A fiber coupled semiconductor laser spectrum combining device with a double-layer optical path structure

Abstract

The application relates to the technical field of semiconductor lasers, in particular to a fiber-coupled semiconductor laser spectrum beam combining device with a double-layer optical path structure. The device mainly comprises a spatial arrangement module unit, a dense spectrum beam combining unit and a fiber coupling unit. The spatial arrangement module unit is used for spatially combining and regularly arranging the light beams of a plurality of semiconductor laser output modules. The dense spectrum beam combining unit combines the light beams through a first reflector, a second reflector, a collimating lens, a transform lens, a transmission type diffraction grating and an output coupling mirror, wherein the double-layer optical path design effectively compresses the system volume by using optical path folding. The fiber coupling unit efficiently couples the combined light beams into the optical fiber through an aspheric lens, realizing flexible transmission of the laser. By optimizing the optical path layout and component integration, the compactness and output efficiency of the device are significantly improved, and high-power and high-brightness laser output is ensured.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, and more specifically to a fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure. Background Technology

[0002] Semiconductor lasers, due to their advantages such as high electro-optical conversion efficiency, small size, light weight, high reliability, and long lifespan, have been widely used in various fields including medicine, materials processing, and aerospace. Among them, 800 nm semiconductor lasers, with their combination of low atmospheric transmission loss and high photoelectric conversion efficiency of GaAs-based laser cells, have significant advantages in laser power transfer and laser illumination applications. However, due to the inherent characteristics of their light-emitting structure, semiconductor laser output beams typically exhibit strong asymmetry, resulting in limited beam quality and lower brightness, thus restricting their application in long-distance, high-power laser power transfer systems. To overcome these limitations, in 2000, MIT Lincoln Laboratory first proposed using a grating external cavity method to spectrally combine semiconductor laser arrays or multiple fiber lasers. Extensive research both domestically and internationally has shown that grating external cavity spectral combining technology has significant advantages in improving the beam quality of semiconductor lasers and achieving high-brightness output, making it one of the most effective beam combining techniques currently available. Meanwhile, optical fibers have excellent flexible transmission capabilities and environmental adaptability. Therefore, efficiently coupling the output beams of multiple semiconductor laser units into optical fibers through beam combining technology, thereby further improving the output power and brightness of the system, has become one of the main technical approaches to achieve high-performance applications of semiconductor lasers.

[0003] However, traditional spectral beam combining structures typically require long optical transmission paths, resulting in large system volumes that hinder miniaturization and compactness. Furthermore, their output methods offer limited flexibility in terms of system layout and application scenario adaptation, thus limiting the system's adoption in highly integrated and flexible application scenarios.

[0004] Therefore, existing technologies still need further development. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a fiber-coupled semiconductor laser spectral beam combining device with a dual-layer optical path structure to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure, comprising: Spatial arrangement module unit, dense spectral bundle combining unit, and fiber optic coupling unit; The spatial arrangement module unit is used to output the beams that have been spatially combined by each module in a neat and dense arrangement, and the output beams enter the dense spectral beam combining unit. The dense spectral beam combining unit is used to perform spectral beam combining on the densely arranged beam output by the spatial arrangement module unit, and the beam after spectral beam combining enters the fiber coupling unit. The fiber coupling unit is used to couple the beam output from the dense spectral combining unit into the optical fiber, thereby achieving fiber coupling output.

[0007] Specifically, the spatial arrangement module unit includes a semiconductor laser output module group and a reflection component; the semiconductor laser output module group is densely arranged in an array; the reflection component is located in the independent optical path transmission path of the corresponding semiconductor laser output module, and is used to correct the optical path and ensure optical path consistency.

[0008] Specifically, the semiconductor laser output module group includes a semiconductor laser emitting unit, a fast-axis collimating lens group, a slow-axis collimating lens group, and a small reflection component; the beam emitted by the semiconductor laser emitting unit is collimated sequentially by the fast-axis collimating lens group and the slow-axis collimating lens group, and then reflected and output by the small reflection component.

[0009] Specifically, the semiconductor laser emitting units are arranged in a stepped manner, so that the output beams of each unit are spatially parallel and equally spaced.

[0010] Specifically, the small reflective component is arranged in the independent transmission optical path of the corresponding semiconductor laser emitting unit to achieve optical path folding and ensure optical path compactness.

