A high power multilayer homogenizing laser system

Abstract

The application discloses a high-power multilayer homogenization laser system, comprising: a plurality of laser source modules, and the plurality of laser source modules are arranged alternately and inversely; a combined homogenization module, comprising a mirror group, used for redirecting corresponding array light beams and splicing the array light beams with a previous group of array light beams to form a uniform combined array light spot, and completing first layer homogenization; a microlens homogenization module, comprising an array microlens and a first lens arranged in sequence along an optical path, the array microlens divides the combined array light spot into a plurality of sub-beams, and the first lens makes the sub-beams coincide and superimpose at a phase surface thereof, and completes second layer homogenization; a compensation amplification homogenization module, comprising a compensation mirror arranged at the phase surface of the first lens and a second lens located behind the compensation mirror, the compensation mirror corrects central contraction distortion of the light beams after amplification, and the second lens amplifies and images the light beams after compensation. The problems of beam gaps, uneven energy and amplification distortion in the prior art high-power laser beam combination technology are solved.

Description

Technical Field

[0001] This application relates to the technical field of laser equipment, and more particularly to a high-power multilayer homogenizing laser system. Background Technology

[0002] With the continuous improvement of semiconductor laser performance and the reduction of cost, high-power laser technology is increasingly widely used in industrial production, scientific research and other fields. Achieving the synergy of "high power output" and "high beam quality" has become the core technical requirement. To meet the high power requirements, the industry generally adopts multi-laser module beam combining technology, but the existing beam combining scheme has significant technical bottlenecks.

[0003] After combining existing high-power semiconductor lasers, the beam is prone to multiple defects: Firstly, due to the spatial distribution differences of the output beams from each laser module, the combined beam exhibits significant gaps and uneven energy distribution, which simple single-stage homogenization cannot completely fill. Secondly, even after initial homogenization, the beam is easily affected by the optical characteristics of the lenses during subsequent amplification, leading to problems such as central region shrinkage and overall shape distortion, resulting in a renewed imbalance in beam uniformity. Furthermore, traditional homogenization schemes often employ a single homogenization mechanism (such as homogenization through microlens array segmentation), failing to optimize beam quality across all dimensions from "gap filling → energy equalization → distortion correction." The resulting output laser beam struggles to achieve high power density, high uniformity, and distortion-free characteristics, making it unsuitable for high-precision processing and other high-end applications. Therefore, developing a high-power laser system that can systematically solve the problems of beam combining gaps, energy unevenness, and amplification distortion through layered collaborative homogenization has become a pressing technical challenge in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a high-power multilayer homogenization laser system that can solve the above-mentioned problems existing in related technologies.

[0005] To achieve the above objectives, this application adopts the following technical solution: A high-power multilayer homogenizing laser system is provided, comprising: Multiple sets of laser source modules are used to output array beams, and the multiple sets of laser source modules are alternately inverted so that adjacent array beams are distributed in alternating positive and negative trapezoidal shapes. The combined homogenization module includes a mirror group, which is correspondingly disposed on the output side of each laser source module except the first group. It is used to redirect the corresponding array beam and splice it with the array beam of the previous group to form a uniform combined array light spot, thereby completing the first layer of homogenization. The microlens homogenization module includes an array of microlenses and a first lens arranged sequentially along the optical path. The array of microlenses divides the combined array light spot into multiple sub-beams, and the first lens causes the sub-beams to overlap and superimpose at their phase planes to complete the second layer of homogenization. The compensation, amplification, and homogenization module includes a compensation mirror disposed at the phase plane of the first lens and a second lens located behind it. The compensation mirror corrects the center contraction distortion after the beam is amplified, and the second lens amplifies and images the compensated beam to complete the third layer of homogenization, and finally outputs a uniform and distortion-free high-power laser spot.

[0006] Optionally, the laser source module includes at least one set of polarization beam combining sub-modules, each polarization beam combining sub-module including two laser units and a polarization beam combining mirror; One of the laser units is disposed on the transmission surface side of the polarization beam combiner, and its emitted laser is incident perpendicularly and exits through the polarization beam combiner; Another laser unit is disposed on the reflecting surface side of the polarization beam combiner, and its emitted laser is incident perpendicularly to the polarization beam combiner and reflected out by the polarization beam combiner at a 90° angle. After the two laser beams are transmitted and reflected by the polarization combiner, they are emitted from the output surface of the polarization combiner to form a polarization combined beam.

[0007] Optionally, each set of laser source modules includes two sets of polarization beam combining sub-modules and one set of wavelength beam combining modules, with the two sets of polarization beam combining modules corresponding to different laser wavelengths; The wavelength beam combiner module is disposed on the light-emitting side of the polarization beam combiner module, and includes a reflective lens and a wavelength beam combiner. The reflecting mirror is disposed in the light output direction of one of the sets of polarization beam combiners, and is used to receive and redirect the polarization beam combiner beam; The wavelength beam combiner is positioned in the light-emitting direction of another set of polarization beam combiner submodules. It is used to transmit the polarization beam combiner and reflect the polarization beam combiner that has been redirected by the reflector, so that the two polarization beam combiners overlap and are emitted.

[0008] Optionally, each of the reflector groups includes at least two reflectors, namely a first reflector and a second reflector; the first reflector is disposed in the output direction of the corresponding laser source module and is used to perform a first reorientation on the array beam; the second reflector is used to receive the beam reoriented by the first reflector and perform a second reorientation on it, so that the reoriented beam is aligned with the previous array beam.

