Multi-wavelength light source device, chip and method

Abstract

The invention provides a multi-wavelength light source device, a multi-wavelength light source chip and a multi-wavelength light source method. The multi-wavelength light source device comprises a laser chip, a comb-shaped reflector and a photoelectric feedback loop composed of a photoelectric detector, a filter and an amplifier. The comb-shaped reflector is arranged behind a light outlet of the laser chip; the emergent frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of light is fed back to the laser chip to form a self-injection locking effect; by adjusting self-injection parameters, the laser chip generates multi-longitudinal-mode lasing, and the comb-shaped reflector excites stable longitudinal modes at several continuous reflection peaks of the comb-shaped reflector to form a multi-wavelength light source; beat frequency electric signals of a multi-wavelength light source are processed and then loaded to a laser chip in a current direct modulation mode, a photoelectric feedback loop is formed, and noise characteristic optimization of the multi-wavelength light source is further achieved. According to the embodiment of the invention, the system complexity is reduced, integration and miniaturization are facilitated, and the noise characteristic of the multi-wavelength light source can be improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a multi-wavelength light source device, chip and method. Background Art

[0002] Coherent multi-wavelength laser sources, which output multiple lasers with equal wavelength intervals at the same time, can be widely used in large-capacity dense wavelength division multiplexing optical communication systems, high-quality microwave local oscillator generation and microwave photonic communication systems (Radio Over Fiber, referred to as ROF). Multi-wavelength laser sources are used in dense wavelength division multiplexing coherent optical communication systems, which require that each wavelength of laser has a narrow linewidth, that is, a multi-wavelength narrow linewidth light source is used to replace multiple single-wavelength narrow linewidth lasers. Multi-wavelength laser sources are used in high-quality microwave local oscillator generation and ROF systems, which require that the frequency intervals of multiple wavelengths are stable and have good coherence with each other, that is, the microwave signal obtained by the multi-wavelength laser beat frequency has a stable frequency and low phase noise.

[0003] The key performance indicators of coherent multi-wavelength laser sources include: wavelength spacing, single-wave laser linewidth, frequency stability of beat frequency microwaves, and phase noise.

[0004] Existing methods for realizing multi-wavelength light sources mainly include mode-locked lasers and optoelectronic oscillators (OEO for short).

[0005] Mode-locked lasers insert a mode-locking device into the laser resonant cavity to ensure a certain phase relationship between longitudinal modes of different frequencies and to ensure the coherence of multiple longitudinal modes. Typical mode-locking devices include modulators (active mode-locking) and nonlinear saturated absorbers (passive mode-locking). Microcavity optical frequency combs can also be regarded as a self-mode-locked laser that relies on the nonlinearity of the waveguide itself.

[0006] The optoelectronic oscillator (OEO) converts light energy into microwave energy through an optoelectronic feedback loop, generating a microwave signal with extremely low phase noise. In the optical domain, the energy of the original single-wave laser is distributed to multiple equally spaced laser spectral lines through modulation, forming a multi-wavelength laser source.

[0007] The saturated absorber in the mode-locked laser needs a certain pulse power to be excited, which requires a sufficient number of laser spectral lines, resulting in too small intervals between multiple longitudinal mode wavelengths, making it unsuitable for application in wavelength division multiplexing optical communication systems; in addition, mode-locked devices such as saturated absorbers are generally difficult to integrate, making it difficult to miniaturize and integrate multi-wavelength light sources based on mode-locked lasers.

[0008] OEO uses the low-loss characteristics of optical fiber to increase the delay of the resonant cavity, thereby reducing the phase noise of the microwave oscillation signal. However, due to the introduction of a very long optical fiber delay, the longitudinal mode spacing in the cavity is very small, which is prone to mode hopping problems. In addition, the introduction of delay fiber also makes OEO very sensitive to environmental fluctuations and hinders the miniaturization and integration of OEO. Summary of the invention

[0009] The purpose of the embodiments of the present invention is to provide a multi-wavelength light source generating device, method, equipment and computer-readable storage medium to solve the problem that optoelectronic oscillators or mode-locked lasers in the prior art are difficult to simultaneously achieve miniaturization and integration while maintaining low noise.