[0011] Specifically, the reflective component is set at a predetermined angle relative to the incident direction of the output beam of the semiconductor laser output module group, for reflecting the beam to the dense spectral beam combining unit.

[0012] Specifically, the dense spectral beam combining unit includes a first reflecting mirror, a second reflecting mirror, a collimating lens, a third reflecting mirror, a transforming lens, a fourth reflecting mirror, a fifth reflecting mirror, a transmission diffraction grating, and an output coupling mirror. After being reflected by the first reflecting mirror, the light beam is sequentially folded and processed by the second reflecting mirror, the collimating lens, the third reflecting mirror, the transforming lens, the fourth reflecting mirror, and the fifth reflecting mirror, and finally incident on the transmission diffraction grating and the output coupling mirror to achieve spectral beam combining.

[0013] Specifically, the first reflector is used to reflect the light beam output by the spatial arrangement module unit to the second layer of the device, thereby achieving optical path compression.

[0014] Specifically, the collimating lens is used to collimate the non-beam-combining direction of the beam to improve beam quality.

[0015] Specifically, the transformation lens is used to converge multiple beams of light to meet the external cavity equivalence conditions.

[0016] Specifically, the output coupling mirror has a reflective film coated on the surface where the combined beam is incident, which is used to reflect part of the beam back along the original path to achieve wavelength locking.

[0017] Specifically, the fiber coupling unit includes an aspherical lens and an optical fiber; the aspherical lens is used to focus the combined beam onto the input end of the optical fiber.

[0018] Specifically, the optical fiber is positioned perpendicular to the incident direction of the focused beam from the aspherical lens to enable flexible laser transmission.

[0019] Specifically, the spatial arrangement module unit is located in the first layer of the device, and the dense spectral combining unit and the fiber coupling unit are located in the second layer of the device, forming a double-layer optical layout.

[0020] Specifically, the first, second, third, fourth, and fifth reflectors are all coated with a high-reflectivity film on the surface where the light beam is incident, in order to reduce power loss.

[0021] Specifically, the small reflective component is coated with a high-reflectivity film on the surface where the light beam is incident, in order to ensure the efficiency of the optical path transmission.

[0022] Beneficial effects: The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure provided by this invention brings many significant benefits through innovative optical design and hierarchical layout.

[0023] First, the device adopts a unique dual-layer optical path structure, placing the spatial arrangement module unit in the first layer, while the dense spectral beam combining unit and fiber coupling unit are integrated in the second layer. Multiple mirrors are used to intelligently fold the optical path, compressing the traditional long linear optical path into a compact Z-shaped layout. This significantly reduces the overall size and volume of the system without sacrificing any optical functions, effectively overcoming the shortcomings of traditional beam combining devices that are bulky and have low integration. This makes the device easier to install in space-constrained environments, such as portable medical devices or mobile processing platforms.

[0024] Secondly, through the optimized design of the spatial arrangement module unit, multiple semiconductor laser output modules are arranged in a dense array, ensuring the regularity and consistency of the input beam, laying a good foundation for subsequent spectral beam combining. This not only improves the beam combining efficiency, but also significantly enhances the brightness and power stability of the output beam.

[0025] Furthermore, the device incorporates a highly efficient fiber coupling unit. The combined beam is directly coupled into the optical fiber through an aspherical lens. Utilizing the flexible transmission characteristics of the fiber, long-distance, low-loss laser transmission is achieved, greatly expanding the adaptability of application scenarios and reducing the impact of environmental interference on beam quality. In terms of optical path processing, the coordinated work of the collimating lens and the transforming lens effectively improves the asymmetry of the beam, making the beam parameters in the fast and slow axis directions tend to be balanced, and the output beam spot is more conducive to fiber coupling. The introduction of the external cavity feedback mechanism, through the wavelength locking function of the output coupling mirror, stabilizes the output spectrum and further improves the reliability of the system.

[0026] Overall, this invention not only achieves miniaturization and high integration of the device, but also significantly improves output power, brightness, and application flexibility by optimizing the optical path and component integration, providing a reliable and efficient solution for high-performance applications of semiconductor lasers and having broad market prospects. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure and optical path of the present invention provided in a specific embodiment of the present invention.