[0009] Optionally, the shapes of the projections of the first and second reflectors along the incident direction of the array beam are both matched with the exit shape of the corresponding array beam.

[0010] Optionally, the array microlens includes a first array microlens and a second array microlens, which are arranged sequentially along the optical path to form a dual array mirror group.

[0011] Optionally, the first lens is a plano-convex lens, with the convex side of the plano-convex lens facing the array of microlenses and the planar side facing the compensation mirror.

[0012] Optionally, the surface of the compensation mirror is a freeform surface, and the curvature of the freeform surface is determined by reverse derivation based on the degree of distortion of the light spot after magnification by the second lens, in order to specifically compensate for the shrinkage distortion in the central region of the light spot after magnification by the second lens.

[0013] The beneficial effects of this application are as follows: This high-power multilayer homogenization laser system systematically solves the core pain points of beam gap, energy inhomogeneity, and amplification distortion in existing high-power laser beam combining technology through a three-layer collaborative homogenization design of trapezoidal complementary splicing → sub-beam splitting and overlapping → phase plane distortion compensation + amplification. It eliminates beam splicing gaps by alternately inverting the laser source module and splicing it with the mirror group, achieves energy depth equalization by microlens splitting and lens overlap, and avoids morphological distortion during amplification by targeted correction of the compensation mirror at the phase plane. The final output laser spot has high power density, high uniformity, and no deformation characteristics. Its overall structure is logically clear and the modules are compactly coordinated. It can achieve efficient homogenization without complex calibration and is adaptable to laser source modules with different power requirements and application scenarios with different amplification factors. It can stably meet the high-end scenarios with stringent requirements for spot quality, such as laser processing, material heat treatment, and large-area lithography, and has significant practicality and application expansion value. Attached Figure Description

[0014] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the high-power multilayer homogenizing laser system described in the embodiments of this application. Figure 2 This is a schematic diagram illustrating the structural principle of the laser source module and the combined homogenization module as described in the embodiments of this application. Figure 3 This is a schematic diagram of the structure of the combined homogenization module described in the embodiments of this application; Figure 4 for Figure 3 Cross-sectional views of sections AA, BB, and CC; Figure 5 This is a schematic diagram illustrating the structural principle of the microlens homogenization module and the compensation amplification homogenization module described in the embodiments of this application. Figure 6 This is a schematic diagram of the structure of the compensation mirror described in an embodiment of this application.

[0016] In the picture: 1. Laser source module; 11. Polarization beam combiner module; 111. Laser unit; 112. Polarization beam combiner mirror; 12. Wavelength beam combiner module; 121. Reflecting mirror; 122. Wavelength beam combiner mirror; 2. Combined homogenization module; 21. First reflecting mirror; 22. Second reflecting mirror; 3. Microlens homogenization module; 31. Array microlens; 311. First array microlens; 312. Second array microlens; 32. First lens; 4. Compensation amplification homogenization module; 41. Compensation mirror; 42. Second lens; 5. Array beam. Detailed Implementation

[0017] To make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0020] With the continuous improvement of semiconductor laser performance and the reduction of cost, high-power laser technology is increasingly widely used in industrial production, scientific research and other fields. Achieving the synergy of "high power output" and "high beam quality" has become the core technical requirement. To meet the high power requirements, the industry generally adopts multi-laser module beam combining technology, but the existing beam combining scheme has significant technical bottlenecks.

[0021] After combining existing high-power semiconductor lasers, the beam is prone to multiple defects: Firstly, due to the spatial distribution differences of the output beams from each laser module, the combined beam exhibits significant gaps and uneven energy distribution, which simple single-stage homogenization cannot completely fill. Secondly, even after initial homogenization, the beam is easily affected by the optical characteristics of the lenses during subsequent amplification, leading to problems such as central region shrinkage and overall shape distortion, resulting in a renewed imbalance in beam uniformity. Furthermore, traditional homogenization schemes often employ a single homogenization mechanism (such as homogenization through microlens array segmentation), failing to optimize beam quality across all dimensions from "gap filling → energy equalization → distortion correction." The resulting output laser beam struggles to achieve high power density, high uniformity, and distortion-free characteristics, making it unsuitable for high-precision processing and other high-end applications. Therefore, developing a high-power laser system that can systematically solve the problems of beam combining gaps, energy unevenness, and amplification distortion through layered collaborative homogenization has become a pressing technical challenge in this field.

[0022] To overcome the above technical problems, such as Figure 1 As shown, this application provides a high-power multilayer homogenizing laser system, including: Multiple sets of laser source modules 1 are used to output array beams 5, and the multiple sets of laser source modules 1 are alternately inverted so that adjacent array beams 5 are distributed in alternating positive and negative trapezoidal shapes. The combined homogenization module 2 includes a reflector group, which is correspondingly disposed on the output side of each of the laser source modules 1 except the first group. It is used to redirect the corresponding array beam 5 and splice it with the array beam 5 of the previous group to form a uniform combined array light spot and complete the first layer of homogenization. The microlens homogenization module 3 includes an array of microlenses 31 and a first lens 32 arranged sequentially along the optical path. The array of microlenses 31 divides the combined array light spot into multiple sub-beams, and the first lens 32 causes the sub-beams to overlap and superimpose at their phase planes to complete the second layer of homogenization. The compensation, amplification, and homogenization module 4 includes a compensation mirror 41 disposed at the phase plane of the first lens 32 and a second lens 42 located behind it. The compensation mirror 41 corrects the center contraction distortion after the beam is amplified, and the second lens 42 amplifies and images the compensated beam to complete the third layer of homogenization, and finally outputs a uniform and distortion-free high-power laser spot.