[0010] In order to solve the above problems, an embodiment of the present invention provides a multi-wavelength light source device, including:

[0011] A laser chip, a comb-shaped reflector, and an optoelectronic feedback loop consisting of a photodetector, a filter, and an amplifier; wherein,

[0012] The comb-shaped reflector is arranged behind the light outlet of the laser chip, and the comb-shaped reflector and the laser chip are hybrid integrated; the laser chip is a single longitudinal mode or multi-longitudinal mode laser; the emission frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of the light is fed back to the laser chip to form a self-injection locking effect; by adjusting the self-injection parameters, the laser chip generates multi-longitudinal mode lasing;

[0013] The comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, and the longitudinal mode interval is consistent with the free spectrum range FSR of the reflection peak, forming a multi-wavelength light source;

[0014] The photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip, so as to optimize the coherence of the multi-wavelength light source.

[0015] The laser chip generates multi-longitudinal mode lasing by adjusting the self-injection parameters, including:

[0016] By adjusting the self-injection parameters, the self-pulsation phenomenon of the laser chip or the four-wave mixing phenomenon of the gain waveguide is triggered, so that the laser chip generates multi-longitudinal mode lasing;

[0017] Wherein, the self-injection parameters include the intensity and phase of the feedback light.

[0018] Wherein, when the FSR of the comb-shaped reflector is close to the photon-photon resonance frequency of the laser chip, the interval between adjacent longitudinal modes is consistent with the reflection peak FSR.

[0019] The output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, the output end of the filter is connected to the input end of the amplifier, and the output end of the amplifier is connected to the laser chip;

[0020] Among them, the multi-wavelength light source output by the comb reflector is input into the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter and sent to the amplifier for amplification, and then the amplified signal is fed back and loaded onto the laser chip by direct modulation.

[0021] The output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the filter, and the output end of the filter is connected to the laser chip;

[0022] The multi-wavelength light source output by the comb reflector is input into the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is sent to the amplifier for amplification, and the amplified signal is sent to the filter to be filtered out and then fed back to the laser chip through direct modulation.

[0023] The output end of the comb-shaped reflector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, and the output end of the filter is connected to the laser chip;

[0024] The multi-wavelength light source output by the comb reflector is sent to the amplifier for light amplification, and the amplified multi-wavelength light source is input to the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter, and then fed back and loaded onto the laser chip by direct modulation.

[0025] By reducing the feedback bandwidth of the comb-shaped reflector, the single-wavelength output line width of the multi-wavelength light source is reduced, and the delay of the photoelectric feedback loop is increased.

[0026] The embodiment of the present invention further provides a method for generating a multi-wavelength light source, which is performed by the multi-wavelength light source device as described above, and the method includes:

[0027] Adjusting the self-injection parameters of the laser chip and the comb-shaped reflector so that the laser chip generates multi-longitudinal mode lasing;

[0028] The comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, and the longitudinal mode interval is consistent with the FSR of the reflection peaks, forming a multi-wavelength light source;

[0029] The photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip, so as to optimize the coherence of the multi-wavelength light source.

[0030] Wherein, the method further comprises:

[0031] By reducing the feedback bandwidth of the comb-shaped reflector, the single-wavelength output line width of the multi-wavelength light source is reduced, and the delay of the photoelectric feedback loop is increased.

[0032] An embodiment of the present invention further provides a chip, comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor implements the multi-wavelength light source generating method as described above when executing the program.

[0033] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps in the multi-wavelength light source generating method as described above.