[0028] Figure 2 This is a top view of the overall structure and optical path of the present invention as provided in a specific embodiment of the present invention.

[0029] Figure 3 This is a side view of the overall structure and optical path of the present invention as provided in a specific embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the spatial arrangement module unit structure and optical path provided in a specific embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram of the structure and optical path of a single semiconductor laser output module provided in a specific embodiment of the present invention.

[0032] The above figures contain the following reference numerals: 1. Spatial arrangement module unit; 2. First reflecting mirror; 3. Second reflecting mirror; 4. Collimating lens; 5. Third reflecting mirror; 6. Transforming lens; 7. Fourth reflecting mirror; 8. Fifth reflecting mirror; 9. Transmission diffraction grating; 10. Output coupling mirror; 11. Aspherical lens; 12. Optical fiber; 101. Semiconductor laser output module; 102. Reflection assembly; 101-1. Semiconductor laser emitting unit; 101-2. Fast axis collimating lens group; 101-3. Slow axis collimating lens group; 101-4. Small reflection assembly. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0034] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0035] Please see Figures 1-5 This invention provides a fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure, comprising: Spatial arrangement module unit 1, dense spectral beam combining unit 2-10 and optical fiber coupling unit 11-12; The spatial arrangement module unit 1 is used to output the beams of spatial beam combining completed by each module in a neat and dense arrangement, and the output beams enter the dense spectral beam combining unit. The dense spectral beam combining unit 2-10 is used to perform spectral beam combining on the densely arranged beam output by the spatial arrangement module unit, and the beam after spectral beam combining enters the fiber coupling unit. The fiber coupling units 11-12 are used to couple the beam output from the dense spectral combining unit into the optical fiber, thereby achieving fiber coupling output.

[0036] For further details, please refer to Figure 1 The dense spectral beam combining unit 2-10 is used to spectrally combine the densely arranged beams output from the spatial arrangement module unit. The beams after spectral combining enter the fiber coupling unit. It includes a first reflecting mirror 2, a second reflecting mirror 3, a collimating lens 4, a third reflecting mirror 5, a transformation lens 6, a fourth reflecting mirror 7, a fifth reflecting mirror 8, a transmission diffraction grating 9, and an output coupling mirror 10. The densely arranged beams output from the spatial arrangement module unit 1 are reflected by the first reflecting mirror 2 to the second layer, and then folded by the second reflecting mirror 3 before entering the collimating lens 4. The collimating lens 4 achieves collimation in the non-combining direction (slow axis direction). The collimated beams are reflected by the third reflecting mirror 5 and then enter the transformation lens 6. The beams converged by the transformation lens 6 are folded by the fourth reflecting mirror 7 and the fifth reflecting mirror 8 in sequence, and finally converge at different incident angles to the transmission diffraction grating 9. After diffraction by the grating (diffraction angle is the Littrow angle), the beams are wavelength locked by the output coupling mirror 10, thereby achieving spectral combining.

[0037] Furthermore, such as Figure 2The diagram shown is a top view and optical path schematic of a fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure provided in a specific embodiment of the present invention. Detailed explanations of its system structure and optical path transmission process are also provided. Figure 1 .

[0038] Furthermore, such as Figure 3 The diagram shown is a side view and optical path schematic of a fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure provided in a specific embodiment of the present invention. Detailed explanations of its system structure and optical path transmission process are also provided. Figure 1 .

[0039] Furthermore, such as Figure 4 The diagram shows the spatial arrangement module unit structure and optical path of the present invention, including a semiconductor laser output module group 101 and a reflective component 102. The reflective component 102 is set at a 45° angle relative to the incident direction of the output beam of the semiconductor laser output module group 101, and its reflective film has a reflectivity greater than 99.7%. After being reflected by the reflective component 102, the beam emitted from the semiconductor laser output module group 101 is incident parallel and equally spaced into the rear dense spectral combining unit 2-10 to achieve spectral combining. The combined beam is then finally incident into the fiber coupling unit 11-12 to achieve fiber coupling output.

