A brillouin hybrid integrated laser

Abstract

The application relates to the technical field of lasers, in particular to a Brillouin hybrid integrated laser, which comprises a gain chip, a Bragg grating connected with a first cavity surface, a micro-ring resonator with a first end connected with a second cavity surface, and a beam splitter located between the micro-ring resonator and the gain chip. The gain chip is used for generating spontaneous emission light, the Bragg grating and a low-reflection film form a resonant cavity, the spontaneous emission light forms pump light after being processed by the resonant cavity, the pump light is injected into the micro-ring resonator through the second cavity surface, the micro-ring resonator generates stimulated Brillouin scattering effect to generate Stokes light, the micro-ring resonator selects and amplifies the Stokes light to output super-narrow-line-width Brillouin laser, and the beam splitter outputs the super-narrow-line-width Brillouin laser according to a preset ratio. The application is at least beneficial to improving the integration and compactness of the Brillouin hybrid integrated laser while ensuring that the Brillouin hybrid integrated laser has better performance.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and particularly relates to a Brillouin hybrid integrated laser. Background Technology

[0002] Semiconductor lasers play a crucial role in atomic detection, particularly in high-precision spectral analysis and quantum manipulation. These applications require laser sources with ultra-narrow linewidths, high coherence, and low noise characteristics to ensure precise atomic state manipulation and detection efficiency. In the generation of ultra-narrow linewidth lasers, stimulated Brillouin scattering (SBS) has proven to be an effective method for achieving high-purity spectral output. Stimulated Brillouin scattering is an important nonlinear optical phenomenon, referring to the light scattering phenomenon generated by the interaction between light waves incident on an optical medium and elastic acoustic waves within the medium. Due to the statistical thermal motion of numerous particles within the optical medium, elastic acoustic waves are generated, causing periodic changes in the density of the optical medium with time and space. This, in turn, causes periodic changes in the refractive index of the optical medium with time and space. Therefore, the acoustic vibration medium can be considered as a moving grating. Thus, when a beam of light with frequency ω passes through the optical medium, it will generate light waves with frequency ω within the optical medium. s Coherent sound waves, simultaneously generating frequencies of (ω-ω s The scattered light waves, i.e., Stokes light, are emitted by the sound waves. Both the sound waves and Stokes light propagate in specific directions, and the aforementioned phenomenon only occurs when the incident light intensity exceeds a certain value. This type of Brillouin scattering, exhibiting stimulated emission characteristics, is called stimulated Brillouin scattering. For stimulated Brillouin scattering, the phase noise of the pump light is greatly suppressed by the combined effect of cavity feedback and phonon oscillation. Only a small portion is transferred to the phase of the Stokes light, thus greatly suppressing the linewidth of the output Brillouin laser.

[0003] Traditionally, Brillouin semiconductor lasers primarily generate Brillouin laser light through stimulated Brillouin scattering, based on erbium-doped fiber amplifiers (EDFAs) and specific waveguide structures. These specific waveguide structures can be chalcogenide glass waveguides (e.g., As2S3 waveguides) or silicon-on-insulator (SOI) waveguides. However, these technologies suffer from drawbacks such as large device size, difficulty in miniaturization, poor compatibility with CMOS processes, and high optical transmission loss. Summary of the Invention

[0004] In view of this, the present invention aims to provide a Brillouin hybrid integrated laser, which at least helps to improve the integration and compactness of the Brillouin hybrid integrated laser while ensuring its superior performance.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0006] This invention provides a Brillouin hybrid integrated laser, comprising: a gain chip having a first cavity surface and a second cavity surface disposed opposite to each other, the second cavity surface having a low-reflection film; a Bragg grating connected to the first cavity surface; a microring resonator, the first end of which is connected to the second cavity surface; and a beam splitter located between the microring resonator and the gain chip. The gain chip generates spontaneous emission light, the Bragg grating and the low-reflection film constitute 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 cavity surface, the microring resonator undergoes stimulated Brillouin scattering to generate Stokes light, the microring resonator performs mode-selective amplification of the Stokes light, and outputs an ultra-narrow linewidth Brillouin laser from the output end of the microring resonator, the beam splitter outputs the ultra-narrow linewidth Brillouin laser at a preset ratio.