[0034] The above technical solution of the present invention has at least the following beneficial effects:

[0035] In the multi-wavelength light source device, chip and method of the embodiment of the present invention, the multi-wavelength light source device includes a laser chip, a comb-shaped reflector and a photoelectric feedback loop composed of a photodetector, a filter and an amplifier. The comb-shaped reflector is used to introduce a self-injection locking effect to the laser, and the self-pulsation phenomenon is induced in the laser by adjusting the self-injection feedback parameters, thereby generating multi-longitudinal mode oscillations. Due to the introduction of the self-injection locking effect, the direct modulation bandwidth of the laser is enhanced, the direct modulation chirp is weakened, and the performance improvement brought by the self-injection locking makes the direct modulation performance of the laser very close to the external modulation performance using a modulator. Therefore, laser direct modulation can be used to replace the modulator, which not only reduces the complexity of the system, but also is more conducive to integration and miniaturization, and can also improve the noise characteristics of the multi-wavelength light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram showing the structure of a multi-wavelength light source device provided by an embodiment of the present invention;

[0037] Figure 2 It represents the periodic reflection characteristics of the comb-shaped reflector in the multi-wavelength light source device provided by the embodiment of the present invention;

[0038] Figure 3It represents the multi-longitudinal mode lasing generated by the self-pulsation phenomenon introduced by the self-injection feedback in the multi-wavelength light source device provided by the embodiment of the present invention;

[0039] Figure 4 A schematic diagram showing a flow chart of a method for generating a multi-wavelength light source provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram showing the structure of Example 1 provided in an embodiment of the present invention;

[0041] Figure 6 A diagram showing experimental test results of Example 1 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1 As shown, an embodiment of the present invention provides a multi-wavelength light source device, including:

[0044] A laser chip, a comb-shaped reflector, and an optoelectronic feedback loop consisting of a photodetector, a filter, and an amplifier; wherein,

[0045] The comb-shaped reflector is arranged behind the light outlet of the laser chip, and the comb-shaped reflector and the laser chip are hybrid integrated; the laser chip is a single longitudinal mode or multi-longitudinal mode laser; the emission frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of the light is fed back to the laser chip to form a self-injection locking effect; by adjusting the self-injection parameters, the laser chip generates multi-longitudinal mode lasing;

[0046] The comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, and the longitudinal mode interval is consistent with the free spectrum range FSR of the reflection peak, forming a multi-wavelength light source;

[0047] The photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip, so as to optimize the coherence of the multi-wavelength light source.

[0048] The comb-shaped reflector is arranged behind the light outlet of the laser chip and has a periodic reflection characteristic in the frequency domain (the frequency interval between adjacent reflection peaks is called the free spectral range, i.e., Free Spectral Range, which can be abbreviated as FSR, such as Figure 2 The implementation methods of the comb reflector include but are not limited to a micro-ring resonator, a FP resonator, a grating and their combined structures.

[0049] Optionally, the laser chip is a DFB (Distributed Feedback Laser) laser or a FP (Fabry-Perot) laser.

[0050] The comb-shaped reflector and the laser chip are hybrid integrated, for example, by waveguide edge direct alignment coupling, wafer-bonding, micro-transfer technology, micro-optical coupling, photonic waveguide leads, etc.

[0051] Optionally, adjusting the self-injection parameters so that the laser chip generates multi-longitudinal mode lasing includes: adjusting the self-injection parameters to trigger the self-pulsation phenomenon of the laser chip or the four-wave mixing phenomenon of the gain waveguide so that the laser chip generates multi-longitudinal mode lasing;

[0052] Wherein, the self-injection parameters include the intensity and phase of the feedback light.

