Brillouin hybrid integrated laser

Abstract

The invention relates to the technical field of lasers, in particular to a Brillouin hybrid integrated laser, which comprises a gain chip; the Bragg grating is connected with the first cavity surface; the first end of the micro-ring resonator is connected with the second cavity surface; the beam splitter is located between the micro-ring resonator and the gain chip; wherein the gain chip is used for generating spontaneous radiation light, the Bragg grating and the low-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 the second cavity surface, the micro-ring resonator generates a stimulated Brillouin scattering effect to generate Stokes light, and the Stokes light is transmitted to the Bragg grating and the low-reflection film. The micro-ring resonator performs mode selection amplification on the Stokes light and outputs ultra-narrow linewidth Brillouin laser, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset proportion. According to the Brillouin hybrid integrated laser, the integration level and the compactness of the Brillouin hybrid integrated laser are improved while it is guaranteed that the Brillouin hybrid integrated laser has excellent performance.

Description

Technical Field

[0001] The invention belongs to the technical field of lasers, and in particular relates to a Brillouin hybrid integrated laser. Background Art

[0002] Semiconductor lasers play a vital role in the field of atomic detection, especially in high-precision spectral analysis and quantum manipulation. These applications require laser light sources with ultra-narrow linewidth, high coherence and low noise characteristics to ensure precise atomic state manipulation and detection efficiency. In the field of ultra-narrow linewidth laser generation, stimulated Brillouin scattering (SBS) has been proven to be an effective method to achieve high-purity spectral output. The stimulated Brillouin scattering effect is an important nonlinear optical phenomenon, which refers to the light scattering phenomenon caused by the interaction between the light wave incident on the optical medium and the elastic acoustic wave in the medium. The statistical thermal motion of a large number of particles in the optical medium will generate elastic acoustic waves, which will cause the density of the optical medium to change periodically with time and space, thereby causing the refractive index of the optical medium to change periodically with time and space. Therefore, the acoustic vibration medium can be regarded as a moving grating. In this way, when a beam of light waves with a frequency of ω passes through the optical medium, it will generate a frequency of ω in the optical medium. s coherent sound waves, and at the same time generate frequencies (ω-ω s The scattered light waves, known as Stokes light, propagate in specific directions. This phenomenon, which occurs only when the incident light intensity exceeds a certain value, is called stimulated Brillouin scattering (SBS). With SBS, the phase noise of the pump light is greatly suppressed by the combined effects of cavity feedback and phonon oscillations, with only a small portion shifted to the phase of the Stokes light. Consequently, the output Brillouin laser linewidth is significantly suppressed.

[0003] Traditionally, Brillouin semiconductor lasers are primarily based on erbium-doped fiber amplifiers (EDFAs) and specific waveguide structures that generate Brillouin laser light through stimulated Brillouin scattering. These waveguide structures can be chalcogenide glass waveguides (e.g., As2S3 waveguides) or silicon-on-insulator (SOI) waveguides. However, these technologies suffer from 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 hybrid integrated laser, which 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.

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

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

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

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

[0009] Furthermore, 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 first cavity surface, the plurality of grating columns are located on both sides of the strip waveguide, and the plurality of grating columns located on each side of the strip waveguide are arranged at intervals along the extension direction of the strip waveguide.

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

[0011] Furthermore, the line width of the light beam output by the beam splitter according to a preset ratio is within the range of 1 Hz to 100 Hz.

[0012] Furthermore, the Brillouin hybrid integrated laser further includes a heat sink, and the gain chip is arranged on the heat sink.

[0013] Furthermore, the first cavity surface has an anti-reflection film.

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

[0015] Furthermore, the Bragg grating is a highly reflective Bragg grating.