[0007] Furthermore, the Brillouin hybrid integrated laser also includes a first mode converter and a second mode converter. The first cavity surface is connected to the Bragg grating through the first mode converter, and the second cavity surface is connected to the first end of the microring resonator through the second mode converter. The beam splitter is located between the second mode converter and the microring resonator.

[0008] Furthermore, the material of the Bragg grating is silicon nitride.

[0009] Furthermore, the Bragg grating includes a spaced-apart strip waveguide and a plurality of grating pillars. One end of the strip waveguide is connected to the first cavity surface, and the plurality of grating pillars are located on both sides of the strip waveguide. The plurality of grating pillars on each side of the strip waveguide are spaced apart along the extension direction of the strip waveguide.

[0010] Furthermore, the material of the microring resonator is silicon nitride.

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

[0012] Furthermore, the Brillouin hybrid integrated laser also includes a heat sink, on which the gain chip is mounted.

[0013] Furthermore, the first cavity surface has an anti-reflective membrane.

[0014] Furthermore, along the direction from the Bragg grating to the microring resonator, the length of the Brillouin hybrid integrated laser is no greater than 1 cm.

[0015] Furthermore, the Bragg grating is a high-reflectivity Bragg grating.

[0016] Compared with existing technologies, the present invention achieves the following beneficial effects: The Brillouin hybrid integrated laser provided by the present invention combines a Bragg grating, a microring resonator, and a gain chip, and integrates them together through a spot size converter (SSC). This helps to reduce the size and fabrication cost of the Brillouin hybrid integrated laser. Specifically, the Bragg grating and the microring resonator can be Si3N4 waveguides. Si3N4 material has low optical loss, high nonlinear coefficient, wide transparency window, and excellent optical field confinement capability, which is beneficial for achieving low threshold lasing and ensuring a small device size. In addition, Si3N4 material is compatible with CMOS (Complementary Metal Oxide Semiconductor) processes, suitable for large-scale integration, and has excellent thermal stability and mechanical strength, which is beneficial for on-chip integration of the Brillouin hybrid integrated laser and for improving the reliability of the Brillouin hybrid integrated laser. A Bragg grating, used as a filter device, provides specific mode optical feedback to the gain chip to narrow the linewidth, ultimately resulting in narrow-linewidth pump light for exciting stimulated Brillouin scattering (SBS). A microring resonator is used to excite SBS to achieve a stable single-mode narrow-linewidth Brillouin laser output. The components of the Brillouin hybrid integrated laser provided by this invention are relatively small, resulting in a more compact layout. It can be easily packaged into a single package to form a modular, highly integrated Brillouin hybrid integrated laser. Furthermore, the Brillouin hybrid integrated laser exhibits lower transmission loss and is easily compatible with existing CMOS processes. This not only solves the problems of excessively large laser size, complex fabrication, and low integration in existing technologies but also improves the stability and performance of the laser system, thus meeting the demand for high-quality laser sources in atomic detection. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A top view of a Brillouin hybrid integrated laser according to an embodiment of the present invention;

[0019] Figure 2 A top view of a Brillouin hybrid integrated laser according to another embodiment provided for the present invention. Detailed Implementation

[0020] Analysis revealed that for narrow-linewidth lasers based on fiber ring cavities, the need for several kilometers of fiber to achieve sufficient Brillouin gain results in a bulky system, hindering miniaturization and modular packaging. Furthermore, the long length of the fiber ring cavity leads to a slow overall system response, making it unsuitable for applications requiring rapid modulation. For Brillouin hybrid integrated lasers based on As2S3 waveguides, the complex fabrication process of As2S3 waveguides and their incompatibility with CMOS processes limit large-scale production and application. Additionally, the low mechanical strength of As2S3 material leads to poor long-term reliability. For Brillouin hybrid integrated lasers based on SOI waveguides, SOI waveguides utilize a wider range of silicon-based materials, theoretically making integration with existing CMOS technologies easier. However, the low photoelasticity and high acoustic velocity of silicon result in poor acoustic mode confinement on the SOI platform, leading to increased optical loss and non-uniform broadening effects caused by size variations, thus limiting the achievable Brillouin amplification effect.