[0053] The emission frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of the light is fed back to the laser chip to form a self-injection locking effect; at this time, the emission frequency of the laser chip is locked on the reflection peak of the comb filter. The self-pulsation phenomenon of the laser chip is triggered by adjusting the self-injection parameters, so that the laser chip is converted from single-mode lasing to multi-longitudinal mode lasing; for example, the self-injection parameters include: feedback phase, frequency offset between the laser and the reflection peak, etc. The self-injection parameters can be adjusted by adjusting the laser temperature, injection current, and reflector temperature. Optionally, the self-pulsation phenomenon is induced by periodic feedback from the external cavity, and the self-pulsation frequency is the external cavity feedback period frequency or an integer multiple thereof.

[0054] The embodiment of the present invention uses a comb-shaped reflector to introduce a self-injection locking effect to a laser, and adjusts the self-injection feedback parameters to induce the laser to generate a self-pulsation phenomenon, thereby generating multi-longitudinal mode oscillations.

[0055] Optionally, when the FSR of the comb-shaped reflector is close to the photon-photon resonance frequency of the laser chip, the interval between adjacent longitudinal modes is consistent with the reflection peak FSR.

[0056] like Figure 3As shown, when the free spectral range FSR of the comb reflector is close to the photon-photon resonance frequency of the laser chip, the comb reflector stably excites stable longitudinal modes at adjacent reflection peaks, and the longitudinal mode interval is consistent with the reflection peak FSR, outputting a multi-wavelength light source. The FSR of the comb filter in the embodiment of the present invention is close to the photon-photon resonance frequency of the self-injection locked laser through structural design, thereby stably exciting multiple longitudinal modes at adjacent reflection peaks, ensuring that the longitudinal mode interval is equal to the FSR.

[0057] Due to the introduction of the self-injection locking effect in the embodiment of the present invention, the direct modulation bandwidth of the laser is enhanced and the direct modulation chirp is weakened. The performance improvement brought about by the self-injection locking makes the direct modulation performance of the laser very close to the external modulation performance using a modulator. Therefore, the laser direct modulation can be used to replace the modulator, which not only reduces the complexity of the system, but also is more conducive to integration and miniaturization; and the self-injection effect makes the frequency of the laser locked on the reflection peak of the comb reflector, and by controlling the generation of the self-pulsation phenomenon, the stable longitudinal mode is excited on the adjacent reflection peak, which makes the frequency interval of the multi-longitudinal mode spectrum equal to the FSR of the comb reflector. Since the FSR of the comb reflector is only related to the chip itself and is very insensitive to environmental changes, this makes the longitudinal mode interval of multiple wavelengths very stable.

[0058] The embodiment of the present invention adopts a photoelectric feedback loop to further optimize the coherence of the multi-wavelength light source. By using the photoelectric feedback loop to directly modulate the beat frequency microwave signal and load it onto the laser, the coherence of the multi-wavelength light source is greatly improved, and the frequency stability and phase noise of the beat frequency microwave signal are optimized by 2 and 4 orders of magnitude respectively.

[0059] As an optional embodiment, Figure 1 As shown, the output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, the output end of the filter is connected to the input end of the amplifier, and the output end of the amplifier is connected to the laser chip;

[0060] The multi-wavelength light source output by the comb reflector is input to the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter and sent to the amplifier for amplification, and then the amplified signal is fed back to the laser chip by direct modulation. Through this photoelectric feedback loop, the phase noise and frequency stability of the beat frequency microwave signal can be greatly optimized. It should be noted that the amplification of the amplifier in this embodiment is electrical amplification.

[0061] As another optional embodiment, the output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the filter, and the output end of the filter is connected to the laser chip;

[0062] The multi-wavelength light source output by the comb reflector is input to the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component of the beat frequency microwave signal with a frequency equal to FSR is sent to the amplifier for amplification, and the amplified signal is sent to the filter to be filtered out and then fed back to the laser chip by direct modulation. It should be noted that the amplification of the amplifier in this embodiment is electrical amplification.

[0063] As another optional embodiment, the output end of the comb-shaped reflector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, and the output end of the filter is connected to the laser chip;

[0064] The multi-wavelength light source output by the comb reflector is sent to the amplifier for optical amplification, and the amplified multi-wavelength light source is input to the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter, and then fed back to the laser chip by direct modulation. It should be noted that the amplification of the amplifier in this embodiment is optical amplification, for example, the amplifier uses an erbium-doped fiber amplifier.

