CN-122000791-A - High-coherence parallel light source generating device and method

Abstract

The disclosure provides a generation device and a generation method of a high-coherence parallel light source, and relates to the field of lasers. The device comprises a generation unit of a narrow linewidth optical frequency comb, a wavelength division multiplexing unit and a low-noise high-gain amplification unit, wherein the generation unit comprises a first distributed feedback type laser and a micro-ring resonant cavity, output light of the first distributed feedback type laser is coupled into the micro-ring resonant cavity, narrow linewidth laser is generated through a self-injection locking mechanism, the nonlinear effect of the micro-ring resonant cavity is utilized to convert the narrow linewidth laser into the optical frequency comb with a plurality of comb teeth, the wavelength division multiplexing unit is used for carrying out wavelength separation on the plurality of comb teeth of the optical frequency comb to form a plurality of single-wavelength optical comb teeth, and the low-noise high-gain amplification unit is used for injecting and locking the optical comb teeth of each single-wavelength optical comb into a second distributed feedback type laser to generate a high-coherence parallel light source. The method can meet the application requirements of future integrated photonics in a large-scale high-parallelism coherent system, and can generate a high-power, high-conversion-efficiency and flat multi-wavelength light source which is easy to integrate and has high coherence.

Inventors

• CHANG LIN
• ZHANG XUGUANG
• ZHOU ZIXUAN

Assignees

• 北京大学

Dates

Publication Date

20260508

Application Date

20241105

Claims (10)

1. 1. A generation device of a high coherence parallel light source, comprising: The generating unit (1) of the narrow linewidth optical frequency comb comprises a first distributed feedback laser (DFB 1) and a micro-ring resonant cavity (MRR), wherein output light of the first distributed feedback laser (DFB 1) is coupled into the micro-ring resonant cavity (MRR) to generate narrow linewidth laser through a self-injection locking mechanism; A wavelength division multiplexing unit (DEMUX) for performing wavelength separation on the plurality of comb teeth of the optical frequency comb to form a plurality of optical comb teeth with single wavelength; And the low-noise high-gain amplifying unit (2) is used for injecting and locking each single-wavelength optical comb tooth into the second distributed feedback laser (DFB 2) to generate a high-coherence parallel light source.
2. 2. The generating device according to claim 1, characterized in that the first distributed feedback laser (DFB 1) and the micro-ring resonator (MRR) are integrated or coupled.
3. 3. The generating device of claim 1, wherein the wavelength-division-multiplexing unit (DEMUX) comprises a thin film filter, an arrayed waveguide grating, and a fiber bragg grating.
4. 4. The generating device according to claim 1, characterized in that said low noise high gain amplifying unit (2) further comprises a circulator (circle) for injecting each of said single wavelength optical comb teeth into the front facet of said second distributed feedback laser (DFB 2); the low-noise high-gain amplifying unit (2) also injects each single-wavelength optical comb tooth into the back cavity surface of the second distributed feedback laser (DFB 2).
5. 5. The generating device of claim 1, wherein the generating device further comprises: and the wavelength division Multiplexer (MUX) is used for combining the optical comb teeth with the injection-locked multiple different wavelengths to form a high-coherence parallel light source.
6. 6. A method of generating a high coherence parallel light source, comprising: Step S1, coupling output light of a first distributed feedback laser into a micro-ring resonant cavity through a self-injection locking mechanism to generate narrow linewidth laser, and converting the narrow linewidth laser into an optical frequency comb with a plurality of comb teeth by utilizing a nonlinear effect of the micro-ring resonant cavity; Step S2, performing wavelength separation on each comb tooth of the optical frequency comb to form a plurality of optical comb teeth with single wavelength; and S3, injecting and locking the second distributed feedback laser merging beam by each single-wavelength optical comb tooth to generate a high-coherence parallel light source.
7. 7. The method of generating according to claim 6, wherein in step S1, the generation of the optical frequency comb and the narrowing of the line width are achieved by any one of the following means: Adjusting a drive current of the first distributed feedback laser; when the first distributed feedback laser is coupled with the micro-ring resonant cavity, adjusting the distance between the first distributed feedback laser and the micro-ring resonant cavity; And when the first distributed feedback laser and the micro-ring resonant cavity are integrated through a bus waveguide, tuning the phase on the bus waveguide.
8. 8. The method of claim 6, wherein in step S1, the first distributed feedback laser and the micro-ring resonator are both placed on a temperature console.
9. 9. The method according to claim 6, wherein the step S3 includes: Injecting each single-wavelength optical comb tooth into the front cavity surface of the second distributed feedback laser through a circulator, or And injecting each single-wavelength optical comb tooth into the back cavity surface of the second distributed feedback laser.
10. 10. The method according to claim 6, wherein the step S3 further comprises: And combining the optical comb teeth with different wavelengths after injection locking through a wavelength division multiplexer to form a high-coherence parallel light source.