[0021] To address the aforementioned problems, this invention provides a Brillouin hybrid integrated laser that is compact, easy to integrate, and has superior performance.

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be 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 merely illustrative of the invention and do not constitute a limitation thereof.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] refer to Figure 1 The Brillouin hybrid integrated laser provided by this invention includes: a gain chip 3, which has a first cavity surface and a second cavity surface disposed opposite to each other, the second cavity surface having a low-reflection film; a Bragg grating 2, which is connected to the first cavity surface; a micro-ring resonator 1, the first end of which is connected to the second cavity surface; and a beam splitter 7, which is located between the micro-ring resonator 1 and the gain chip 3. The gain chip 3 is used to generate spontaneous emission light. The Bragg grating 2 and the low-reflection film constitute 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 1 through the second cavity surface. The micro-ring resonator 1 undergoes stimulated Brillouin scattering to generate Stokes light. The micro-ring resonator 1 performs mode-selective amplification of the Stokes light and outputs an ultra-narrow linewidth Brillouin laser from the first end of the micro-ring resonator 1. The beam splitter 7 outputs the ultra-narrow linewidth Brillouin laser at a preset ratio.

[0028] In some embodiments, the preset ratio is not less than 90%. It should be noted that, provided it is feasible, the higher the preset ratio, the better.

[0029] In some embodiments, the Bragg grating is a high-reflectivity Bragg grating. The reflectivity of the high-reflectivity Bragg grating is greater than 99%. It should be noted that, where feasible, the higher the reflectivity of the high-reflectivity Bragg grating, the better.

[0030] It should be noted that the Bragg grating 2 in this invention has a feedback function for specific mode light, and the microring resonator 1 supports stimulated Brillouin scattering effect.

[0031] In some embodiments, the material of the Bragg grating 2 is silicon nitride.

[0032] In some embodiments, the Bragg grating 2 includes a spaced-apart strip waveguide and a plurality of grating pillars. One end of the strip waveguide is connected to a first cavity surface, and the plurality of grating pillars are located on both sides of the strip waveguide, with the grating pillars on each side of the strip waveguide 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 pillars and the strip waveguide. This structure of the Bragg grating 2 has the characteristics of a small coupling coefficient and easy adjustment of the coupling coefficient.

[0033] In some embodiments, the material of the microring resonator 1 is silicon nitride.

[0034] The Brillouin hybrid integrated laser provided by this invention utilizes the narrow-band filtering characteristics of the Bragg grating 2 to obtain pump light with a narrow linewidth at 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 traditional Brillouin hybrid integrated lasers based on fiber structures, this invention significantly simplifies the structure of the Brillouin hybrid integrated laser, which is beneficial for reducing its size. Using silicon nitride to form the Bragg grating 2 and the microring resonator 1 facilitates compatibility with existing CMOS processes, enabling a compact layout in terms of device size. This allows the Brillouin hybrid integrated laser to be packaged in a butterfly-shaped package, thereby obtaining a modular laser with high compactness and high integration.

[0035] It should be noted that the gain chip 3 needs to adopt a quantum well structure. Gain chip 3 possesses a wide amplified spontaneous emission (ASE) spectrum output characteristic, serving as the active gain medium. The second cavity surface of gain chip 3 is coated with a low-reflection film. In some examples, the reflectivity of the low-reflection film is in the range of 10% to 30%. The low-reflection film, together with the Bragg grating 2, constitutes a resonant cavity, achieving efficient lasing of the pump light. As the core light source of the entire laser, gain chip 3 can include high-performance semiconductor gain materials to achieve coverage of a wide wavelength range and support high-power output. Furthermore, the broadband light source characteristics of gain chip 3 lay the foundation for subsequent wavelength selection and nonlinear processing. The compactness and high efficiency of gain chip 3 enable the Brillouin hybrid integrated laser formed by it to possess miniaturization and low power consumption characteristics.

[0036] In some embodiments, the waveguide of the gain chip 3 can be a straight waveguide or a curved waveguide with a certain angle.