[0065] In at least one embodiment of the present invention, by reducing the feedback bandwidth of the comb-shaped reflector (increasing the feedback delay), reducing the single-wavelength output line width of the multi-wavelength light source, and increasing the delay of the photoelectric feedback loop, it is easier to integrate. In addition, by using a narrow-band comb-shaped reflector, a longer optical fiber delay can be replaced, which is easier to integrate.

[0066] In summary, the multi-wavelength light source device in the embodiment of the present invention includes a laser chip, a comb-shaped reflector, a photodetector, a filter and an amplifier. The comb-shaped reflector is used to introduce a self-injection locking effect to the laser, and the self-pulsation phenomenon is induced in the laser by adjusting the self-injection feedback parameter, thereby generating multi-longitudinal mode oscillations; due to the introduction of the self-injection locking effect, the direct modulation bandwidth of the laser is enhanced, and the direct modulation chirp is weakened. The performance improvement brought by the self-injection locking makes the direct modulation performance of the laser very close to the external modulation performance using a modulator. Therefore, the laser direct modulation can be used to replace the modulator, which not only reduces the complexity of the system, but also is more conducive to integration and miniaturization; and the self-injection effect makes the frequency of the laser locked on the reflection peak of the comb-shaped reflector, and by controlling the generation of the self-pulsation phenomenon / four-wave mixing, the stable longitudinal mode is excited on the adjacent reflection peak, which makes the frequency interval of the multi-longitudinal mode spectrum equal to the FSR of the comb-shaped reflector. Since the FSR of the comb-shaped reflector is only related to the chip itself and is very insensitive to environmental changes, this makes the longitudinal mode interval of the multi-wavelength very stable.

[0067] The multi-wavelength coherent light source in this technical solution can be directly applied to optical modules, and has product application prospects in the fields of wireless over fiber (ROF) systems, highly integrated dense wavelength division coherent optical communication systems, and distributed high-frequency microwave local oscillator generation.

[0068] like Figure 4 As shown, an embodiment of the present invention further provides a method for generating a multi-wavelength light source, which is performed by the multi-wavelength light source generating device as described above, and the method includes:

[0069] Step 401, adjusting the self-injection parameters of the laser chip and the comb-shaped reflector so that the laser chip generates multi-longitudinal mode lasing;

[0070] Step 402, the comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, wherein the longitudinal mode interval is consistent with the FSR of the reflection peaks, thereby forming a multi-wavelength light source;

[0071] Step 403: the photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip to optimize the coherence of the multi-wavelength light source.

[0072] In the embodiment of the present invention, the comb-shaped reflector is arranged behind the light outlet of the laser chip and has a periodic reflection characteristic in the frequency domain (the frequency spacing between adjacent reflection peaks is called the free spectral range, i.e., Free Spectral Range, which can be referred to as FSR, such as Figure 2 The implementation methods of the comb reflector include but are not limited to a micro-ring resonator, a FP resonator, a grating and their combined structures.

[0073] The comb-shaped reflector and the laser chip are hybrid integrated, for example, by waveguide edge direct alignment coupling, wafer-bonding, micro-transfer technology, micro-optical coupling, photonic waveguide leads, etc.

[0074] Optionally, adjusting the self-injection parameters so that the laser chip generates multi-longitudinal mode lasing includes: adjusting the self-injection parameters to trigger the self-pulsation phenomenon of the laser chip or the four-wave mixing phenomenon of the gain waveguide so that the laser chip generates multi-longitudinal mode lasing;

[0075] Wherein, the self-injection parameters include the intensity and phase of the feedback light.