[0023] In the specific structure, the laser source module 1 serves as the core light-emitting and beam preprocessing unit. Each module contains multiple laser units 111 (preferably semiconductor laser units 111), and integrates a fast-axis optical collimation structure and a slow-axis optical collimation structure. Each laser unit 111 contains multiple stacked light emitters. The original laser emitted by the light emitters is collimated by both fast-axis and slow-axis collimation, and then... Figure 3 and Figure 4 Due to the imperfections of optical collimation and the influence of optical path difference, an array beam with trapezoidal characteristics is naturally formed (the area with a long optical path has a large divergence and a long length of the beam, while the area with a short optical path has a small divergence and a short length of the beam).

[0024] The reflector group serves as a beam spatial adjustment unit, correspondingly positioned on the output side of all laser source modules 1 except the first group (each non-first group of modules is equipped with one reflector group). Its core function is to eliminate spatial positional deviations in the output beams of different modules through reorientation adjustment, ensuring that the reoriented array beam 5 is aligned and connected with the previous beam, avoiding splicing gaps. The structure of the reflector group is adapted to the trapezoidal shape of the array beam 5, eliminating the need for complex optical compensation components; beam alignment can be achieved simply through reflection reorientation.

[0025] The combined homogenization module 2 in this solution actively utilizes and optimizes the "trapezoidal defect" caused by optical path difference, achieving a balance between uniform light spot and high power. The specific workflow is as follows: Beam generation and preprocessing: The laser units 111 in each laser source module 1 emit light synchronously. After fast-axis optical collimation and slow-axis optical collimation, the emitted laser forms an array beam 5 with natural trapezoidal characteristics (an inevitable result of optical path difference). Alternating trapezoidal layout: By using the "alternating inversion" setting of multiple sets of laser source modules 1, the array beams 5 output by adjacent modules present an alternating distribution of "positive trapezoidal-inverted trapezoidal", that is, the "trapezoidal notch" of the previous set of beams corresponds exactly to the "trapezoidal protrusion" of the next set of beams, providing a structural basis for complementary splicing. Reflector reorientation and alignment: For array beams 5 other than the first group, the orientation is reoriented by the reflector group on its output side, adjusting the original inverted trapezoidal / positive trapezoidal beams with spatial position deviation to be aligned with the previous group of beams, eliminating physical gaps; Seamless splicing output: After reorientation and alignment, multiple sets of alternating trapezoidal beams in a "positive-negative-positive" pattern are seamlessly spliced ​​through complementary gaps, ultimately forming a combined array of beams with uniform energy distribution and no gaps. At the same time, the stacking design of multiple modules ensures the high-power output of the laser.

[0026] Regarding the microlens homogenization module 3, it includes an array of microlenses 31 and a first lens 32 arranged sequentially along the optical path. The core function of the array of microlenses 31 is to split the beam, uniformly dividing the combined array light spot into multiple independent sub-beams, breaking the potential energy distribution differences in the local area of ​​the light spot. The array of microlenses 31 includes multiple microlens units of the same size and with uniform optical parameters. All microlens units are parallel and arranged in a matrix pattern on the same transparent optical substrate (the substrate material is usually high-transmittance optical glass or polymer to ensure lossless transmission of the beam). The unit arrangement density is adapted to the incident combined beam array to ensure that it can fully cover the incident beam cross section without any omissions. Each microlens unit is a miniature spherical lens or aspherical lens (preferably adapted to the beam convergence and splitting requirements). The radius of curvature and focal length of each unit are precisely designed so that it can not only perform preliminary convergence of the beam incident on its own region, but also enable the converged beam to exit at a preset divergence angle to form independent divergent sub-beams. The focal length and divergence angle parameters of all units are completely consistent to avoid the deviation of the propagation direction of the sub-beams due to differences in units. The first lens 32 is an imaging lens, whose core function is to converge and overlap. Through the principle of optical imaging, it directs and converges the dispersed sub-beams to its own phase plane, so that the energy of the sub-beams superimposes and fills each other, further neutralizing the uneven energy and forming a uniform light spot with balanced energy distribution.

[0027] The compensation, amplification, and homogenization module 4 includes a compensation mirror 41 disposed at the phase plane of the first lens 32 and a second lens 42 located at its rear end. The key structure of the compensation mirror 41 is positioned at the phase plane of the first lens 32, which is the reference plane for the second layer of homogenization. It can directly act on the high-quality homogenized light spot and specifically correct the "center shrinkage distortion" that is prone to occur during subsequent amplification. The second lens 42 serves as an amplification unit, and its core function is to optically amplify the homogenized light spot after compensation and correction, and finally output a large-size light spot that meets the application requirements, thus completing the dual tasks of distortion correction and amplification.

[0028] In summary, the core principle of this high-power multilayer homogenization laser system is to address the three major issues of beam gap, energy inhomogeneity, and amplification distortion through layered targeted processing, thereby achieving a synergistic output of high power, high uniformity, and distortion-free performance. The specific process is as follows: Special array beam 5 output: Multiple laser source modules 1 operate alternately in reverse, outputting an array beam 5 with alternating positive and negative trapezoidal shapes. The design logic of this distribution pattern is structural complementarity—the convex part of the positive trapezoid can precisely fill the concave part of the negative trapezoid, providing the inherent conditions for eliminating beam gaps.