[0040] It should be further explained that the spatial arrangement module unit 1 is located in the first layer of the device. Its core function is to form a regular spatial distribution of the output beam by compactly arranging multiple laser output modules. The dense spectral beam combining unit 2-10 and the fiber coupling unit 11-12 are located in the second layer, and the system volume is compressed through the optical path folding design. The beam output from the spatial arrangement module unit 1 is first incident on the first reflecting mirror 2, and after reflection, it enters the second layer optical path; the beam is then folded by the second reflecting mirror 3, collimated in the slow axis direction by the collimating lens 4, and then reflected by the third reflecting mirror 5 to the transformation lens 6 to achieve beam convergence; the converged beam is then folded sequentially by the fourth reflecting mirror 7 and the fifth reflecting mirror 8, and incident on the transmission diffraction grating 9 at different angles. The diffracted light is wavelength locked and beam combined by the output coupling mirror 10.

[0041] Furthermore, the combined beam is finally converged by the aspherical lens 11 and coupled into the optical fiber 12. The entire device, through a dual-layer optical path layout, significantly shortens the optical path length of traditional spectral beam combining devices. The spacing and angles of key components require precise control. For example, the sum of the optical path from the center beam of the spatial arrangement module unit 1 to the first reflecting mirror 2 and the optical path after reflection to the collimating lens 4 must be equal to the focal length of the collimating lens 4 to ensure collimation. The placement of the transmission diffraction grating 9 must satisfy the Littrow angle condition, the calculation formula of which is: in, Indicates the angle of incidence of the central beam. Indicates the diffraction angle. Indicates the Littrow angle. Indicates the wavelength of the center beam. This represents the grating period of a transmission diffraction grating. The application of this formula ensures that the grating operates at its highest diffraction efficiency. Preferably, It is 808 nm. Select according to the actual grating model, for example, when the grating period is 1200 lines / mm. It is 833.3 nm, calculated as follows The preferred value is approximately 29.0 degrees, which is based on common semiconductor laser wavelengths and grating parameters to achieve high beam combining efficiency.

[0042] Understandably, this solution effectively compresses the system volume through a dual-layer optical path structure, overcoming the shortcomings of traditional devices such as large size and low integration. The dense arrangement of spatially arranged module unit 1 increases the beam input density, and combined with the optical path folding design, the optical path length is reduced while maintaining functionality. The fiber coupling units 11-12 utilize the flexible transmission characteristics of optical fibers to reduce power loss, ultimately achieving high-power, high-brightness laser output, meeting the compactness and efficiency requirements of applications such as medical and materials processing.

[0043] Specifically, it includes a semiconductor laser output module group 101 and a reflection component 102; the semiconductor laser output module group 101 is densely arranged in an array; the reflection component 102 is located in the independent optical path transmission path of the corresponding semiconductor laser output module, and is used to correct the optical path and ensure optical path consistency.

[0044] It should be further explained that the semiconductor laser output module group 101 adopts a "V"-shaped array arrangement, for example, consisting of n modules, each module containing m laser emitting units. The modules are arranged sequentially from short-wavelength to long-wavelength, forming an ordered angular distribution. The reflection component 102 consists of multiple mirrors, each mirror is set at a 45-degree angle relative to the incident direction of the output beam of the corresponding module, and its reflecting surface is coated with a high-reflectivity film (reflectivity greater than 99.7%), used to reflect the beam to the dense spectral beam combining unit 2-10, while correcting the external cavity optical path of each optical path to ensure that all beam path lengths are consistent. Preferably, the number of modules n is 10 and the number of laser units m is 15. This preferred value is based on the requirements of common high-power applications, balancing output power and system complexity; the 45-degree angle design of the reflection component 102 simplifies optical path adjustment and avoids beam interference.

[0045] Understandably, the “V”-shaped arrangement of the semiconductor laser output module group 101 enhances spatial compactness, and the optical path correction function of the reflection component 102 ensures optical path consistency during beam combining, thereby improving the stability and efficiency of spectral beam combining and reducing aberrations and power loss.

[0046] Specifically, it includes a semiconductor laser emitting unit 101-1, a fast-axis collimating lens group 101-2, a slow-axis collimating lens group 101-3, and a small reflection component 101-4; the beam emitted by the semiconductor laser emitting unit 101-1 is collimated sequentially by the fast-axis collimating lens group 101-2 and the slow-axis collimating lens group 101-3, and then reflected and output by the small reflection component 101-4.