[0076] The emission frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of the light is fed back to the laser chip to form a self-injection locking effect; at this time, the emission frequency of the laser chip is locked on the reflection peak of the comb filter. The self-pulsation phenomenon of the laser chip is triggered by adjusting the self-injection parameters, so that the laser chip is converted from single-mode lasing to multi-longitudinal mode lasing; for example, the self-injection parameters include: feedback phase, frequency offset between the laser and the reflection peak, etc. The self-injection parameters can be adjusted by adjusting the laser temperature, injection current, and reflector temperature. Optionally, the self-pulsation phenomenon is induced by periodic feedback from the external cavity, and the self-pulsation frequency is the external cavity feedback period frequency or an integer multiple thereof.

[0077] The embodiment of the present invention uses a comb-shaped reflector to introduce a self-injection locking effect to a laser, and adjusts the self-injection feedback parameters to induce the laser to generate a self-pulsation phenomenon, thereby generating multi-longitudinal mode oscillations.

[0078] like Figure 3 As shown, when the free spectral range FSR of the comb reflector is close to the photon-photon resonance frequency of the laser chip, the comb reflector stably excites stable longitudinal modes at adjacent reflection peaks, and the longitudinal mode interval is consistent with the reflection peak FSR, outputting a multi-wavelength light source. The FSR of the comb filter in the embodiment of the present invention is close to the photon-photon resonance frequency of the self-injection locked laser through structural design, thereby stably exciting multiple longitudinal modes at adjacent reflection peaks, ensuring that the longitudinal mode interval is equal to the FSR.

[0079] Due to the introduction of the self-injection locking effect in the embodiment of the present invention, the direct modulation bandwidth of the laser is enhanced and the direct modulation chirp is weakened. The performance improvement brought about by the self-injection locking makes the direct modulation performance of the laser very close to the external modulation performance using a modulator. Therefore, the laser direct modulation can be used to replace the modulator, which not only reduces the complexity of the system, but also is more conducive to integration and miniaturization; and the self-injection effect makes the frequency of the laser locked on the reflection peak of the comb reflector, and by controlling the generation of the self-pulsation phenomenon, the stable longitudinal mode is excited on the adjacent reflection peak, which makes the frequency interval of the multi-longitudinal mode spectrum equal to the FSR of the comb reflector. Since the FSR of the comb reflector is only related to the chip itself and is very insensitive to environmental changes, this makes the longitudinal mode interval of multiple wavelengths very stable.

[0080] The embodiment of the present invention adopts a photoelectric feedback loop to further optimize the coherence of the multi-wavelength light source. By using the photoelectric feedback loop to directly modulate the beat frequency microwave signal and load it onto the laser, the coherence of the multi-wavelength light source is greatly improved, and the frequency stability and phase noise of the beat frequency microwave signal are optimized by 2 and 4 orders of magnitude respectively.

[0081] In at least one embodiment of the present invention, by reducing the feedback bandwidth of the comb-shaped reflector (increasing the feedback delay), reducing the single-wavelength output line width of the multi-wavelength light source, and increasing the delay of the photoelectric feedback loop, it is easier to integrate. In addition, by using a narrow-band comb-shaped reflector, a longer optical fiber delay can be replaced, which is easier to integrate.

[0082] In summary, the multi-wavelength light source generating device in the embodiment of the present invention includes a laser chip, a comb-shaped reflector, a photodetector, a filter and an amplifier. The comb-shaped reflector is used to introduce a self-injection locking effect to the laser, and the self-pulsation phenomenon is induced in the laser by adjusting the self-injection feedback parameter, thereby generating multi-longitudinal mode oscillations; due to the introduction of the self-injection locking effect, the direct modulation bandwidth of the laser is enhanced, and the direct modulation chirp is weakened. The performance improvement brought by the self-injection locking makes the direct modulation performance of the laser very close to the external modulation performance using a modulator. Therefore, the laser direct modulation can be used to replace the modulator, which not only reduces the complexity of the system, but also is more conducive to integration and miniaturization; and the self-injection effect makes the frequency of the laser locked on the reflection peak of the comb-shaped reflector, and by controlling the generation of the self-pulsation phenomenon, the stable longitudinal mode is excited on the adjacent reflection peak, which makes the frequency interval of the multi-longitudinal mode spectrum equal to the FSR of the comb-shaped reflector. Since the FSR of the comb-shaped reflector is only related to the chip itself and is very insensitive to environmental changes, this makes the longitudinal mode interval of the multi-wavelength very stable.