[0029] The first layer of homogenization (splitting and gap filling): The reflector group of the combined homogenization module 2 redirects and adjusts the array beams 5 that are not in the first group, so that the originally alternately distributed positive / negative trapezoidal beams are precisely aligned and seamlessly spliced. For example, after the negative trapezoidal beams of the second group are redirected by the reflectors, their concave parts completely match the convex parts of the positive trapezoidal beams of the first group, forming a gapless and well-defined combined array light spot, solving the problem of poor uniformity caused by beam gaps.

[0030] The second layer of homogenization (energy equalization): The combined array light spot is incident on the microlens homogenization module 3. It is first divided into multiple independent sub-beams by the array microlens 31, dispersing the local energy difference into each sub-beam. Then, it is converged to its phase plane by the first lens 32. The sub-beams completely overlap and superimpose their energy at the phase plane. The original local energy difference is neutralized, forming a reference homogenized light spot with uniform energy distribution, thus completing the deep optimization for energy unevenness.

[0031] The third layer of homogenization (distortion correction + magnification): The compensation mirror 41 located at the phase plane of the first lens 32 directly acts on the reference homogenized spot. Through a preset structural design (such as a freeform surface), it specifically counteracts the central shrinkage distortion during magnification by the second lens 42, and corrects the shape of the central region of the spot in advance to avoid shrinkage and deformation after magnification. Subsequently, the second lens 42 magnifies and images the compensated spot, and finally outputs a high-power laser spot with no gaps, uniform energy, and no distortion, realizing the closed-loop optimization of the three-layer homogenization.

[0032] This high-power multilayer homogenization laser system systematically solves the core pain points of existing high-power laser beam combining technology, namely beam gap, energy inhomogeneity, and amplification distortion, through a three-layer collaborative homogenization design: trapezoidal complementary splicing, sub-beam splitting and overlapping, and phase plane distortion compensation and amplification. It eliminates beam splicing gaps by alternating inversion of the laser source module 1 and splicing with the mirror group, achieves energy depth equalization through microlens splitting and lens overlap, and avoids morphological distortion during amplification through targeted correction by the compensation mirror 41 at the phase plane. The final output laser spot possesses high power density, high uniformity, and deformation-free characteristics. Its overall structure is logically clear, with compact modules that achieve efficient homogenization without complex calibration. It is adaptable to laser source modules 1 with different power requirements and different amplification factors, stably meeting the stringent requirements of high-end applications such as laser processing, material heat treatment, and large-area lithography, demonstrating significant practicality and application expansion value.

[0033] In one embodiment, reference is made to Figure 2 The laser source module 1 includes at least one set of polarization beam combining sub-modules 11, and the polarization beam combining sub-module 11 includes two laser units 111 and a polarization beam combining mirror 112. One of the laser units 111 is disposed on the transmission surface side of the polarization combiner 112, and its emitted laser is incident perpendicularly and exits through the polarization combiner 112; Another laser unit 111 is disposed on the reflective surface side of the polarization combiner 112, and its emitted laser is incident perpendicularly on the polarization combiner 112 and reflected out by the polarization combiner 112 at a 90° angle. After the two laser beams are transmitted and reflected by the polarization combiner 112 and coincide, they are emitted from the light-emitting surface of the polarization combiner 112 to form a polarization combined beam.

[0034] The laser source module 1 includes at least one set of polarization beam combining sub-modules 11. Each sub-module consists of two laser units 111 and a polarization beam combiner 112, with a highly compatible layout and function. The two laser units 111 have clearly defined functions: one is located on the transmission surface side of the polarization beam combiner 112, and its emitted laser is perpendicularly incident on the transmission surface and directly exits through the beam combiner; the other is located on the reflection surface side of the polarization beam combiner 112, and its emitted laser is perpendicularly incident on the reflection surface, deflected by 90° by the beam combiner, and then exits. The polarization beam combiner 112 is the core beam combining component. Through the synergistic effect of "transmission + 90° reflection", it enables two laser beams from different directions to precisely overlap, and finally outputs a polarization combined beam from the same light-emitting surface of the beam combiner. This combined beam serves as the core output beam of the laser source module 1, and after collimation, it forms an array beam 5 with trapezoidal characteristics, adapting to the overall inverted complementary logic.

[0035] After polarization combining, the beam is collimated along the fast and slow axes, forming a trapezoidal array beam 5 due to the optical path difference. Combined with the alternating inversion of multiple laser source modules 1 and the reorientation and alignment of the reflector group, it finally participates in the complementary splicing of the positive and negative trapezoidal beams, achieving power superposition without affecting the overall homogenization effect.

[0036] This embodiment, through the design of the polarization beam combiner submodule 11, achieves power superposition at the laser unit 111 level without disrupting the core homogenization logic, significantly improving the output power density of a single laser source module 1 and providing stronger support for the high-power characteristics of the overall laser. Simultaneously, the "transmission + 90° reflection" design of the polarization beam combiner 112 ensures that the two laser beams are perpendicularly incident and precisely overlap, guaranteeing the consistency of the beam propagation direction after beam combining. This also allows for a compact and flexible submodule structure, achieving efficient beam combining without complex optical path calibration. Combined with subsequent trapezoidal complementarity and reflector reorientation, it enhances power while ensuring the uniformity and shape regularity of the combined beam spot. Furthermore, this beam combining method is highly adaptable, cost-controllable, and easy to implement in mass production, better meeting the stringent requirements of high-end industrial scenarios demanding both laser power and beam spot quality.