[0047] It should be further explained that the semiconductor laser emitting unit 101-1 consists of multiple laser chips arranged in a stepped manner. By controlling the height and position of the steps, the output beams of each unit are made parallel and equally spaced. The fast-axis collimating lens group 101-2 consists of multiple fast-axis collimating lenses, each of which is set perpendicular to the fast-axis direction of the beam to reduce the fast-axis divergence angle. The slow-axis collimating lens group 101-3 consists of slow-axis collimating lenses for collimation in the slow-axis direction. The small reflecting component 101-4 consists of multiple small reflecting mirrors distributed in a stepped manner. Each reflecting mirror is at a 45-degree angle relative to the incident direction of the beam, and the reflecting surface is coated with a high-reflectivity film (reflectivity greater than 99.9%) to fold the optical path and output to the reflecting component 102. Preferably, the focal length of the fast-axis collimating lens is 0.5 mm, and the focal length of the slow-axis collimating lens is 10 mm. This preferred value is based on the fast and slow axis divergence angle characteristics of a typical semiconductor laser to ensure that the quality of the collimated beam is approximately symmetrical.

[0048] Furthermore, such as Figure 5 The diagram shows the structure and optical path of a single semiconductor laser output module of the present invention, including a semiconductor laser emitting unit 101-1, a fast-axis collimating lens group 101-2, a slow-axis collimating lens group 101-3, and a small reflector component 101-4. The semiconductor laser emitting unit 101-1 consists of m laser emitting units (chips) arranged in a stepped configuration. By precisely controlling the position and height of each step, the laser emitting units are closely spaced, ultimately outputting parallel and equally spaced beam groups. Based on actual application requirements and output results, the focal lengths of the fast-axis collimating lens in the fast-axis collimating lens group 101-2 and the slow-axis collimating lens in the slow-axis collimating lens group 101-3 are rationally selected. The beam output from the semiconductor laser emitting unit 101-1 is collimated in the fast-axis direction (beam combining direction) and the slow-axis direction (non-beam combining direction) successively by the fast-axis collimating lens group 101-2 and the slow-axis collimating lens group 101-3, reducing the fast and slow axis divergence angles of each beam and improving beam quality.

[0049] Specifically, the small reflective components 101-4 are also arranged in a stepped pattern, and their incident surface reflectivity is greater than 99.9%. The laser emitting units of each laser output module are arranged in the same way, and the fast-axis collimating lens and the slow-axis collimating lens have the same structure.

[0050] Understandably, the stepped arrangement and dual collimating lens group design improve beam asymmetry, and the optical path folding of the small reflector 101-4 further compresses the module volume, improving the overall compactness and beam quality of the spatial arrangement module unit 1, laying the foundation for subsequent beam combining.

[0051] Specifically, the semiconductor laser emitting units 101-1 are arranged in a stepped manner, so that the output beams of each unit are parallel and equally spaced in space.

[0052] It should be further explained that the stepped arrangement is achieved by precisely controlling the longitudinal and lateral offset of each laser chip. For example, adjacent chips are offset by 0.5 mm in the slow axis direction and closely arranged in the fast axis direction. The offset amount is determined according to the beam spacing requirements. Preferably, the step height difference is 0.2 mm. This preferred value is based on the standard chip size and beam overlap requirements to avoid shading and ensure uniform beam spot.

[0053] Understandably, this arrangement achieves a dense distribution of beams, increases spatial beam combining density, and reduces module size, thus contributing to device miniaturization.

[0054] Specifically, the small reflective component 101-4 is arranged in the independent transmission optical path of the corresponding semiconductor laser emitting unit 101-1 to realize optical path folding and ensure optical path compactness.

[0055] It should be further noted that each small reflector component 101-4 corresponds independently to a laser emitting unit, and the mirror angle needs to be precisely calibrated to 45 degrees to ensure that the reflected beam is output in parallel. Preferably, the reflector size is 2 mm × 2 mm. This preferred value is based on the beam diameter and spatial constraints to avoid excessive volume.

[0056] Understandably, the independent optical path design avoids crosstalk, and the optical path folding reduces the module length and enhances the consistency of the units, thereby improving the beam combining accuracy.

[0057] Specifically, the reflective component 102 is set at a predetermined angle relative to the incident direction of the output beam of the semiconductor laser output module group 101, for reflecting the beam to the dense spectral beam combining unit.

