に対応して固有の屈折率を有する材料で構成されている光半導体装置である。これにより1つのエタロンの透過特性を調整することができ、製造バラツキおよび組み立てバラツキなどを抑制することができる。しがたって安定した波長制御が可能となる。
(6)前記偏光板は第1偏光板および第2偏光板を含み、前記第1偏光板は前記第1の光の偏波状態を変化させ、前記第2偏光板は前記第2の光の偏波状態を前記第1の光とは異なる偏波状態に変化させてもよい。第1の光および第2の光の偏波状態を調整することができるため、より安定した波長制御が可能である。
(7)前記ビームスプリッタは前記出射光を反射する反射面を有し、前記偏光板は前記反射面に設けられてもよい。これにより安定した波長制御が可能となる。
(8)前記エタロンは一様の厚さを有してもよい。一様な厚さのエタロンに、入射角の異なる第1の光および第2の光が入射することで、エタロンの透過特性を調整することができる。
(9)前記ビームスプリッタは、前記出射光を第1の軸に向けて前記第1の光を出力する第1反射面と、前記出射光を第2の軸に向けて前記第2の光を出力する第2反射面とを有し、前記第1の軸と前記第2の軸は互いに平行であり、かつ前記出射光の光軸とは異なってもよい。これにより平行な第1の光および第2の光を形成し、エタロンへの入射角を等しくすることができる。
(10)前記反射面は、前記出射光の一部を透過して第3の光を出力してもよい。エタロンを透過しない第3の光の強度を検出し、第3の光と第1の光との強度の比、および第3の光と第2の光との強度の比に基づいて波長制御を行う。
(11)波長可変レーザ素子と、前記波長可変レーザ素子の出射光を互いに平行な第1の光と第2の光とに分岐し出力するビームスプリッタと、前記第1の光および前記第2の光を透過するエタロンと、前記エタロンを通過した前記第1の光を受光する第1の検知部と、前記エタロンを通過した第2の光を受光する第2の検知部と、前記エタロンを通過する前の第2の光を受光する第3の検知部と、を具備する光半導体装置の制御方法であって、前記エタロンの前記第1の光に対する光路長は前記第2の光に対する光路長とは異なり、前記波長可変レーザ素子の出射光の目標波長に対応する駆動条件にて前記波長可変レーザ素子を駆動するステップと、前記第1の検知部および前記第2の検知部のうちいずれか一方の検知結果と前記第3の検知部の検知結果と用いて目標波長を選択するステップと、を含む光半導体装置の制御方法である。安定した波長制御が可能となる。
(12)前記波長可変レーザ素子の駆動情報を格納するメモリをさらに備える光半導体装置の制御方法であって、前記目標波長を選択するステップは、前記目標波長に基づいて前記メモリに格納されている前記第1の検知部および前記第2の検知部のいずれを用いるのか選択するステップを含んでもよい。これにより安定した波長制御が可能となる。
本開示の実施形態に係る光半導体装置およびその制御方法の具体例を、以下に図面を参照しつつ説明する。なお、本開示はこれらの例示に限定されるものではなく、請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。
図3は比較例1に係る光半導体装置100Rを例示する平面図である。図3に示すように、ビームスプリッタ21はビームスプリッタ20の+Y側に位置し、1つの反射面を有する。受光素子30はビームスプリッタ20の+Y側に位置し、ビームスプリッタ20を透過した光を受光する。エタロン24および受光素子26はビームスプリッタ21の+X側に位置し、光L1が入射する。
図5は比較例2に係る光半導体装置200Rを例示する平面図である。図5に示すように、ビームスプリッタ21の+X側にビームスプリッタ23が配置され、ビームスプリッタ23の+X側にエタロン24が配置され、+Y側にエタロン25が配置される。ビームスプリッタ23は、ビームスプリッタ21から出力される光を光L1およびL2に分岐する。受光素子26はエタロン24を透過した光L1を受光し、受光素子28はエタロン25を透過した光L2を受光する。
12 TEC
14 キャリア
16 波長可変レーザ素子
18 レンズフォルダ
20、21、22、23、42 ビームスプリッタ
22a、22b 反射面
24、25、44 エタロン
26、28、30 受光素子
32、34 偏光板
36 偏光反射板
40 可変偏光板
100、200、300、400、500 光半導体装置
Claims (12)
- 波長可変レーザ素子と、
前記波長可変レーザ素子の出射光を、互いに平行な第1の光と第2の光とに分岐し出力するビームスプリッタと、
前記第1の光および前記第2の光を透過するエタロンと、を具備し、
前記エタロンの前記第1の光に対する光路長は前記第2の光に対する光路長とは異なる光半導体装置。 - 前記エタロンは前記第1の光に対する光路長を画定する第1の部位と、前記第2の光に対する光路長を画定する第2の部位とを有し、
前記第1の部位の厚さは前記第2の部位の厚さとは異なる請求項1に記載の光半導体装置。 - 波長可変レーザ素子と、
