Brillouin semiconductor laser

Abstract

The invention relates to the technical field of laser devices, in particular to a Brillouin semiconductor laser device which comprises a gain chip, a Brillouin semiconductor laser device and a Brillouin semiconductor laser device, a Bragg grating; a microring resonator; the beam splitter is located between the micro-ring resonator and the Bragg grating; wherein the gain chip is used for generating spontaneous radiation light, the Bragg grating and the high-reflection film form a resonant cavity, the spontaneous radiation light is processed by the resonant cavity to form pump light, the pump light is injected into the micro-ring resonator through a second end of the Bragg grating, the micro-ring resonator generates a stimulated Brillouin scattering effect to generate Stokes light, and the Stokes light is transmitted to the high-reflection film. The micro-ring resonator carries out mode selection amplification on the Stokes light, ultra-narrow linewidth Brillouin laser is output from the first end of the micro-ring resonator, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset proportion. According to the Brillouin semiconductor laser, the integration level and the compactness of the Brillouin semiconductor laser are improved while it is guaranteed that the Brillouin semiconductor laser has excellent performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and particularly relates to a Brillouin semiconductor laser. Background Art

[0002] Semiconductor lasers play a crucial role in the field of atomic detection, especially in high-precision spectroscopic analysis and quantum manipulation. These applications require laser light sources to have ultra-narrow linewidth, high coherence, and low noise characteristics to ensure precise atomic state manipulation and detection efficiency. In the field of generating ultra-narrow linewidth lasers, stimulated Brillouin scattering (SBS) has been proven to be an effective method for achieving high-purity spectral output. The stimulated Brillouin scattering effect is an important nonlinear optical phenomenon, which refers to the light scattering phenomenon generated by the interaction between the light wave incident on the optical medium and the elastic acoustic wave in the medium. Since the statistical thermal motion of a large number of particles in the optical medium will generate elastic acoustic waves, it will cause the density of the optical medium to change periodically with time and space, so that the refractive index of the optical medium also changes periodically with time and space. Therefore, the acoustic vibration medium can be regarded as a moving grating. In this way, when a light wave with a frequency of ω passes through the optical medium, a coherent acoustic wave with a frequency of ω s will be generated in the optical medium, and at the same time, a scattered light wave with a frequency of (ω - ω s ) will be generated, that is, Stokes light. The acoustic wave and Stokes light propagate along a specific direction, and the above phenomenon can only occur when the intensity of the incident light exceeds a certain value. This kind of Brillouin scattering with stimulated emission characteristics is called stimulated Brillouin scattering. For stimulated Brillouin scattering, the phase noise of the pump light will be greatly suppressed under the combined action of cavity feedback and phonon oscillation, and only a small part will be transferred to the phase of the Stokes light. Therefore, the linewidth of the output Brillouin laser will be greatly suppressed.

[0003] Traditionally, Brillouin semiconductor lasers mainly generate Brillouin lasers through the stimulated Brillouin scattering effect based on erbium-doped fiber amplifiers (EDFAs) and specific waveguide structures. The specific waveguide structures can be chalcogenide glass waveguides (for example, As2S3 waveguides) or silicon-on-insulator (SOI) waveguides. However, these technologies have problems such as large device size, difficulty in miniaturization, poor compatibility with CMOS processes, and high optical transmission losses. Summary of the Invention

[0004] In view of this, the present invention aims to provide a Brillouin semiconductor laser, which is at least beneficial to improving the integration and compactness of the Brillouin semiconductor laser while ensuring better performance of the Brillouin semiconductor laser.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] The present invention provides a Brillouin semiconductor laser, comprising: a gain chip having a first cavity surface and a second cavity surface disposed opposite to each other, the first cavity surface having a high-reflection film; a Bragg grating, the first end of the Bragg grating being connected to the second cavity surface; a microring resonator, the first end of the microring resonator being connected to the second end of the Bragg grating; a beam splitter located between the microring resonator and the Bragg grating; wherein, the gain chip is used to generate spontaneous emission light, the Bragg grating and the high-reflection film form a resonant cavity, the spontaneous emission light is processed by the resonant cavity to form pump light, the pump light is injected into the microring resonator through the second end of the Bragg grating, the microring resonator generates Stokes light by the stimulated Brillouin scattering effect, the microring resonator performs mode selection and amplification on the Stokes light, and ultra-narrow linewidth Brillouin laser is output from the first end of the microring resonator, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset ratio.