[0058] It should be further noted that the predetermined angle is preferably 45 degrees. This angle is based on optical path geometry optimization, ensuring that the reflected beam is perpendicularly incident on the first reflecting mirror 2, simplifying the alignment process. The reflecting mirror of the reflecting assembly 102 needs to be coated with a high reflectivity film layer, with a reflectivity greater than 99.7%, to minimize losses.

[0059] Understandably, the 45-degree angle design ensures the efficiency of optical path conversion, and the high-reflectivity film reduces power loss and improves the overall efficiency of the system.

[0060] Specifically, it includes a first reflecting mirror 2, a second reflecting mirror 3, a collimating lens 4, a third reflecting mirror 5, a transforming lens 6, a fourth reflecting mirror 7, a fifth reflecting mirror 8, a transmission diffraction grating 9, and an output coupling mirror 10. After being reflected by the first reflecting mirror 2, the light beam is sequentially folded and processed by the second reflecting mirror 3, the collimating lens 4, the third reflecting mirror 5, the transforming lens 6, the fourth reflecting mirror 7, and the fifth reflecting mirror 8, and finally incident on the transmission diffraction grating 9 and the output coupling mirror 10 to achieve spectral beam combining.

[0061] It should be further explained that the first reflecting mirror 2 is located in the first layer and reflects the light beam to the second layer; the second reflecting mirror 3 further folds the light path and guides the light beam to the collimating lens 4, which collimates the slow axis direction. After collimation, the light beam is reflected by the third reflecting mirror 5 to the transformation lens 6, realizing beam convergence; the converged beam is then folded by the fourth reflecting mirror 7 and the fifth reflecting mirror 8 and incident on the transmission diffraction grating 9 at different incident angles. The diffracted light is fed back and locked to the wavelength by the output coupling mirror 10.

[0062] Furthermore, the critical optical path lengths must meet the following external cavity conditions: the sum of the optical path length from the center beam of the spatial arrangement module unit 1 to the first reflecting mirror 2 and the optical path length after reflection to the collimating lens 4 is equal to the focal length f_1 of the collimating lens 4; the sum of the optical path length from the transformation lens 6 to the fourth reflecting mirror 7 and the optical path length after reflection to the transmission diffraction grating 9 is equal to the focal length f_2 of the transformation lens 6. Preferably, f_1 is 500 mm and f_2 is 800 mm. These preferred values ​​are based on typical beam combining system parameters to ensure beam overlap and wavelength stability. The diffraction efficiency of the transmission diffraction grating 9 must be greater than 97.5%, and the reflectivity of the output coupling mirror 10 is preferably 4.5% (within the range of 3%-6%). This value is determined experimentally to balance feedback intensity and output power.

[0063] Understandably, the multi-layer mirror folding optical path significantly compresses the system size, while the external cavity conditions ensure beam combining efficiency. The optimized reflectivity of the output coupling mirror 10 achieves stable wavelength locking, improving output brightness and power.

[0064] Specifically, the first reflector 2 is used to reflect the light beam output by the spatial arrangement module unit 1 to the second layer of the device, thereby achieving optical path compression.

[0065] It should be further noted that the placement angle of the first reflector 2 should ensure that the reflected beam rises vertically to the second layer, and the mirror reflectivity should be greater than 99.9% to minimize losses. Preferably, the reflector size is 10 mm × 10 mm, selected based on the beam diameter.

[0066] Understandably, this design divides the optical path into two layers, reducing the plane footprint and enhancing the device's compactness.

[0067] Specifically, the collimating lens 4 is used to collimate the non-beam-combining direction of the beam to improve the beam quality.

[0068] It should be further noted that the collimating lens 4 is set perpendicular to the slow axis direction of the beam, has a transmittance greater than 99.9%, and its focal length f_1 must match the optical path. Preferably, f_1 is 500mm, a value based on a typical slow axis divergence angle, ensuring that the divergence angle after collimation is less than 5mrad.

[0069] Understandably, slow-axis collimation reduces beam asymmetry, providing high-quality input for spectral beam combining.

[0070] Specifically, the transformation lens 6 is used to converge multiple beams of light to meet the equivalent conditions of the external cavity.