[0037] Bragg grating 2 is the core wavelength selection device in Brillouin hybrid integrated lasers. Through its high-precision periodic refractive index modulation structure, 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, while other wavelengths do not. The light that satisfies the Bragg resonance condition needs to be fed back to the gain chip. The specific wavelength is the wavelength that forms the pump light. The characteristic of Bragg grating 2 to efficiently reflect light of a specific wavelength not only ensures the stability of the output wavelength of the Brillouin hybrid integrated laser, but also effectively suppresses side-mode output, thereby realizing narrow linewidth single-mode laser output. The periodic refractive index modulation structure of Bragg grating 2 has periodic dielectric perturbations in the propagation direction of the optical mode. Therefore, Bragg grating 2 can be used as a filter device to provide optical feedback of a specific mode to narrow the linewidth, and finally obtain narrow linewidth pump light to excite the SBS effect.

[0038] In some embodiments, the linewidth of the pump light is in the range of 1 kHz to 100 kHz.

[0039] The Bragg grating 2 is connected to the first cavity surface of the gain chip 3, which optimizes the optical feedback path and reduces unnecessary reflection losses. The Bragg grating 2 is used for narrowband filtering of the broadband spontaneous emission light output from the gain chip 3, extracting the target pump wavelength. Simultaneously, its wavelength-selective feedback mechanism suppresses the multimode oscillation behavior of the gain chip 3. This narrowband filtering mechanism not only narrows the laser linewidth but also improves the wavelength stability and spectral purity of the Brillouin hybrid integrated laser, ensuring that the pump light meets the high-quality requirements of subsequent stimulated Brillouin scattering. Furthermore, the high-reflectivity Bragg grating 2 is used as the equivalent resonant cavity surface in this invention to ensure that most of the light waves can return to the gain chip 3 for resonance.

[0040] Silicon nitride (Si3N4) has low loss and high thermal stability. Bragg gratings made of silicon nitride can provide high-quality optical feedback and precise wavelength selection, which is beneficial for significantly compressing the linewidth of the pump light and improving the spectral purity of the pump light. At the same time, it is beneficial for enhancing the stability and noise immunity of Brillouin hybrid integrated lasers.

[0041] Microring resonator 1 is the component that realizes the stimulated Brillouin scattering effect. Microring resonator 1 utilizes its ring waveguide structure to form a high-quality-factor resonant mode, allowing light to circulate multiple times within the ring waveguide structure, greatly improving the optical field intensity and the efficiency of light-medium interaction. When high-intensity pump light passes through microring resonator 1, it interacts with acoustic waves within the ring waveguide structure, generating Stokes light with a lower frequency. In other words, as a nonlinear optical element of the Brillouin hybrid integrated laser, microring resonator 1's high-quality-factor and low-loss characteristics confine the optical field within the ring waveguide structure, significantly enhancing the interaction between pump light and phonons, thereby promoting the stimulated Brillouin scattering effect. This Brillouin gain generated by the interaction of strong light and phonons can effectively amplify Stokes light at a specific frequency, ultimately achieving narrow-linewidth, low-noise laser output.

[0042] Due to the high quality factor, small mode volume, and low optical loss characteristics of silicon nitride (SiN), a microring resonator using SiN can significantly enhance Brillouin gain while lowering the Brillouin lasing threshold, achieving high-efficiency Brillouin laser output. This allows the Brillouin hybrid integrated laser to maintain stable output performance even under extreme conditions. The natural linewidth compression mechanism of stimulated Brillouin scattering narrows the laser linewidth to the kHz or even Hz level, which is particularly important for high-precision applications such as atomic detection.

[0043] Since stimulated Brillouin scattering produces Stokes light that propagates in the opposite direction to the pump light, in order to minimize the impact of the reverse-propagating Stokes light on the gain chip 3, a beam splitter 7 with a high splitting ratio (greater than 99:1) is introduced. This effectively isolates the forward and reverse propagating optical signals, reduces the impact of the reverse-propagating Stokes light on the pump light, avoids unnecessary interference, and ensures the purity and stability of the output Brillouin laser.