[0083] In order to more clearly describe the multi-wavelength light source generating device and method provided by the embodiments of the present invention, an example is provided below for illustration.

[0084] Example 1

[0085] like Figure 5 As shown, the laser uses a DFB semiconductor laser chip with an emission wavelength of around 1550nm. The comb-shaped reflector is a combination of a micro-ring resonator and a grating. The micro-ring provides a periodic filtering function and the grating provides a reflection function. This structure is implemented on a Si3N4 waveguide chip platform. The FSR of the frequency domain reflection peak is determined to be 0.1nm (~12.5GHz) by designing the circumference of the micro-ring. The grating reflects a 10nm frequency band around 1550nm to ensure that the wavelength generation range of the multi-wavelength laser is sufficiently covered. The DFB chip and the Si3N4 reflector chip are hybrid integrated by direct alignment coupling of the waveguide edge to form a hybrid integrated laser.

[0086] The temperature of the DFB chip is adjusted to stimulate the self-pulsation phenomenon of the hybrid integrated laser, so that stable multi-longitudinal mode lasing is generated at adjacent reflection peaks. At this time, the self-pulsation frequency is the same as the FSR of the microring.

[0087] The multi-longitudinal mode output light of the hybrid integrated laser is sent into the detector to obtain a microwave signal by beating frequency, and the component with a frequency equal to FSR is filtered out by a bandpass filter and amplified by a low-noise amplifier (the gain needs to be able to compensate for the loss of the microwave photonic link).

[0088] Finally, the amplified microwave signal and the DC drive current are coupled together through a T-type bias breaker and loaded onto the DFB. The microwave signal is fed back to the laser through direct modulation, forming a complete closed optoelectronic feedback loop.

[0089] like Figure 6 The figure shows the experimental test results of the measured spectrum, electrical spectrum, frequency stability and phase noise of the multi-wavelength light source generating device provided by the embodiment of the present invention. Among them, the multi-wavelength laser spectrum lines are equally spaced, and the frequency interval is about 12.33GHz, which is equal to the FSR of the microring. In the case of a photoelectric feedback loop, the frequency stability is 10kHz@5min. Compared with the case without photoelectric feedback, the frequency stability is improved by 2 orders of magnitude. When the photoelectric feedback loop is turned on, the phase noise of the multi-wavelength beat frequency microwave signal is as low as -91.3dBc@10kHz, which is 4 orders of magnitude better than the case without photoelectric feedback. The above experimental results verify the feasibility and performance advantages of the invention scheme.

[0090] An embodiment of the present invention further provides a chip, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, each process in the embodiment of the multi-wavelength light source generating method as described above is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0091] The embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, each process in the embodiment of the multi-wavelength light source generation method described above is implemented, and the same technical effect can be achieved. To avoid repetition, it is not repeated here. The computer-readable storage medium is, for example, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0092] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0093] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A device that specifies functions in one or more processes and / or one or more blocks.