前記波長可変レーザ素子の出射光を、第1の光と第2の光とに分岐し出力するビームスプリッタと、
前記第1の光および前記第2の光を透過するエタロンと、を具備し、
前記第1の光は前記エタロンへ第1の方向から入射し前記エタロン内で第1の光路を形成し、
前記第2の光は前記エタロンに前記第1の方向とは異なる第2の方向から入射し前記エタロン内で第2の光路を形成し、
前記第1の光路の光路長は前記第2の光路の光路長と異なる光半導体装置。 - 前記ビームスプリッタは第1の反射面と第2の反射面とを備え、
前記第1の反射面は前記出射光の一部を前記第1の光として前記第1の方向に出力し、前記第2の反射面は前記出射光の他の一部を前記第2の光として前記第2方向に出力する請求項3に記載の光半導体装置。 - 波長可変レーザ素子と、
前記波長可変レーザ素子の出射光を、第1の光と第2の光とに分岐し出力するビームスプリッタと、
前記第1の光および前記第2の光のうち少なくとも一方の偏波状態を変化させ、他方の偏波状態とは異ならせる偏光板と、
前記偏光板を通過した前記第1の光および前記第2の光を透過するエタロンと、を具備し、
前記エタロンは、前記エタロンに入射する光の偏波に対応して固有の屈折率を有する材料で構成されている光半導体装置。 - 前記偏光板は第1偏光板および第2偏光板を含み、
前記第1偏光板は前記第1の光の偏波状態を変化させ、前記第2偏光板は前記第2の光の偏波状態を前記第1の光とは異なる偏波状態に変化させる請求項5に記載の光半導体装置。 - 前記ビームスプリッタは前記出射光を反射する反射面を有し、
前記偏光板は前記反射面に設けられている請求項5または6に記載の光半導体装置。 - 前記エタロンは一様の厚さを有する請求項3から7のいずれか一項に記載の光半導体装置。
- 前記ビームスプリッタは、前記出射光を第1の軸に向けて前記第1の光を出力する第1反射面と、前記出射光を第2の軸に向けて前記第2の光を出力する第2反射面とを有し、
前記第1の軸と前記第2の軸は互いに平行であり、かつ前記出射光の光軸とは異なる請求項1、2、5から7のいずれか一項に記載の光半導体装置。 - 前記反射面は、前記出射光の一部を透過して第3の光を出力する請求項7または9に記載の光半導体装置。
- 波長可変レーザ素子と、前記波長可変レーザ素子の出射光を互いに平行な第1の光と第2の光とに分岐し出力するビームスプリッタと、前記第1の光および前記第2の光を透過するエタロンと、前記エタロンを通過した前記第1の光を受光する第1の検知部と、前記エタロンを通過した第2の光を受光する第2の検知部と、前記エタロンを通過する前の第2の光を受光する第3の検知部と、を具備する光半導体装置の制御方法であって、
前記エタロンの前記第1の光に対する光路長は前記第2の光に対する光路長とは異なり、
前記波長可変レーザ素子の出射光の目標波長に対応する駆動条件にて前記波長可変レーザ素子を駆動するステップと、
前記第1の検知部および前記第2の検知部のうちいずれか一方の検知結果と前記第3の検知部の検知結果とを用いて目標波長を選択するステップと、を含む光半導体装置の制御方法。 - 前記波長可変レーザ素子の駆動情報を格納するメモリをさらに備える光半導体装置の制御方法であって、
前記目標波長を選択するステップは、前記目標波長に基づいて前記メモリに格納されている前記第1の検知部および前記第2の検知部のいずれを用いるのか選択するステップを含む、請求項11に記載の光半導体装置の制御方法。
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1432088A1 (en) * | 2002-12-19 | 2004-06-23 | Agilent Technologies, Inc. - a Delaware corporation - | Semiconductor laser diode wavelength stabilisation |
JP2010034114A (ja) | 2008-07-25 | 2010-02-12 | Mitsubishi Electric Corp | レーザ装置、レーザモジュールおよび波長多重光通信システム |
JP2014165384A (ja) * | 2013-02-26 | 2014-09-08 | Furukawa Electric Co Ltd:The | 半導体レーザモジュール |
JP2015060961A (ja) * | 2013-09-19 | 2015-03-30 | 住友電気工業株式会社 | 波長制御システムおよび波長制御方法 |