[0007] Further, the Brillouin semiconductor laser further comprises a mode spot converter, and the second cavity surface is connected to the Bragg grating through the mode spot converter.

[0008] Further, the waveguides corresponding to the Bragg grating, the waveguides corresponding to the mode spot converter, the waveguides corresponding to the beam splitter, and the waveguides corresponding to the microring resonator are all made of silicon nitride material.

[0009] Further, the waveguide corresponding to the Bragg grating includes a strip waveguide and a plurality of grating columns arranged at intervals, one end of the strip waveguide is connected to the second cavity surface, the other end of the strip waveguide is connected to the microring resonator, the plurality of grating columns are located on both sides of the strip waveguide, and the plurality of grating columns on each side of the strip waveguide are arranged at intervals along the extension direction of the strip waveguide.

[0010] Further, the linewidth of the pump light is in the range of 1 kHz to 100 kHz.

[0011] Further, the linewidth of the light beam output by the beam splitter according to a preset ratio is in the range of 1 Hz to 100 Hz.

[0012] Further, the Brillouin semiconductor laser further comprises a heat sink, and the gain chip is disposed on the heat sink.

[0013] Further, the second cavity surface has an antireflection film.

[0014] Further, along the direction from the gain chip to the microring resonator, the length of the Brillouin semiconductor laser is not greater than 1 cm.

[0015] Further, the Bragg grating is a low-reflection Bragg grating.

[0016] Compared with the prior art, the present invention can achieve the following beneficial effects: The Brillouin semiconductor laser provided by the present invention combines a Bragg grating, a microring resonator, and a gain chip, which is beneficial to reducing the volume of the Brillouin semiconductor laser and the manufacturing cost thereof. The Bragg grating and the gain chip are also coupled and integrated together through a spot size converter (SSC). The Bragg grating and the microring resonator can adopt Si3N4 waveguides. The Si3N4 material has low optical loss, high nonlinear coefficient, wide transparent window, and excellent optical field confinement ability, which is beneficial to achieving low-threshold lasing and ensuring a small device size. In addition, the Si3N4 material is compatible with the CMOS (Complementary Metal Oxide Semiconductor) process, suitable for large-scale integration, and has excellent thermal stability and mechanical strength, which is beneficial to realizing the integrated layout of the Brillouin semiconductor laser on a chip and improving the reliability of the Brillouin semiconductor laser. The Bragg grating is used as a filtering device to provide optical feedback of a specific mode for the gain chip to narrow the linewidth, and finally obtain a narrow-linewidth pump light for exciting the stimulated Brillouin scattering effect. The microring resonator is used to excite the stimulated Brillouin scattering effect to achieve the output of stable single-mode narrow-linewidth Brillouin laser. The sizes of the components of the Brillouin semiconductor laser provided by the present invention are small. Therefore, the layout of the Brillouin semiconductor laser is more compact, and it can be easily packaged into a package to form a modular and highly integrated Brillouin semiconductor laser. Moreover, the transmission loss of the Brillouin semiconductor laser is lower, and it is also easily compatible with the existing CMOS process, which not only solves the problems of large size, complex manufacturing, and low integration degree of the lasers in the prior art, but also improves the stability and performance of the laser system, and is beneficial to meeting the requirements of atomic detection for high-quality laser sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0018] Figure 1 is a top view of a Brillouin laser according to an embodiment provided by the present invention;

[0019] Figure 2 is a top view of a Brillouin laser according to another embodiment provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Analysis revealed that narrow-linewidth lasers based on fiber ring cavities typically require several kilometers of fiber to achieve sufficient Brillouin gain, making the entire system bulky and unsuitable for miniaturization and modular packaging. Furthermore, the long fiber ring cavity length results in a slow overall system response, making it unsuitable for applications requiring rapid modulation. For Brillouin semiconductor lasers based on As2S3 waveguides, the complex fabrication process and incompatibility with CMOS processes limit their large-scale production and application. Furthermore, the low mechanical strength of As2S3 material limits long-term reliability. Compared to As2S3 waveguides, SOI waveguides utilize a wider range of silicon-based materials, theoretically making them easier to integrate with existing CMOS technology. However, due to the inherently low photoelastic coefficient and high acoustic velocity of silicon, acoustic modes are poorly confined on the SOI platform, susceptible to increased optical loss and non-uniform broadening due to dimensional variations, thus limiting the achievable Brillouin amplification.