[0037] In one embodiment, when the polarization states of the two laser units 111 are the same, the polarization beam combining submodule 11 further includes a half-wave plate. The half-wave plate is disposed in the light output path of one of the laser units 111 to convert the polarization state of the corresponding laser, so that the two laser beams are adapted to the transmission and reflection requirements of the polarization beam combining mirror 112.

[0038] When two laser units 111 have the same polarization state, if they are directly incident on the polarization combiner 112, the polarization characteristics of the two laser beams cannot meet the combined beam requirements of "transmission + reflection" of the combiner, which will lead to beam combining failure or extremely low beam combining efficiency. After a half-wave plate is connected to the output optical path of one of the laser units 111, the polarization state of that laser beam is directionally converted so that the polarization state of the converted beam matches the polarization state of the other laser beam (satisfying the transmission and reflection conditions of the polarization combiner 112). The laser beam converted by the half-wave plate and the other unconverted laser beam are respectively incident on the polarization combiner 112 along the original path. Through the transmission and 90° reflection of the combiner, they are precisely overlapped to form a polarization combined beam with superimposed power. After being collimated by the fast axis and slow axis, a trapezoidal array beam 5 is formed, seamlessly connecting the alternating inversion of multiple modules and the homogenization logic of the reflector.

[0039] This embodiment effectively solves the beam combining problem caused by consistent polarization by adding a half-wave plate to the optical path of the laser unit 111 with the same polarization state. This significantly improves the selection flexibility of the polarization beam combining submodule 11 for the laser unit 111 (without requiring the laser unit 111 to have opposite polarization states), while ensuring the beam combining accuracy and power superposition efficiency of the two laser beams. The half-wave plate has a simple structure, small size, and controllable cost. After integration, it does not increase the complexity of the optical path or the difficulty of installation and debugging, nor does it affect the formation and complementary homogenization effect of the subsequent trapezoidal array beam 5. Under the premise of ensuring high power output and beam uniformity of the laser, it reduces the selection and matching cost of the laser unit 111.

[0040] In one embodiment, reference is made to Figure 2 Each laser source module 1 includes two sets of polarization beam combining sub-modules 11 and one set of wavelength beam combining modules 12, and the two sets of polarization beam combining modules 11 correspond to different laser wavelengths. The wavelength beam combiner module 12 is disposed on the light-emitting side of the polarization beam combiner module 11, and includes a reflector 121 and a wavelength beam combiner 122. The reflecting mirror 121 is disposed in the light output direction of one of the polarizing beam combiners 112, and is used to receive and redirect the polarizing beam. The wavelength beam combiner 122 is positioned in the light-emitting direction of another set of polarization beam combiner sub-modules 11. It is used to transmit the polarization beam combiner and reflect the polarization beam combiner that has been redirected by the reflector 121, so that the two polarization beam combiners overlap and are emitted.

[0041] Specifically, the two sets of polarization beam combining submodules 11 correspond to different laser wavelengths (for example, the first set of polarization beam combining submodules 11 outputs a combined beam with wavelength λ1, and the second set outputs a combined beam with wavelength λ2). The wavelength beam combining submodule 12 includes a reflecting mirror 121 and a wavelength beam combining mirror 122, which are disposed on the light-emitting side of the two sets of polarization beam combining submodules 11 to form a "direction-selective beam combining" layout; the reflecting mirror 121 is disposed in the light-emitting direction of one set of polarization beam combining mirrors 112, specifically to receive the polarization beam combining beam of that set and redirect it; the wavelength beam combining mirror 122 is disposed in the light-emitting direction of the other set of polarization beam combining submodules 11, and simultaneously undertakes the dual functions of "transmitting its own corresponding beam" and "reflecting the redirected beam".

[0042] The two sets of polarization beam combining submodules 11 operate independently, using a polarization beam combiner 112 to combine the beams from the two internal laser units 111, outputting two polarization beams of different wavelengths (λ1, λ2) but with superimposed power. A reflecting mirror 121 receives one of the polarization beams (e.g., λ1) and adjusts its propagation direction to match the propagation direction of the other polarization beam (e.g., λ2), satisfying the incident requirements of the wavelength beam combiner 122. The wavelength beam combiner 122 then combines the polarization beams along its corresponding path. (e.g., λ2) is transmitted, and at the same time, another polarized beam (e.g., λ1) that has been redirected by the reflecting mirror 121 is reflected. The wavelength selectivity is used to make the two beams of different wavelengths accurately overlap, forming a high-power beam with secondary superposition of power. The high-power beam after wavelength beam combining is then collimated by the fast axis and slow axis. Due to the optical path difference, a trapezoidal array beam 5 is formed. Subsequently, multiple sets of laser source modules 1 are alternately inverted and aligned with the reflecting mirror to participate in the complementary splicing of the positive and negative trapezoidal beams, ultimately achieving the dual goals of high power and high homogenization.

[0043] This embodiment employs a hierarchical beam combining design consisting of two sets of polarization beam combining submodules 11 and one set of wavelength beam combining submodules 12. This design achieves efficient beam combining of different wavelengths based on polarization beam combining, allowing for a secondary superposition of the output power of a single laser source module 1, significantly improving the overall power density of the laser. The selective transmission and reflection design of the wavelength beam combining mirror 122 ensures the accuracy and stability of beam combining of different wavelengths, and the beam combining process does not affect the formation and complementary homogenization effect of the subsequent trapezoidal array beam 5. Furthermore, this hierarchical beam combining structure has a compact layout and conventional component selection, achieving efficient beam combining without the need for a complex optical calibration system. While ensuring the uniformity and shape regularity of the combined beam spot, it further expands the upper limit of the laser's power and exhibits strong adaptability to different wavelength lasers, enhancing the application flexibility and engineering promotion value of the solution. It can better meet the stringent requirements of high-end industrial processing and laser pumping, which demand high power and high beam quality.