[0044] In some embodiments, the Brillouin hybrid integrated laser further includes a first mode converter 5 and a second mode converter 6. A first cavity surface is connected to a Bragg grating 2 via the first mode converter 5, and a second cavity surface is connected to a first end of a microring resonator 1 via the second mode converter 6. A beam splitter 7 is located between the second mode converter 6 and the microring resonator 1. The first mode converter 5 and the second mode converter 6 are used to achieve mode matching and efficient coupling between the gain chip 3 and the various components. In some examples, both the first mode converter 5 and the second mode converter 6 can be common inverted conical waveguide mode converters.

[0045] The main function of the first mode converter 5 and the second mode converter 6 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 distribution between the gain chip 3 and the Bragg grating 2, and by precisely matching the mode field distribution between the gain chip 3 and the ring resonator, the beam quality can be significantly improved, the system loss can be reduced, and the output power, stability and application performance of the Brillouin hybrid integrated laser can be improved.

[0046] For a Brillouin hybrid integrated laser including a first mode-spot converter 5 and a second mode-spot converter 6, the gain chip 3 generates broadband spontaneous emission light, which is coupled to the Bragg grating 2 via the first mode-spot converter 5. The Bragg grating 2 extracts single-mode narrow-linewidth pump light through wavelength selective feedback and feeds it back to the micro-ring resonator 1. The narrow-linewidth pump light is injected into the micro-ring resonator 1, generating the SBS effect, which causes the light wave to interact with the sound wave and generate Stokes light with a lower frequency. The micro-ring resonator 1 performs mode-selective amplification of the Stokes light and outputs an ultra-narrow-linewidth Brillouin laser. The beam splitter 7 outputs the ultra-narrow-linewidth Brillouin laser proportionally while suppressing the interference of the back-propagating Brillouin laser on the pump light.

[0047] In some embodiments, the linewidth of the beam output by the beam splitter 7 according to a preset ratio is in the range of 1Hz to 100Hz, and the beam output by the beam splitter 7 according to the preset ratio is an ultra-narrow linewidth laser.

[0048] In some embodiments, the Brillouin hybrid integrated laser also includes a heat sink 4, on which the gain chip 3 is disposed. The heat sink 4 is used to rapidly dissipate the heat generated by the gain chip 3 during operation, thereby protecting the device, maintaining its normal operating temperature, and extending its service life.

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

[0050] In some embodiments, the length of the Brillouin hybrid integrated laser is no more than 1 cm along the direction from the Bragg grating 2 to the microring resonator 1.

[0051] In some embodiments, the materials of the Bragg grating 2, beam splitter 7, microring resonator 1, first mode converter 5, and second mode converter 6 all include Si3N4, and the Bragg grating 2, microring resonator 1, beam splitter 7, first mode converter 5, and second mode converter 6 are all disposed on a silicon substrate. A first silicon dioxide thin film is grown on the silicon substrate, and the first silicon dioxide thin film is used as the lower cladding of the waveguide. Multiple waveguides for forming the Bragg grating 2, beam splitter 7, microring resonator 1, first mode converter 5, and second mode converter 6 are disposed on the first silicon dioxide thin film. The waveguide corresponding to each component of the Bragg grating 2, beam splitter 7, microring resonator 1, first mode converter 5, and second mode converter 6 can all be made of Si3N4 material. The waveguide is used as an optical transmission channel, and a second silicon dioxide thin film is disposed on the waveguide corresponding to each component of the Bragg grating 2, beam splitter 7, microring resonator 1, first mode converter 5, and second mode converter 6. The second silicon dioxide thin film is used as the upper cladding of the waveguide. Thus, the Bragg grating 2, beam splitter 7, micro-ring resonator 1, first mode spot converter 5, and second mode spot converter 6 can be fabricated using existing CMOS processes. This not only achieves small-volume integration of the Brillouin hybrid integrated laser, but also reduces the fabrication difficulty and cost.