[0021] In order to solve the above problems, the present invention provides a Brillouin semiconductor laser with compact layout, easy integration and excellent performance.

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0025] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0026] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0027] Referring to Figure 1 , the Brillouin semiconductor laser provided by the present invention includes: a gain chip 3, the gain chip 3 has a first cavity surface and a second cavity surface arranged opposite to each other, and the first cavity surface has a high-reflection film; a Bragg grating 2, the first end of the Bragg grating 2 is connected to the second cavity surface; a microring resonator 1, the first end of the microring resonator 1 is connected to the second end of the Bragg grating 2; a beam splitter 6, the beam splitter 6 is located between the microring resonator 1 and the Bragg grating 2; wherein, the gain chip 3 is used to generate spontaneous emission light, the Bragg grating 2 and the high-reflection film form a resonant cavity, the spontaneous emission light is processed by the resonant cavity to form pump light, the pump light is injected into the microring resonator 1 through the second end of the Bragg grating 2, the microring resonator 1 generates Stokes light through the stimulated Brillouin scattering effect, the microring resonator 1 performs mode selection and amplification on the Stokes light, and ultra-narrow linewidth Brillouin laser is output from the first end of the microring resonator 1, and the beam splitter 6 outputs the ultra-narrow linewidth Brillouin laser according to a preset ratio.

[0028] In some embodiments, the preset ratio is not less than 90%. It should be noted that on the premise of being achievable, the higher the preset ratio, the better.

[0029] In some embodiments, the Bragg grating 2 is a low-reflection Bragg grating. The reflectivity of the low-reflection Bragg grating is in the range of 10% to 30%.

[0030] In some embodiments, the reflectivity of the high-reflection film is greater than 99%. It should be noted that on the premise of being achievable, the higher the reflectivity of the high-reflection film, the better.

[0031] It should be noted that the Bragg grating 2 in the present invention has the feedback function of specific-mode light, and the microring resonator 1 supports the stimulated Brillouin scattering effect. The Brillouin semiconductor laser provided by the present invention utilizes the narrowband filtering characteristic of the Bragg grating 2 to obtain a pump light with a narrow linewidth of a specific wavelength, and generates an ultra-narrow linewidth Brillouin laser output through the stimulated Brillouin scattering effect of the microring resonator 1. Compared with the conventional fiber-structure-based Brillouin laser, the present invention significantly simplifies the structure of the Brillouin semiconductor laser, which is beneficial to reducing the volume of the Brillouin semiconductor laser.

[0032] The gain chip 3 needs to adopt a quantum well structure. The gain chip 3 has the output characteristic of a wide amplified spontaneous emission (ASE) spectrum and is used as an active gain medium. A high-reflection film is deposited on the first cavity surface of the gain chip 3. The high-reflection film and the Bragg grating 2 together form a resonant cavity to achieve the efficient lasing of the pump light. The gain chip 3 serves as the core light source of the entire laser. The gain chip 3 can include high-performance semiconductor gain materials to achieve coverage of a wide wavelength range and support high-power output. Moreover, the broadband light source characteristic of the gain chip 3 lays the foundation for subsequent wavelength selection and nonlinear processing. The compactness and high efficiency of the gain chip 3 enable the formed Brillouin semiconductor laser to have the characteristics of miniaturization and low power consumption.

[0033] In some embodiments, the waveguide of the gain chip 3 can be a straight waveguide or a bent waveguide with a certain angle.

[0034] In some embodiments, the Brillouin semiconductor laser further includes a mode spot converter 5. The second cavity surface is connected to the Bragg grating 2 through the mode spot converter 5. The mode spot converter 5 is used to achieve the efficient coupling between the gain chip 3 and the Bragg grating 2. In some examples, the mode spot converter 5 can adopt a common tapered waveguide mode spot converter 5. The main function of the mode spot converter 5 is to efficiently convert the mode field size or shape between different waveguides to achieve low-loss coupling and transmission of light. By precisely matching the mode field distributions between the gain chip 3 and the Bragg grating 2, the beam quality can be significantly improved, the system loss can be reduced, and thus the output power, stability, and application performance of the Brillouin semiconductor laser can be enhanced.