[0094] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable storage medium produce a paper product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0095] These computer program instructions may also be loaded onto a computer or other programmable data processing device to cause the computer or other programmable device to execute a series of operating steps to produce a computer-implemented process, thereby providing instructions executed on the computer or other programmable device for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0096] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-wavelength light source device, characterized in that: include: A laser chip, a comb-shaped reflector, and an optoelectronic feedback loop consisting of a photodetector, a filter, and an amplifier; wherein, The comb-shaped reflector is arranged behind the light outlet of the laser chip, and the comb-shaped reflector and the laser chip are hybrid integrated; the laser chip is a single longitudinal mode or multi-longitudinal mode laser; the emission frequency of the laser chip is aligned with the reflection peak of the comb-shaped reflector, and part of the light is fed back to the laser chip to form a self-injection locking effect; by adjusting the self-injection parameters, the laser chip generates multi-longitudinal mode lasing; The comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, and the longitudinal mode interval is consistent with the free spectrum range FSR of the reflection peak, forming a multi-wavelength light source; The photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip, so as to optimize the coherence of the multi-wavelength light source.

2. The device according to claim 1, characterized in that By adjusting the self-injection parameters, the laser chip generates multi-longitudinal mode lasing, including: By adjusting the self-injection parameters, the self-pulsation phenomenon of the laser chip or the four-wave mixing phenomenon of the gain waveguide is triggered, so that the laser chip generates multi-longitudinal mode lasing; Wherein, the self-injection parameters include the intensity and phase of the feedback light.

3. The device according to claim 1, characterized in that When the FSR of the comb-shaped reflector is close to the photon-photon resonance frequency of the laser chip, the interval between adjacent longitudinal modes is consistent with the reflection peak FSR.

4. The device according to claim 1, characterized in that The output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, the output end of the filter is connected to the input end of the amplifier, and the output end of the amplifier is connected to the laser chip; Among them, the multi-wavelength light source output by the comb reflector is input into the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter and sent to the amplifier for amplification, and then the amplified signal is fed back and loaded onto the laser chip by direct modulation.

5. The device according to claim 1, characterized in that The output end of the comb-shaped reflector is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the filter, and the output end of the filter is connected to the laser chip; The multi-wavelength light source output by the comb reflector is input into the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is sent to the amplifier for amplification, and the amplified signal is sent to the filter to be filtered out and then fed back to the laser chip through direct modulation.

6. The device according to claim 1, characterized in that The output end of the comb-shaped reflector is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the photodetector, the output end of the photodetector is connected to the input end of the filter, and the output end of the filter is connected to the laser chip; The multi-wavelength light source output by the comb reflector is sent to the amplifier for light amplification, and the amplified multi-wavelength light source is input to the photodetector to obtain a beat frequency microwave signal; the single-frequency AC component with a frequency equal to FSR in the beat frequency microwave signal is filtered out by the filter, and then fed back and loaded onto the laser chip by direct modulation.

7. The device according to any one of claims 1 to 6, characterized in that: By reducing the feedback bandwidth of the comb-shaped reflector, the single-wavelength output line width of the multi-wavelength light source is reduced, and the delay of the photoelectric feedback loop is increased.

8. A method for generating a multi-wavelength light source, characterized in that: The method is performed by the multi-wavelength light source device according to any one of claims 1 to 7, and comprises: Adjusting the self-injection parameters of the laser chip and the comb-shaped reflector so that the laser chip generates multi-longitudinal mode lasing; The comb-shaped reflector stably excites stable longitudinal modes at a plurality of adjacent reflection peaks, and the longitudinal mode interval is consistent with the FSR of the reflection peaks, forming a multi-wavelength light source; The photoelectric feedback loop directly modulates the beat frequency microwave signal output by the photoelectric detector and loads it onto the laser chip, so as to optimize the coherence of the multi-wavelength light source.

9. The method according to claim 8, characterized in that The method further comprises: By reducing the feedback bandwidth of the comb-shaped reflector, the single-wavelength output line width of the multi-wavelength light source is reduced, and the delay of the photoelectric feedback loop is increased.

10. A chip comprising a memory, a processor, and a program stored in the memory and executable on the processor; characterized in that: When the processor executes the program, the multi-wavelength light source generating method as claimed in claim 8 or 9 is implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in the method for generating a multi-wavelength light source as claimed in claim 8 or 9 are implemented.

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