[0052] The Brillouin hybrid integrated laser proposed in this invention has high compactness and integration. Specifically, by placing the Bragg grating 2 on the first cavity surface of the gain chip 3 and depositing a low-reflection film on the second cavity surface of the gain chip 3, a more compact layout is achieved. The Bragg grating 2, micro-ring resonator 1, beam splitter 7, first mode converter 5, and second mode converter 6 can all be made of Si3N4 material, which allows the total length of the Brillouin hybrid integrated laser to be controlled on the centimeter scale. The compact design not only facilitates modular packaging but also provides the possibility of integration into more complex systems. In addition, the use of Si3N4 material not only improves the performance of the Brillouin hybrid integrated laser but also reduces its manufacturing cost and process complexity. Specifically, Si3N4 is compatible with CMOS processes, which means that it can be mass-produced using existing semiconductor production lines, thereby helping to reduce costs. Moreover, this compatibility provides broad space for future integration development, enabling the Brillouin hybrid integrated laser to be seamlessly integrated with other electronic components to form a multifunctional optoelectronic system. Compared to traditional Brillouin hybrid integrated lasers constructed from fiber ring cavities or specific waveguide structures, this invention eliminates the need for complex long-distance optical fibers or special fabrication processes, making the manufacturing process of Brillouin hybrid integrated lasers simpler and more economical. The Brillouin hybrid integrated laser provided by this invention is particularly suitable for the field of atomic detection. In atomic detection, there are extremely stringent requirements for the linewidth, coherence, and noise level of the laser source. The Brillouin hybrid integrated laser provided by this invention, with its ultra-narrow linewidth, 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.

[0053] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0054] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A Brillouin hybrid integrated laser, characterized in that, include: A gain chip having a first cavity surface and a second cavity surface disposed opposite to each other, the second cavity surface having a low-reflection film; A Bragg grating, wherein the Bragg grating is connected to the first cavity surface; A microring resonator, wherein a first end of the microring resonator is connected to the second cavity surface; A beam splitter is located between the microring resonator and the gain chip; The gain chip is used to generate spontaneous emission light. The Bragg grating and the low-reflection film constitute 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 cavity surface. The microring resonator undergoes stimulated Brillouin scattering to generate Stokes light. The microring resonator performs mode-selective amplification of the Stokes light and outputs an ultra-narrow linewidth Brillouin laser from the first end of the microring resonator. The beam splitter outputs the ultra-narrow linewidth Brillouin laser at a preset ratio. The Brillouin hybrid integrated laser further includes a first mode converter and a second mode converter. The first cavity surface is connected to the Bragg grating through the first mode converter, and the second cavity surface is connected to the first end of the microring resonator through the second mode converter. The beam splitter is located between the second mode converter and the microring resonator. The Bragg grating, microring resonator, beam splitter, first mode converter, and second mode converter are all disposed on a silicon substrate. A first silicon dioxide thin film is grown on the silicon substrate, which serves as the lower cladding of the waveguide. Multiple waveguides for forming the Bragg grating, beam splitter, microring resonator, first mode converter, and second mode converter are disposed on the first silicon dioxide thin film. The waveguide corresponding to each component of the Bragg grating, beam splitter, microring resonator, first mode converter, and second mode converter is made of Si3N4 material and serves as an optical transmission channel. A second silicon dioxide thin film is disposed on the waveguide corresponding to each component of the Bragg grating, beam splitter, microring resonator, first mode converter, and second mode converter, which serves as the upper cladding of the waveguide. The Bragg grating, beam splitter, microring resonator, first mode converter, and second mode converter are fabricated using CMOS technology. Along the direction from the Bragg grating to the microring resonator, the length of the Brillouin hybrid integrated laser is no greater than 1 cm; On-chip integration of Brillouin hybrid integrated lasers.

2. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The material of the Bragg grating is silicon nitride.

3. The Brillouin hybrid integrated laser according to claim 2, characterized in that, The Bragg grating includes a spaced-apart strip waveguide and a plurality of grating pillars. One end of the strip waveguide is connected to the first cavity surface, and the plurality of grating pillars are located on both sides of the strip waveguide. The plurality of grating pillars located on each side of the strip waveguide are spaced apart along the extension direction of the strip waveguide.

4. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The material of the microring resonator is silicon nitride.

5. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The beam splitter outputs a beam with a linewidth in the range of 1Hz to 100Hz according to a preset ratio.

6. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The Brillouin hybrid integrated laser also includes a heat sink, and the gain chip is disposed on the heat sink.

7. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The first cavity surface has an anti-reflection membrane.

8. The Brillouin hybrid integrated laser according to claim 1, characterized in that, The Bragg grating is a high-reflectivity Bragg grating.

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