US20170302051A1 (en) * | 2016-04-19 | 2017-10-19 | Lumentum Operations Llc | Wavelength locker using multiple feedback curves to wavelength lock a beam |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19743493C2 (de) * | 1997-10-01 | 2001-02-22 | Mueller Wirts Thomas | Verfahren und Vorrichtung zur Laserfrequenzmessung und -Stabilisierung |
US6233263B1 (en) * | 1999-06-04 | 2001-05-15 | Bandwidth9 | Monitoring and control assembly for wavelength stabilized optical system |
US6822979B2 (en) * | 2001-07-06 | 2004-11-23 | Intel Corporation | External cavity laser with continuous tuning of grid generator |
US6940879B2 (en) * | 2002-12-06 | 2005-09-06 | New Focus, Inc. | External cavity laser with dispersion compensation for mode-hop-free tuning |
TW594364B (en) * | 2003-07-23 | 2004-06-21 | Delta Electronics Inc | Wavelength stabilizing apparatus and control method |
US7327472B2 (en) * | 2004-07-23 | 2008-02-05 | Nusensors, Inc. | High temperature, minimally invasive optical sensing modules |
US20060050747A1 (en) * | 2004-09-08 | 2006-03-09 | Trutna William R Jr | Frequency-tunable light sources and methods of generating frequency-tunable light |
US7420686B2 (en) * | 2006-02-23 | 2008-09-02 | Picarro, Inc. | Wavelength measurement method based on combination of two signals in quadrature |
US7633624B1 (en) * | 2006-11-06 | 2009-12-15 | Itt Manufacturing Enterprises, Inc. | Self compensating cube corner interferometer |
-
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Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1432088A1 (en) * | 2002-12-19 | 2004-06-23 | Agilent Technologies, Inc. - a Delaware corporation - | Semiconductor laser diode wavelength stabilisation |
JP2010034114A (ja) | 2008-07-25 | 2010-02-12 | Mitsubishi Electric Corp | レーザ装置、レーザモジュールおよび波長多重光通信システム |
JP2014165384A (ja) * | 2013-02-26 | 2014-09-08 | Furukawa Electric Co Ltd:The | 半導体レーザモジュール |
JP2015060961A (ja) * | 2013-09-19 | 2015-03-30 | 住友電気工業株式会社 | 波長制御システムおよび波長制御方法 |
US20170302051A1 (en) * | 2016-04-19 | 2017-10-19 | Lumentum Operations Llc | Wavelength locker using multiple feedback curves to wavelength lock a beam |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2024095424A1 (ja) * | 2022-11-02 | 2024-05-10 | 三菱電機株式会社 | 波長ロッカー及び波長ロッカー内蔵型波長可変光源 |
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