Description

High-coherence parallel light source generating device and method Technical Field The disclosure relates to the field of lasers, and in particular relates to a device and a method for generating a high-coherence parallel light source. Background Coherent optics has profound effects on applications such as optical communications, lidar, optical computing, light quanta, optical sensing, and imaging. For example, in optical communication, coherent detection has better noise suppression and anti-interference capabilities, has smaller error rate, and can improve the data transmission rate through a high-order modulation format. In lidar, coherent techniques enable more rapid and accurate measurement of object distance and velocity. The coherence technology can also ensure high fidelity of light quanta, generate large-scale entanglement, and improve the precision and parallelism of light quanta calculation. Currently, a major trend in integrated photonics is to employ coherent technology to meet the ever-increasing capacity and accuracy requirements. However, the development of coherent systems in integrated optics requires a tremendous cost in terms of hardware integration and energy efficiency. In particular in terms of light sources, there has been no method so far that can strike a balance between high parallelism, high coherence and high power at the same time. The most commonly used on-chip light source, group III-V first distributed feedback laser (DFB 1), is excellent in power and electro-optic conversion efficiency, but its inherent linewidth is typically at the level of 100 kHz, which is difficult to meet the coherence requirements for many applications. To improve coherence, methods of coupling III-V lasers to high quality factor (Q) resonators are commonly employed, which can effectively reduce linewidths to sub-khz levels, but at the same time sacrifice power and electro-optic conversion efficiency. High Q resonators are also used to generate optical frequency combs to produce parallel light sources, but nonlinear frequency conversion processes typically have only a few percent of the light-to-light conversion efficiency, further limiting channel power. For an integrated microcavity optical frequency comb, the existing scheme has the problems of low comb tooth power and low wall insertion efficiency, and cannot be directly used as a light source in a coherent light system. And the amplification of the comb power by the erbium-doped fiber amplifier and the semiconductor optical amplifier introduces additional noise, thereby greatly impairing the performance of the coherent optical system. Disclosure of Invention In view of the foregoing, the present disclosure provides a generation apparatus and method of a high-coherence parallel light source, which implements the high-coherence parallel light source in an advanced integrated coherence system at a minimum cost. The device comprises a generation unit of a narrow-linewidth optical frequency comb, a wavelength division multiplexing unit and a low-noise high-gain amplification unit, wherein the generation unit comprises a first distributed feedback type laser and a micro-ring resonant cavity, output light of the first distributed feedback type laser is coupled into the micro-ring resonant cavity, narrow-linewidth laser is generated through a self-injection locking mechanism, the nonlinear effect of the micro-ring resonant cavity is utilized to convert the narrow-linewidth laser into the optical frequency comb with a plurality of comb teeth, the wavelength division multiplexing unit is used for carrying out wavelength separation on the plurality of comb teeth of the optical frequency comb to form a plurality of single-wavelength optical comb teeth, and the low-noise high-gain amplification unit is used for injecting and locking the optical comb teeth of each single-wavelength optical comb into a second distributed feedback type laser to generate the high-coherence parallel light source. According to embodiments of the present disclosure, a first distributed feedback laser is integrated with or coupled to a micro-ring resonator. According to an embodiment of the present disclosure, the wavelength-division-multiplexing unit includes a thin film filter, an arrayed waveguide grating, and a fiber bragg grating. According to the embodiment of the disclosure, the low-noise high-gain amplifying unit further comprises a circulator, wherein the circulator is used for injecting each single-wavelength optical comb tooth into the front cavity surface of the second distributed feedback laser, and the low-noise high-gain amplifying unit further injects each single-wavelength optical comb tooth into the rear cavity surface of the second distributed feedback laser. According to the embodiment of the disclosure, the generating device further comprises a wavelength division multiplexer, which is used for combining the optical comb teeth with the injection-locked multiple di