[0035] For a Brillouin semiconductor laser including a mode spot converter 5, a gain chip 3 generates broadband spontaneous emission light, which is coupled to a Bragg grating 2 through the mode spot converter 5. The Bragg grating 2 extracts single-mode narrow-linewidth pump light through wavelength-selective feedback and feeds it back into the microring resonator 1. The narrow-linewidth pump light is injected into the microring resonator 1 to generate the SBS effect, enabling the interaction between light waves and acoustic waves to generate Stokes light with a frequency shift. Moreover, the microring resonator 1 performs mode selection and amplification on the Stokes light, and outputs ultra-narrow-linewidth Brillouin laser. The beam splitter 6 outputs the ultra-narrow-linewidth Brillouin laser proportionally, while suppressing the interference of the backward-propagating Brillouin laser on the pump light.

[0036] In some embodiments, the waveguides corresponding to the Bragg grating 2, the waveguides corresponding to the mode spot converter 5, the waveguides corresponding to the beam splitter 6, and the waveguides corresponding to the microring resonator 1 are all made of silicon nitride material.

[0037] Using silicon nitride to form the Bragg grating 2, the microring resonator 1, the mode spot converter 5, and the beam splitter 6 is not only beneficial to compatibility with existing CMOS processes, but also enables a compact layout in terms of device size. Furthermore, the Brillouin semiconductor laser can be packaged in a butterfly package, thereby obtaining a highly compact and highly integrated modular laser.

[0038] In some embodiments, the Bragg grating 2, the microring resonator 1, the beam splitter 6, and the mode spot converter 5 are all disposed on a silicon-based substrate. A first silicon dioxide thin film is grown on the silicon-based substrate, and the first silicon dioxide thin film is used as the lower cladding of the waveguide. On the first silicon dioxide thin film, there are disposed the waveguides corresponding to the Bragg grating 2, the waveguides corresponding to the beam splitter 6, the waveguides corresponding to the microring resonator 1, and the waveguides corresponding to the mode spot converter 5. The waveguides are used as optical transmission channels, and a second silicon dioxide thin film is disposed on the waveguides corresponding to the Bragg grating 2, the waveguides corresponding to the beam splitter 6, the waveguides corresponding to the microring resonator 1, and the waveguides corresponding to the mode spot converter 5. The second silicon dioxide thin film is used as the upper cladding of the waveguide. In this way, the Bragg grating 2, the beam splitter 6, the microring resonator 1, and the mode spot converter 5 can be prepared by using existing CMOS processes, which not only realizes the small-volume integration of the Brillouin semiconductor laser, but also reduces the preparation difficulty and cost.

[0039] In some embodiments, the waveguide corresponding to the Bragg grating 2 includes a strip waveguide and a plurality of grating posts arranged at intervals. One end of the strip waveguide is connected to the second cavity surface, and the other end of the strip waveguide is connected to the microring resonator 1. The plurality of grating posts are located on both sides of the strip waveguide, and the plurality of grating posts on each side of the strip waveguide are arranged at intervals along the extension direction of the strip waveguide. The filtering bandwidth and coupling strength of the Bragg grating 2 can be adjusted by changing the distance between the grating posts and the strip waveguide. The Bragg grating 2 with this structure has the characteristics of a small coupling coefficient and easy adjustment of the coupling coefficient.

[0040] The Bragg grating 2 is the core wavelength selection device in the Brillouin semiconductor laser. Through its high-precision periodic refractive index modulation structure, the Bragg grating 2 can efficiently reflect light of a specific wavelength. The light of the specific wavelength is the light that satisfies the Bragg resonance condition, and the light of other wavelengths does not satisfy the Bragg resonance condition. The light that satisfies the Bragg resonance condition needs to be fed back to the gain chip 3. The specific wavelength is the wavelength for forming the pump light. The characteristic that the Bragg grating 2 efficiently reflects light of a specific wavelength not only ensures the stability of the output wavelength of the Brillouin semiconductor laser but also effectively suppresses the side mode output, thereby realizing narrow linewidth single-mode laser output. The periodic refractive index modulation structure of the Bragg grating 2 has a periodic dielectric perturbation in the propagation direction of the optical mode. Therefore, the Bragg grating 2 can be used as a filtering device to provide optical feedback of a specific mode to narrow the linewidth, and finally obtain a narrow linewidth pump light to excite the SBS effect.