[0016] Compared with the prior art, the invention can achieve 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 is integrated together by coupling a spot size converter (SSC), which is conducive to reducing the volume of the Brillouin hybrid integrated laser and reducing the preparation cost of the Brillouin hybrid integrated laser. Specifically, 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 light field confinement ability, which is conducive to achieving low threshold lasing and ensuring a small device size. In addition, the Si3N4 material is compatible with CMOS (Complementary Metal Oxide Semiconductor) technology, suitable for large-scale integration, and has excellent thermal stability and mechanical strength, which is conducive to realizing the integrated arrangement of the Brillouin hybrid integrated laser on the chip and improving the reliability of the Brillouin hybrid integrated laser. The Bragg grating is used as a filter element to provide a specific mode of optical feedback to the gain chip to achieve linewidth narrowing, ultimately obtaining narrow-linewidth pump light for stimulating the stimulated Brillouin scattering effect. The microring resonator is used to stimulate the stimulated Brillouin scattering effect to achieve the output of a stable single-mode narrow-linewidth Brillouin laser. The various components of the Brillouin hybrid integrated laser provided by the present invention are relatively small in size. Therefore, the layout of the Brillouin hybrid integrated laser is more compact and can be easily packaged into a tube shell to form a modular, highly integrated Brillouin hybrid integrated laser. The Brillouin hybrid integrated laser has lower transmission loss and is easily compatible with existing CMOS processes. It not only solves the problems of excessive size, complex preparation, and low integration of lasers in the prior art, but also improves the stability and performance of the laser system, which is conducive to meeting the demand for high-quality laser sources for atomic detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying 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 of the present invention. DETAILED DESCRIPTION

[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 hybrid integrated 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 hybrid integrated 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 expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

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

[0027] refer to Figure 1 The Brillouin hybrid integrated 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 second cavity surface has a low-reflection film; a Bragg grating 2, the Bragg grating 2 is connected to the first cavity surface; a microring resonator 1, the first end of the microring resonator 1 is connected to the second cavity surface; a beam splitter 7, the beam splitter 7 is located between the microring resonator 1 and the gain chip 3; wherein, the gain chip 3 is used to generate spontaneous radiation light, the Bragg grating 2 and the low-reflection film constitute a resonant cavity, the spontaneous radiation light is processed by the resonant cavity to form pump light, the pump light is injected into the microring resonator 1 through the second cavity surface, the microring resonator 1 undergoes stimulated Brillouin scattering effect, and generates Stokes light. The microring resonator 1 performs mode selection and amplification on the Stokes light, and outputs ultra-narrow linewidth Brillouin laser from the first end of the microring resonator 1, and the beam splitter 7 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, provided that it is achievable, the higher the preset ratio, the better.

[0029] In some embodiments, the Bragg grating is a highly reflective Bragg grating having a reflectivity greater than 99%. It should be noted that, as far as practicable, the higher the reflectivity of the highly reflective Bragg grating, the better.

[0030] It should be noted that the Bragg grating 2 in the present invention has a feedback function of a specific mode of light, and the microring resonator 1 supports the 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 strip waveguide and multiple grating posts arranged at intervals. One end of the strip waveguide is connected to the first cavity facet. The multiple grating posts are located on both sides of the strip waveguide, and the multiple grating posts on each side of the strip waveguide are spaced apart along the extension direction of the strip waveguide. The filtering bandwidth and coupling strength of the Bragg grating 2 can be adjusted by varying the distance between the grating posts and the strip waveguide. This structure of the Bragg grating 2 has the characteristics of a low 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 the present invention utilizes the narrowband filtering characteristics of the Bragg grating 2 to obtain narrow-linewidth pump light 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 traditional Brillouin hybrid integrated lasers based on optical fiber structures, the present invention significantly simplifies the structure of the Brillouin hybrid integrated laser, which is conducive to reducing the volume of the Brillouin hybrid integrated laser. The use of silicon nitride to form the Bragg grating 2 and the microring resonator 1 is compatible with existing CMOS processes, allowing for a compact layout in terms of device size. This allows the Brillouin hybrid integrated laser to be packaged in a butterfly tube shell, thereby achieving a highly compact and highly integrated modular laser.

[0035] It should be noted that the gain chip 3 needs to adopt a quantum well structure. The gain chip 3 has a wide amplified spontaneous emission (ASE) spectrum output characteristic and is used as an active gain medium. The second cavity surface of the 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 and the Bragg grating 2 together form a resonant cavity to achieve 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. The broadband light source characteristics of the gain chip 3 lay the foundation for subsequent wavelength selection and nonlinear processing. The compactness and high efficiency of the gain chip 3 make the Brillouin hybrid integrated laser formed by it miniaturized and low-power.