[0044] In one embodiment, each of the reflector groups includes at least two reflectors, namely a first reflector 21 and a second reflector 22; the first reflector 21 is disposed in the output direction of the corresponding laser source module 1 and is used to perform a first deflection of the array beam 5; the second reflector 22 is used to receive the beam deflected by the first reflector 21 and perform a second deflection on it, so that the deflected beam is aligned with the previous array beam 5; the deflection angle of the first reflector 21 and the second reflector 22 is 90°.

[0045] Each reflector group includes a first reflector 21 and a second reflector 22, which together form a cooperative reorientation unit to adapt to a single laser source module 1 other than the first group: the first reflector 21 is directly set in the output direction of the corresponding laser source module 1 and is adapted to the optical path of the trapezoidal array beam 5 output by the module. Its core function is to perform the first reorientation of the original array beam 5 and initially adjust the beam propagation path; the second reflector 22 is set at the edge of the previous array beam 5 and its shape matches the trapezoidal contour of the corresponding array beam 5. Its core function is to receive the beam reoriented by the first reflector 21 and achieve precise spatial calibration through the second reorientation to ensure that the reoriented beam is aligned and aligned with the previous array beam 5 in the same plane.

[0046] This embodiment uses a dual-mirror design with the first mirror 21 for initial reorientation and the second mirror 22 for precise calibration. This design further improves the alignment accuracy of the array beam 5, making the complementary effect of the positive and negative trapezoids more thorough. It effectively avoids the positional deviation that may exist with a single mirror reorientation and greatly optimizes the uniformity and regularity of the combined beam. Moreover, the dual-mirror design is simple and flexible in layout, requiring no complex optical calibration components, and is easy to install, debug, and mass-produce. By limiting the reversing angles of both the first reflector 21 and the second reflector 22 to 90°, the beam reversing path becomes more regular and controllable. This simplifies the installation and debugging process of the reflector group (eliminating the need for complex angle calibration) and ensures precise alignment between the array beam 5, which has undergone two 90° reversals, and the previous beam group. This allows for a more thorough complementary splicing of the positive and negative trapezoidal beams, further avoiding issues such as gaps in the beam pattern and uneven energy distribution. At the same time, the standardized 90° reversing design reduces the processing and adaptation difficulty of the reflector group, making the overall optical path layout more compact and regular. While ensuring high power output, it further improves the uniformity and shape regularity of the combined beam spot, and is easy to mass-produce and apply in engineering. It can more stably meet the stringent requirements of high-end industrial scenarios with both laser power and beam spot quality.

[0047] In one embodiment, the shapes of the projections of the first reflector 21 and the second reflector 22 along the incident direction of the array beam 5 are both matched with the exit shape of the corresponding array beam 5.

[0048] The shapes of the first reflector 21 and the second reflector 22 are designed based on the "emission shape of the array beam 5". When projected along the incident direction of the array beam 5, the projection contours of the two reflectors perfectly match the corresponding exit shape (trapezoidal) of the array beam 5. For example, the first reflector 21, which is adapted to the inverse trapezoidal array beam 5, has an inverse trapezoidal projection along the incident direction of the beam; the second reflector 22, which is used to receive the redirected beam, also has an incident direction projection that matches the exit shape of the inverse trapezoidal beam. This matching design ensures that the reflectors can completely cover the beam propagation path, avoiding beam edge overflow or optical path interference caused by reflector redundancy, while ensuring that the beam always fits the reflector contour during the redirection process, thus guaranteeing the accuracy of the propagation direction.

[0049] In its specific configuration, the second reflector 22 is precisely positioned to align with the edge of the preceding array beam 5, meaning its own edge directly connects to the edge of the previously emitted array beam 5, forming a seamless connection. This positioning allows the second reflector 22 to accurately receive beams redirected by the first reflector 21 (such as inverted trapezoidal beams). Simultaneously, through redirection, it directly guides the beam to the edge of the preceding array beam 5 (such as positive trapezoidal beams), ensuring that the redirected beam is perfectly aligned with the preceding beam at the edge, providing a physical positioning reference for the complementary splicing of the trapezoidal structure.

[0050] This embodiment matches the projection shapes of the first reflector 21 and the second reflector 22 along the incident direction of the array beam 5 with the corresponding exit shape of the array beam 5. This achieves full-aperture adaptation between the reflector and the beam, effectively avoiding energy loss caused by beam edge overflow. It also guides the beam to maintain the integrity of the trapezoidal contour during the two reversal processes, reducing directional deviation and stray reflections during reversal. This makes the complementary splicing of the positive and negative trapezoidal beams tighter and seamless, significantly improving the energy uniformity and shape regularity of the combined beam spot. At the same time, the shape matching design allows the reflector and the trapezoidal beam layout of the laser source module 1 to form a precise synergy, further optimizing the compactness and stability of the optical path. While ensuring high power output, it improves the energy utilization and operational reliability of the laser, and can more stably meet the stringent requirements of industrial processing, laser pumping, and other applications with demanding requirements for beam spot quality and power density.