[0041] The Bragg grating 2 is used to perform narrowband filtering on the broadband spontaneous emission light output by the gain chip 3, extract the target pump wavelength therefrom, and at the same time suppress the multimode oscillation behavior of the gain chip 3 through its wavelength selective feedback mechanism. This narrowband filtering mechanism can not only narrow the laser linewidth but also improve the wavelength stability and spectral purity of the Brillouin semiconductor laser, as well as ensure that the pump light can meet the high-quality requirements of subsequent stimulated Brillouin scattering. In the present invention, a Bragg grating 2 with a low reflectivity is used as the equivalent resonator surface to ensure that the pump light can be injected into the microring resonator 1.

[0042] Silicon nitride (Si3N4) has low loss and high thermal stability. The Bragg grating 2 made of silicon nitride material can provide high-quality optical feedback and precise wavelength selection, which is beneficial to significantly compress the linewidth of the pump light and improve the spectral purity of the pump light. At the same time, it is beneficial to enhance the stability and anti-noise ability of the Brillouin semiconductor laser.

[0043] In some embodiments, the linewidth of the pump light is in the range of 1 kHz to 100 kHz.

[0044] The microring resonator 1 is a component for realizing the stimulated Brillouin scattering effect. The microring resonator 1 utilizes its ring waveguide structure to form a resonant mode with a high quality factor, enabling light to propagate multiple times in the ring waveguide structure, greatly enhancing the light field intensity and the interaction efficiency between light and the medium. When a high-intensity pump light passes through the microring resonator 1, it interacts with the acoustic wave in the ring waveguide structure to generate Stokes light with a frequency shift. That is to say, as a nonlinear optical element of the Brillouin semiconductor laser, the high quality factor and low optical loss characteristics of the microring resonator 1 can confine the light field in the ring waveguide structure, significantly enhancing the interaction between the pump light and phonons, thereby promoting the stimulated Brillouin scattering effect. The Brillouin gain generated by this strong interaction between light and phonons can effectively amplify the Stokes light of a specific frequency, ultimately achieving a narrow linewidth and low-noise laser output.

[0045] Due to the characteristics of high quality factor, small mode volume, and low optical loss of the silicon nitride material, the microring resonator 1 made of silicon nitride material can greatly enhance the Brillouin gain, while reducing the threshold of Brillouin lasing, achieving high-efficiency Brillouin laser output, enabling the Brillouin semiconductor laser to maintain stable output performance under extreme conditions. The natural linewidth compression mechanism of the stimulated Brillouin scattering effect narrows the laser linewidth to the kHz or even Hz level, which is particularly important for high-precision applications such as atomic detection.

[0046] Since the stimulated Brillouin scattering effect generates Stokes light propagating in the opposite direction to the pump light, to avoid the influence of the backward-propagating Stokes light on the pump light to the greatest extent, by introducing a beam splitter 6 with a high splitting ratio (the splitting ratio is greater than 99:1), the forward and backward-propagating optical signals can be effectively isolated, reducing the influence of the backward-propagating Stokes light on the pump light, avoiding unnecessary interference, and ensuring the purity and stability of the output Brillouin laser.

[0047] In some embodiments, the linewidth of the light beam output by the beam splitter 6 according to a preset ratio is in the range of 1 Hz to 100 Hz. The light beam output by the beam splitter 6 according to a preset ratio is an ultra-narrow linewidth Brillouin laser.

[0048] In some embodiments, the Brillouin semiconductor laser further includes a heat sink 4, and the gain chip 3 is disposed on the heat sink 4. The heat sink 4 is used to quickly conduct the heat generated during the operation of the gain chip 3, thereby protecting the device, maintaining its normal operating temperature, and extending its service life.

[0049] In some embodiments, the second cavity surface has an antireflection film. The antireflection film is used to reduce the coupling loss between the gain chip 3 and the Bragg grating 2, and can effectively suppress the Fabry - Pérot (F - P) effect caused by the reflection of the second cavity surface, thereby ensuring the high-quality output of the pump light. In some examples, refer toFigure 2 The Fabry-Perot effect of the gain chip 3 itself can be further suppressed by designing a gain chip 3 with a curved waveguide. It should be noted that the extension direction of the curved waveguide forms a certain angle with the light output direction, which can reduce the dependence on the quality of the anti-reflection film.

[0050] In some embodiments, the length of the Brillouin semiconductor laser along the direction from the gain chip 3 to the microring resonator 1 is no longer than 1 cm.