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

[0037] Bragg grating 2 is the core wavelength selection device in the Brillouin hybrid integrated laser. Through its high-precision periodic refractive index modulation structure, Bragg grating 2 can achieve efficient reflection of light of a specific wavelength. Light of a specific wavelength is light that meets the Bragg resonance conditions, and light of other wavelengths does not meet the Bragg resonance conditions. Light that meets the Bragg resonance conditions needs to be fed back to the gain chip. The specific wavelength is the wavelength of the pump light. The efficient reflection of Bragg grating 2 for light of a specific wavelength not only ensures the stability of the output wavelength of the Brillouin hybrid integrated laser, but also effectively suppresses the side mode output, thereby achieving 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 light mode. Therefore, Bragg grating 2 can be used as a filter device to provide optical feedback of a specific mode to achieve linewidth narrowing, and ultimately obtain narrow-linewidth pump light to stimulate 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 can optimize the optical feedback path and reduce unnecessary reflection losses. The Bragg grating 2 is used to narrowband filter the broadband spontaneous emission light output by the gain chip 3, extract the target pump wavelength from it, and suppress the multi-mode 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 hybrid integrated laser, and ensure that the pump light can meet the high quality requirements of subsequent stimulated Brillouin scattering. In the present invention, a high-reflectivity Bragg grating 2 is used as the equivalent resonant cavity surface 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. The Bragg grating 2 made of silicon nitride can provide high-quality optical feedback and precise wavelength selection, which is conducive to significantly compressing the linewidth of the pump light and improving the spectral purity of the pump light. At the same time, it is conducive to enhancing the stability and noise resistance of the Brillouin hybrid integrated laser.

[0041] The microring resonator 1 is a component that realizes the stimulated Brillouin scattering effect. The microring resonator 1 uses its ring waveguide structure to form a resonant mode with a high quality factor, allowing light to circulate multiple times in the ring waveguide structure, greatly improving the light field intensity and the interaction efficiency between light and the medium. When high-intensity pump light passes through the microring resonator 1, it interacts with the acoustic waves in the ring waveguide structure to generate Stokes light with a downshifted frequency. In other words, the microring resonator 1, as a nonlinear optical element of the Brillouin hybrid integrated laser, has a high quality factor and low optical loss characteristics that can confine the light field within 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 the interaction between this strong light and phonons can effectively amplify the Stokes light of 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, microring resonators using silicon nitride can significantly enhance Brillouin gain while lowering the threshold for Brillouin lasing, achieving highly efficient Brillouin laser output. This allows Brillouin hybrid integrated lasers to maintain stable output performance even under extreme conditions. The natural linewidth compression mechanism of stimulated Brillouin scattering allows the laser linewidth to be narrowed to the kHz or even Hz level, which is particularly important for high-precision applications such as atomic detection.

[0043] Since the stimulated Brillouin scattering effect will produce Stokes light in the opposite direction of pump light propagation, 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 (splitting ratio greater than 99:1) is introduced to effectively isolate the forward and reverse-propagating optical signals, reduce the impact of the reverse-propagating Stokes light on the pump light, avoid unnecessary interference, and ensure the purity and stability of the output Brillouin laser.

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

[0045] The main function of the first mode spot converter 5 and the second mode spot 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 accurately matching the mode field distribution between the gain chip 3 and the Bragg grating 2, and by accurately 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 the Brillouin hybrid integrated laser including the first spot converter 5 and the second spot converter 6, the gain chip 3 generates a broad spectrum of spontaneous emission light, which is coupled to the Bragg grating 2 through the first spot converter 5. The Bragg grating 2 extracts the single-mode narrow-linewidth pump light through wavelength selective feedback and feeds it back to the microring resonator 1. The narrow-linewidth pump light is injected into the microring resonator 1, generating an SBS effect, causing the light wave to interact with the sound wave to generate Stokes light with a downward frequency shift. The microring resonator 1 performs mode-selective amplification on the Stokes light and outputs an ultra-narrow linewidth Brillouin laser. The beam splitter 7 outputs the ultra-narrow linewidth Brillouin laser in proportion, while suppressing the interference of the reverse-propagating Brillouin laser on the pump light.

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

[0048] In some embodiments, the Brillouin hybrid integrated laser further includes a heat sink 4, on which the gain chip 3 is disposed. The heat sink 4 is used to quickly dissipate heat generated during 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 first cavity surface has an antireflection film. The antireflection film is used to reduce the loss of coupling between the gain chip 3 and the Bragg grating 2, and can effectively suppress the Fabry-Perot (FP) effect caused by the reflection of the first cavity surface, thereby ensuring high-quality output of the pump light. 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 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 hybrid integrated laser along the direction of the Bragg grating 2 pointing to the microring resonator 1 is no more than 1 cm.