[0051] In one embodiment, reference is made to Figure 5 The array microlens 31 includes a first array microlens 311 and a second array microlens 312, which are arranged sequentially along the optical path to form a double array mirror group.

[0052] In this embodiment, the array microlens 31 is configured as a first array microlens 311 and a second array microlens 312 arranged sequentially along the optical path to form a dual array mirror group. Compared with a single array microlens 31, it has a larger tolerance for the divergence angle of the incident light and can more flexibly adapt to parallel incident beams with different divergence characteristics, reducing the problem of uneven segmentation caused by the fluctuation of the beam divergence angle. At the same time, the dual array mirror group can perform secondary segmentation and regularization of the parallel incident beam, further dispersing the vertical gaps and energy unevenness defects that may exist in the original beam, making the segmented sub-beams more uniform and the propagation direction more regular, providing a higher quality foundation for the subsequent overlap and homogenization of the first lens 32, thereby making the energy distribution of the homogenized spot at the phase plane more uniform and the contour more regular.

[0053] In one embodiment, the focal length of the first lens 32 is matched with the segmentation density of the array microlenses 31 and the divergence angle of the sub-beams, such that the multiple sub-beams overlap on the phase plane of the first lens 32.

[0054] Specifically, the segmentation density of the array microlens 31 directly determines the number and spatial distribution of sub-beams. The higher the segmentation density, the more sub-beams there are and the smaller the spacing between them. The divergence angle of the sub-beams determines the degree of divergence during beam propagation. The larger the divergence angle, the easier it is for the sub-beams to deviate from the preset propagation path. These two parameters together determine the focusing capability required for sub-beam convergence. The focal length of the first lens 32 is the core parameter for adjusting the focusing capability. When the segmentation density of the array microlens 31 is high and the spacing between sub-beams is small, a first lens 32 with a shorter focal length can achieve dense convergence of sub-beams within a short optical path. When the divergence angle of the sub-beams is large, a first lens 32 with a longer focal length can avoid incomplete convergence caused by the sub-beams diverging too quickly. Through precise matching of focal length, segmentation density, and divergence angle, all sub-beams can be precisely superimposed and completely overlapped when they propagate to the phase plane of the first lens 32, forming a uniform light spot with a uniform energy distribution and regular contour. This provides a reference light spot of optimal quality for the distortion correction of the subsequent compensation mirror 41 and the magnification of the second lens 42.

[0055] This embodiment ensures that the sub-beams completely overlap and uniformly superimpose at the phase plane of the first lens 32 by matching the focal length of the first lens 32 with the segmentation density and divergence angle of the array microlenses 31. This effectively avoids problems such as sub-beam leakage and uneven overlap caused by parameter mismatch, and significantly improves the energy uniformity and contour regularity of the homogenized spot at the phase plane.

[0056] In one embodiment, the first lens 32 is a plano-convex lens, with the convex side of the plano-convex lens facing the array microlens 31 and the planar side facing the compensation mirror 41.

[0057] This embodiment defines the first lens 32 as a plano-convex lens and adopts an orientation layout with the convex side facing the array microlens 31 and the planar side facing the compensation mirror 41. This fully utilizes the efficient converging characteristics of the convex surface of the plano-convex lens, which can quickly gather the dispersed sub-beams after being divided by the array microlens 31, improve the accuracy and efficiency of the sub-beams converging towards the phase plane of the first lens 32, reduce energy loss and divergence during beam propagation, and ensure that the sub-beams completely overlap at the phase plane to form a uniform and regular homogenized light spot. Furthermore, the design of the planar side-facing compensation mirror 41 avoids secondary interference of the lens surface morphology on the homogenized light spot, making the contour and energy distribution of the reference light spot more stable, providing a more accurate basis for the distortion correction of the compensation mirror 41, and thus ensuring the distortion-free effect of the large light spot after subsequent magnification by the second lens 42.

[0058] In one embodiment, the surface of the compensation mirror 41 is a freeform surface, and the curvature of the freeform surface is determined by reverse derivation based on the degree of distortion of the light spot after magnification by the second lens 42, which is used to specifically compensate for the shrinkage distortion in the central region of the light spot after magnification by the second lens 42.

[0059] The core principle of this embodiment is a closed-loop logic of "distortion pattern analysis → reverse derivation design → targeted compensation", specifically: Distortion pattern acquisition: First, clarify the optical magnification characteristics of the second lens 42, and determine the distortion pattern of the magnified light spot through experiments or simulations. The core pattern is that the central region has the most significant shrinkage distortion, which gradually weakens towards the periphery. This is the premise of compensation design. Curvature inverse derivation: Based on the above distortion rules, the curvature of the free surface required for the compensation mirror 41 is calculated in reverse. For strong central contraction distortion, the corresponding high curvature compensation amount is derived to ensure that the surface can produce sufficient optical correction. For weak peripheral distortion, a relatively gentle curvature is matched to avoid overcompensation leading to new morphological deviations. Precise compensation is achieved by the compensation mirror 41 directly interacting with the homogenized light spot at the phase plane of the first lens 32. The curvature surface derived in reverse can provide strong targeted compensation for the central region of the light spot, thus offsetting the shrinkage effect when the second lens 42 is magnified in advance. At the same time, it also takes into account the slight correction of the surrounding areas, ultimately ensuring that the center of the magnified light spot does not shrink, the overall shape is regular, and the energy distribution is uniform.