[0051] The Brillouin semiconductor laser proposed in the present invention has high compactness and integration. Specifically, the Bragg grating 2, the microring resonator 1, the beam splitter 6 and the gain chip 3 are combined to form the Brillouin semiconductor laser, which not only allows the total length of the Brillouin semiconductor laser to be controlled within the centimeter scale, but also facilitates modular packaging with a compact design, and provides the possibility of integration into more complex systems. In addition, the use of Si3N4 material not only improves the performance of the Brillouin semiconductor laser, but also reduces the manufacturing cost and process complexity of the Brillouin semiconductor laser. Specifically, Si3N4 is compatible with CMOS technology, which means that existing semiconductor production lines can be used for large-scale production, which is conducive to reducing costs. This compatibility provides broad space for future integrated development, allowing the Brillouin semiconductor laser to be seamlessly integrated with other electronic components to form a multifunctional optoelectronic system. Compared with traditional Brillouin semiconductor lasers composed of fiber ring cavities or specific waveguide structures, the present invention does not require complex long-distance optical fibers or special preparation processes, making the manufacturing process of Brillouin semiconductor lasers simpler and more economical; the Brillouin semiconductor laser provided by the present invention is particularly suitable for the field of atomic detection. During the atomic detection process, there are extremely strict requirements on the line width, coherence and noise level of the laser light source. The Brillouin semiconductor laser provided by the present invention, with its ultra-narrow line width, high coherence and low noise characteristics, can significantly improve the accuracy and efficiency of atomic detection, meeting the needs of high-end scientific research and industrial applications.

[0052] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0053] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A Brillouin semiconductor laser, characterized in that, Comprising: A gain chip having a first cavity surface and a second cavity surface disposed opposite to each other, the first cavity surface having a high reflection film; A Bragg grating, a first end of the Bragg grating being connected to the second cavity surface; A micro-ring resonator, a first end of the micro-ring resonator being connected to a second end of the Bragg grating; A beam splitter located between the micro-ring resonator and the Bragg grating; Wherein, the gain chip is used to generate spontaneous emission light, the Bragg grating and the high reflection film form a resonant cavity, the spontaneous emission light is processed by the resonant cavity to form pump light, the pump light is injected into the micro-ring resonator through the second end of the Bragg grating, the micro-ring resonator generates Stokes light by stimulated Brillouin scattering effect, the micro-ring resonator performs mode selection and amplification on the Stokes light, and ultra-narrow linewidth Brillouin laser is output from the first end of the micro-ring resonator, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset ratio.

2. The Brillouin semiconductor laser according to claim 1, wherein The Brillouin semiconductor laser further includes a mode spot converter, and the second cavity surface is connected to the Bragg grating through the mode spot converter.

3. The Brillouin semiconductor laser according to claim 2, characterized in that, The waveguides corresponding to the Bragg grating, the waveguides corresponding to the mode spot converter, the waveguides corresponding to the beam splitter, and the waveguides corresponding to the micro-ring resonator are all made of silicon nitride material.

4. The Brillouin semiconductor laser according to claim 3, characterized in that, The waveguide corresponding to the Bragg grating includes a strip waveguide and a plurality of grating columns arranged at intervals, one end of the strip waveguide is connected to the second cavity surface, the other end of the strip waveguide is connected to the micro-ring resonator, and the plurality of grating columns are located on both sides of the strip waveguide and are arranged at intervals along the extension direction of the strip waveguide on each side of the strip waveguide.

5. The Brillouin semiconductor laser according to claim 1, characterized in that, The linewidth of the pump light is in the range of 1 kHz to 100 kHz.

6. The Brillouin semiconductor laser according to claim 5, characterized in that, The linewidth of the light beam output by the beam splitter according to a preset ratio is in the range of 1 Hz to 100 Hz.

7. The Brillouin semiconductor laser according to claim 1, characterized in that, The Brillouin semiconductor laser further includes a heat sink, and the gain chip is disposed on the heat sink.

8. The Brillouin semiconductor laser according to claim 1, characterized in that, The second cavity surface has an anti-reflection film.

9. The Brillouin semiconductor laser according to claim 1, wherein Along the direction from the gain chip to the micro-ring resonator, the length of the Brillouin semiconductor laser is not greater than 1 cm.

10. The Brillouin semiconductor laser according to claim 1, characterized in that, The Bragg grating is a low reflection Bragg grating.

Images