[0051] In some embodiments, the materials of the Bragg grating 2, the beam splitter 7, the microring resonator 1, the first spot converter 5 and the second spot converter 6 all include Si3N4, and the Bragg grating 2, the microring resonator 1, the beam splitter 7, the first spot converter 5 and the second spot converter 6 are all arranged on a silicon-based substrate, a first silicon dioxide film is grown on the silicon-based substrate, the first silicon dioxide film is used to serve as a lower cladding of the waveguide, and a plurality of waveguides for forming the Bragg grating 2, the beam splitter 7, the microring resonator 1, the first spot converter 5 and the second spot converter 6 are arranged on the first silicon dioxide film. The waveguide corresponding to each component of the Bragg grating 2, the beam splitter 7, the microring resonator 1, the first spot converter 5 and the second spot converter 6 can all be made of Si3N4 material, and the waveguide is used as an optical transmission channel. A second silicon dioxide film is provided on the waveguide corresponding to each component of the Bragg grating 2, the beam splitter 7, the microring resonator 1, the first spot converter 5 and the second spot converter 6, and the second silicon dioxide film is used to serve as an upper cladding of the waveguide. In this way, the Bragg grating 2, the beam splitter 7, the microring resonator 1, the first spot mode converter 5 and the second spot mode converter 6 can be prepared using the existing CMOS process, which not only realizes the small-volume integration of the Brillouin hybrid integrated laser, but also reduces the preparation difficulty and cost.

[0052] The Brillouin hybrid integrated laser proposed in the present invention has high compactness and integration. Specifically, by placing the Bragg grating 2 on the first cavity surface of the gain chip 3 and coating the second cavity surface of the gain chip 3 with a low-reflection film, a more compact layout is achieved. The Bragg grating 2, the microring resonator 1, the beam splitter 7, the first mode spot converter 5 and the second mode spot converter 6 can all be made of Si3N4 material, which can control the total length of the Brillouin hybrid integrated laser to a 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 the manufacturing cost and process complexity of the Brillouin hybrid integrated laser. Specifically, Si3N4 is compatible with CMOS technology, which means that it can be mass-produced using existing semiconductor production lines, which is conducive to reducing costs. This compatibility provides broad space for future integrated development, allowing the Brillouin hybrid integrated laser to be seamlessly integrated with other electronic components to form a multifunctional optoelectronic system. Compared with traditional Brillouin hybrid integrated 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 the Brillouin hybrid integrated laser simpler and more economical; the Brillouin hybrid integrated 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 hybrid integrated laser provided by the present invention can significantly improve the accuracy and efficiency of atomic detection with its ultra-narrow linewidth, high coherence and low noise characteristics, meeting the needs of high-end scientific research and industrial applications.

[0053] 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.

[0054] 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 hybrid integrated laser, characterized in that: include: A gain chip, the gain chip having a first cavity surface and a second cavity surface arranged opposite to each other, the second cavity surface having a low-reflection film; A Bragg grating connected to the first cavity facet; a microring resonator, wherein a first end of the microring resonator is connected to the second cavity surface; a beam splitter, the beam splitter being located between the microring resonator and the gain chip; The gain chip is used to generate spontaneous radiation light, the Bragg grating and the low-reflection film constitute a resonant cavity, the spontaneous radiation 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 effect to generate Stokes light, the microring resonator performs mode selection and amplification on the Stokes light, and outputs ultra-narrow linewidth Brillouin laser from the first end of the microring resonator, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset ratio.

2. The Brillouin hybrid integrated laser according to claim 1, characterized in that: The Brillouin hybrid integrated laser also includes a first spot mode converter and a second spot mode converter. The first cavity surface is connected to the Bragg grating through the first spot mode converter, and the second cavity surface is connected to the first end of the microring resonator through the second spot mode converter. The beam splitter is located between the second spot mode converter and the microring resonator.

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

4. The Brillouin hybrid integrated laser according to claim 3, characterized in that: 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 first cavity surface, the plurality of grating columns are located on both sides of the strip waveguide, and the plurality of grating columns located on each side of the strip waveguide are arranged at intervals along the extension direction of the strip waveguide.

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

6. The Brillouin hybrid integrated laser according to claim 1, characterized in that: The line width of the light beam output by the beam splitter according to a preset ratio is within the range of 1 Hz to 100 Hz.

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

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

9. The Brillouin hybrid integrated laser according to claim 1, characterized in that: Along the direction from the Bragg grating to the microring resonator, the length of the Brillouin hybrid integrated laser is no more than 1 cm.

10. The Brillouin hybrid integrated laser according to claim 1, characterized in that: The Bragg grating is a highly reflective Bragg grating.

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