[0060] This embodiment achieves targeted and precise compensation for light spot distortion by inversely deriving the curvature of the free-form surface of the compensation mirror 41 based on the degree of distortion of the light spot magnified by the second lens 42. In particular, it can completely solve the most prominent problem of central shrinkage distortion after magnification, so that the final output large light spot maintains both the regularity of the outline and does not destroy the energy uniformity. This reverse derivation design logic makes the compensation mirror 41 and the second lens 42 highly adaptable, and can flexibly cope with second lenses 42 with different magnifications and different distortion characteristics, greatly improving the application flexibility of the device.

[0061] In one embodiment, the compensation amount of the freeform surface gradually decreases from the center of the mirror to the four sides, which is adapted to the distortion gradient of the light spot magnified by the second lens 42.

[0062] This embodiment achieves precise step-by-step correction of light spot distortion by limiting the compensation amount of the freeform surface to gradually decrease from the center of the mirror to the four sides, and precisely matching the distortion gradient of the light spot magnified by the second lens 42, which is "strong distortion in the center and weak distortion in the periphery".

[0063] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other orientations or positional relationships are used only for ease of description and simplification of operation, 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 of this application. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0064] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0066] The technical principles of this application have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this application without inventive effort, and these embodiments will all fall within the scope of protection of this application.

Claims

1. A high-power multilayer homogenization laser system, characterized in that, include: Multiple sets of laser source modules (1) are used to output array beams (5), and the multiple sets of laser source modules (1) are alternately inverted so that adjacent array beams (5) are distributed in alternating positive and negative trapezoidal shapes; The combined homogenization module (2) includes a reflector group, which is correspondingly set on the output side of each laser source module (1) except the first group, and is used to redirect the corresponding array beam (5) and splice it with the array beam (5) of the previous group to form a uniform combined array light spot, thus completing the first layer of homogenization. The microlens homogenization module (3) includes an array of microlenses (31) and a first lens (32) arranged sequentially along the optical path. The array of microlenses (31) divides the combined array light spot into multiple sub-beams, and the first lens (32) makes the sub-beams overlap and superimpose at their phase planes to complete the second layer of homogenization. The compensation amplification homogenization module (4) includes a compensation mirror (41) disposed at the phase plane of the first lens (32) and a second lens (42) located behind it. The compensation mirror (41) corrects the center contraction distortion after the beam is amplified, and the second lens (42) amplifies and images the compensated beam to complete the third layer of homogenization and finally outputs a uniform and undistorted high-power laser spot.

2. The high-power multilayer homogenizing laser system according to claim 1, characterized in that, The laser source module (1) includes at least one set of polarization beam combining sub-modules (11), and the polarization beam combining sub-modules (11) include two laser units (111) and a polarization beam combining mirror (112); One of the laser units (111) is disposed on the transmission surface side of the polarization beam combiner (112), and its emitted laser is incident perpendicularly and exits through the polarization beam combiner (112); Another laser unit (111) is disposed on the reflective surface side of the polarization beam combiner (112), and its emitted laser is incident perpendicularly on the polarization beam combiner (112) and deflected out by 90° via the polarization beam combiner (112); After the two laser beams are transmitted and reflected by the polarization combiner (112) and then emitted from the light-emitting surface of the polarization combiner (112), they form a polarization combined beam.

3. The high-power multilayer homogenizing laser system according to claim 2, characterized in that, Each set of laser source modules (1) includes two sets of polarization beam combining sub-modules (11) and one set of wavelength beam combining sub-modules (12), and the two sets of polarization beam combining sub-modules (11) correspond to different laser wavelengths; The wavelength beam combiner (12) is disposed on the light-emitting side of the polarization beam combiner (11), and includes a reflector (121) and a wavelength beam combiner (122); The reflecting mirror (121) is disposed in the light output direction of one of the polarizing beam combiners (112) for receiving and redirecting the polarizing beam combiner. The wavelength beam combiner (122) is positioned in the light-emitting direction of another set of polarization beam combiner sub-modules (11) to transmit the set of polarization beam combiners and reflect the polarization beam combiners that have been redirected by the reflector (121), so that the two polarization beam combiners overlap and are emitted.

4. The high-power multilayer homogenizing laser system according to claim 1, characterized in that, Each of the aforementioned reflector groups includes at least two reflectors, namely a first reflector (21) and a second reflector (22); the first reflector (21) is set in the output direction of the corresponding laser source module (1) and is used to perform a first reorientation on the array beam (5); the second reflector (22) is used to receive the beam reoriented by the first reflector (21) and perform a second reorientation on it, so that the reoriented beam is aligned with the previous array beam (5).

5. The high-power multilayer homogenizing laser system according to claim 4, characterized in that, The shapes of the projections of the first reflector (21) and the second reflector (22) along the incident direction of the array beam (5) are both matched with the exit shape of the corresponding array beam (5).

6. The high-power multilayer homogenizing laser system according to claim 1, characterized in that, The array microlens (31) includes a first array microlens (311) and a second array microlens (312), which are arranged sequentially along the optical path to form a double array lens group.

7. The high-power multilayer homogenizing laser system according to claim 1, characterized in that, The first lens (32) is a plano-convex lens, with the convex side facing the array microlens (31) and the planar side facing the compensating mirror (41).

8. The high-power multilayer homogenizing laser system according to claim 1, characterized in that, The surface of the compensation mirror (41) is a freeform surface. The curvature of the freeform surface is determined by reverse derivation based on the degree of distortion of the light spot after magnification by the second lens (42), and is used to specifically compensate for the shrinkage distortion in the central region of the light spot after magnification by the second lens (42).

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