[0071] It should be further noted that the focal length f_2 of the transforming lens 6 must ensure that the light beams overlap at the transmission diffraction grating 9, with a transmittance greater than 99.9%. Preferably, f_2 is 800 mm, a value based on the grating size and incident angle range, to ensure effective diffraction of all light beams.

[0072] Understandably, the converging design enhances the grating diffraction efficiency, while the external cavity conditions ensure consistent feedback and improve beam combining stability.

[0073] Specifically, the output coupling mirror 10 has a reflective film coated on the surface where the combined beam is incident, which is used to reflect part of the beam back along the original path to achieve wavelength locking.

[0074] It should be further noted that the reflectivity of the reflective film is preferably 4.5%, a value determined through iterative experiments, which ensures both stable feedback and sufficient output power. The mirror surface must be strictly perpendicular to the beam to avoid mode misalignment.

[0075] Understandably, the wavelength locking mechanism improves spectral purity, and the reflectivity optimization balances output and feedback, achieving high-efficiency beam combining.

[0076] Specifically, it includes an aspherical lens 11 and an optical fiber 12; the aspherical lens 11 is used to focus the combined beam onto the input end of the optical fiber 12.

[0077] It should be further noted that the aspherical lens 11 is positioned perpendicular to the beam, and its focal length f must satisfy the fiber coupling condition: in, Indicates the diameter of the focused spot. Indicates the numerical aperture of the optical fiber. Indicates the fiber core diameter. This indicates the divergence angle of the light spot. Calculate using the following formula: in, This indicates the refractive index of air (approximately 1.0). Indicates the refractive index of the fiber core. The value represents the cladding refractive index. Preferably, the fiber core diameter is 100 μm, NA is 0.22, and f is 8 mm. These preferred values ​​are based on typical high-power fiber parameters, ensuring that the spot diameter is smaller than the core diameter and the divergence angle is matched.

[0078] Understandably, the aspherical lens 11 efficiently focuses the beam, and combined with flexible fiber optic transmission, it reduces application scenario limitations and improves system portability and reliability.

[0079] Specifically, the optical fiber 12 is positioned perpendicular to the incident direction of the focused beam of the aspherical lens 11 to achieve flexible transmission of the laser.

[0080] It should be further noted that the input end of the optical fiber 12 is located at the focal plane of the aspherical lens 11, and both ends are coated with anti-reflection coatings (transmittance greater than 99.9%) to reduce coupling loss. Preferably, the length of the optical fiber is 1-10 m, selected based on the required transmission distance.

[0081] Understandably, vertical setups minimize insertion loss, and flexible transmission expands the range of applications, such as remote processing and medical surgery.

[0082] Specifically, the spatial arrangement module unit 1 is located in the first layer of the device, and the dense spectral beam combining unit 2-10 and the optical fiber coupling unit 11-12 are located in the second layer of the device, forming a double-layer optical layout.

[0083] It should be further explained that the dual-layer layout compresses the traditional linear optical path into a Z-shaped structure through optical path folding, and the interlayer distance is preferably 20 mm, which is determined based on the component size and heat dissipation requirements.

[0084] Understandably, this layout significantly reduces size and increases integration, making it suitable for space-constrained scenarios.

[0085] Specifically, the first reflector 2, the second reflector 3, the third reflector 5, the fourth reflector 7, and the fifth reflector 8 are all coated with a high reflectivity film on the surface where the light beam is incident, in order to reduce power loss.

[0086] It should be further noted that the high-reflectivity film layer has a reflectivity greater than 99.9%, and a metal-dielectric film is preferred, optimized based on a wavelength of 808 nm. The mirror angle tolerance must be less than 0.1 degrees to ensure optical path accuracy.

[0087] Understandably, the high-reflectivity film reduces system losses and improves overall efficiency.

[0088] Specifically, the small reflective component 101-4 is coated with a high reflectivity film on the surface where the light beam is incident, in order to ensure the efficiency of optical path transmission.

[0089] It should be further noted that the reflectivity of the film layer is greater than 99.9%, and preferably consistent with that of the reflective component 102, to maintain optical path consistency. The mirror size is customized according to the beam diameter, for example, 1 mm × 1 mm.

[0090] Understandably, this design minimizes internal module losses and ensures consistent beam quality.

[0091] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0092] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure, characterized in that, include: Spatial arrangement module unit (1), dense spectral bundle combining unit (2-10) and fiber optic coupling unit (11-12); The spatial arrangement module unit (1) is used to output the beams of each module that have completed spatial beam combining in a neat and dense arrangement, and the output beams enter the dense spectral beam combining unit. The dense spectral beam combining unit (2-10) is used to perform spectral beam combining on the densely arranged beam output by the spatial arrangement module unit, and the beam after spectral beam combining enters the fiber coupling unit. The fiber coupling unit (11-12) is used to couple the beam output from the dense spectral beam combiner into the optical fiber to achieve fiber coupling output.

2. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 1, characterized in that, The spatial arrangement module unit (1) includes a semiconductor laser output module group (101) and a reflective component (102). The semiconductor laser output module group (101) is densely arranged in an array; The reflective component (102) is located in the independent optical path transmission path of the corresponding semiconductor laser output module, and is used to correct the optical path and ensure optical path consistency.

3. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 2, characterized in that, The semiconductor laser output module group (101) includes a semiconductor laser emitting unit (101-1), a fast-axis collimating lens group (101-2), a slow-axis collimating lens group (101-3), and a small reflection component (101-4). The light beam emitted by the semiconductor laser emitting unit (101-1) is collimated by the fast-axis collimating lens group (101-2) and the slow-axis collimating lens group (101-3) in sequence, and then reflected by the small reflection component (101-4) for output.

4. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 3, characterized in that, The semiconductor laser emitting units (101-1) are arranged in a stepped manner, so that the output beams of each unit are parallel and equally spaced in space.

5. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 3, characterized in that, The small reflective component (101-4) is arranged in the independent transmission optical path of the corresponding semiconductor laser emitting unit (101-1) to realize optical path folding and ensure optical path compactness.

6. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 2, characterized in that, The reflective component (102) is set at a predetermined angle relative to the incident direction of the output beam of the semiconductor laser output module group (101) for reflecting the beam to the dense spectral beam combining unit.

7. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 1, characterized in that, The dense spectral beam combining unit (2-10) includes a first mirror (2), a second mirror (3), a collimating lens (4), a third mirror (5), a transformation lens (6), a fourth mirror (7), a fifth mirror (8), a transmission diffraction grating (9), and an output coupling mirror (10). After being reflected by the first reflecting mirror (2), the light beam is folded and processed sequentially through the second reflecting mirror (3), collimating lens (4), third reflecting mirror (5), transforming lens (6), fourth reflecting mirror (7) and fifth reflecting mirror (8), and finally incident on the transmission diffraction grating (9) and output coupling mirror (10) to achieve spectral beam combining.

8. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 7, characterized in that, The first reflector (2) is used to reflect the light beam output by the spatial arrangement module unit (1) to the second layer of the device to achieve optical path compression.

9. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 7, characterized in that, The collimating lens (4) is used to collimate the non-beam-combining direction of the beam to improve the beam quality.

10. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 7, characterized in that, The transformation lens (6) is used to converge multiple beams to meet the external cavity equivalence conditions.

11. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 7, characterized in that, The output coupling mirror (10) has a reflective film on the surface on which the combined beam is incident, which is used to reflect part of the beam back along the original path to achieve wavelength locking.

12. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 1, characterized in that, The fiber optic coupling unit (11-12) includes an aspherical lens (11) and an optical fiber (12). The aspherical lens (11) is used to focus the combined beam onto the input end of the optical fiber (12).

13. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 12, characterized in that, The optical fiber (12) is set perpendicular to the incident direction of the focused beam of the aspherical lens (11) to achieve flexible transmission of the laser.

14. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 1, characterized in that, The spatial arrangement module unit (1) is located in the first layer of the device, and the dense spectral beam combining unit (2-10) and the optical fiber coupling unit (11-12) are located in the second layer of the device, forming a double-layer optical layout.

15. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 7, characterized in that, The first reflector (2), the second reflector (3), the third reflector (5), the fourth reflector (7) and the fifth reflector (8) are all coated with a high reflectivity film on the surface where the light beam is incident, so as to reduce power loss.

16. The fiber-coupled semiconductor laser spectral combining device with a dual-layer optical path structure according to claim 3, characterized in that, The small reflective component (101-4) is coated with a high reflectivity film on the surface where the light beam is incident, in order to ensure the efficiency of the optical path transmission.

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