A laser amplification element, laser amplification assembly and laser generator

Abstract

This invention discloses a laser amplification element, a laser amplification assembly, and a laser generator. The laser amplification element includes multiple layers of slab crystals and multiple layers of heat sinks. The multiple heat sinks are stacked sequentially, and the multiple slab crystals are sandwiched between the multiple heat sinks, with at most one slab crystal between any two adjacent heat sinks. This arrangement of the multiple slab crystals in a stacked manner, with heat sinks on both sides of each slab crystal layer, allows the heat generated by each slab crystal layer to be promptly dissipated by the heat sinks. Simultaneously, the heat sinks between adjacent slab crystal layers also provide a degree of thermal insulation. Multiple slab crystals operate synchronously, enabling step-by-step power amplification of seed light. Alternatively, when the seed light is split into multiple beams, each slab crystal layer can independently amplify one beam, thereby achieving high-power laser output.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and particularly relates to a laser amplification element, laser amplification assembly and laser generator with high power characteristics and stable operation. Background Technology

[0002] With the increasing demand for high-power ultrafast lasers (femtosecond / picosecond) in advanced micro / nano manufacturing, extreme ultraviolet (EUV) light source driving, and extreme scientific devices, solid-state laser amplification technology is moving towards kilowatt-level average power and megawatt-level peak power. In typical ultrafast laser high-power amplification chains, since the seed light output from the front-end oscillator is usually only on the order of milliwatts (mW), it cannot directly bring the main amplifier to a saturated extraction state. Therefore, the industry generally adopts a cascaded architecture of "pre-amplification + main amplification".

[0003] Specifically, the pre-amplification stage typically employs a rod laser amplifier, utilizing its high small-signal gain in the low-power range to boost the mW-level seed light to the watt (W) or tens of watts level; the main amplification stage then uses a slab crystal for amplification. Slab crystals are typically on the order of 1 millimeter in thickness, possessing the physical characteristics of one-dimensional large-area forced heat dissipation. Combined with existing microchannel water-cooled heat sink technology, they can withstand kilowatt-level pump heat loads and effectively suppress thermal lensing effects, thereby achieving laser output with both high power and high beam quality.

[0004] However, as industrial applications place increasingly stringent demands on the overall size, weight, power consumption (SWaP), environmental immunity, and peak power limits of lasers, the existing "Rod + monolithic slab crystal" cascade amplification technology has revealed the following three major systemic technical bottlenecks: 1. Two-dimensional planar topology leads to insufficient mechanical stiffness and spatial redundancy: Existing systems typically deploy the pre-amplification optical path, beam shaping optical path, and single-slab crystal multi-way folding (Zig-zag) main amplification optical path in a two-dimensional plane on a large vibration-resistant optical platform. This layout occupies a large area and has long optical cantilever, resulting in a low first-order mechanical resonant frequency of the system. It is extremely sensitive to high-frequency micro-vibrations of machine tools and ambient temperature gradients, and is prone to optical axis drift.

[0005] 2. Low utilization of the spatial geometry of pump source devices: High-power pump source devices for slab crystal master amplification are typically semiconductor light-emitting diode (LD) stacks, whose emitted beams have a large physical height and divergence angle along the fast axis. Existing technologies mostly rely on complex aspherical cylindrical lens groups to significantly compress this wide beam spatially to couple it into a single horizontal slab crystal. This not only increases the manufacturing cost of aspherical lenses and easily introduces nonlinear wavefront aberrations, but also fails to fully utilize the multi-channel parallel emission characteristics of LD stacks (laser diode stacks) in the vertical dimension.

[0006] 3. Limited power extraction from a single slab crystal and the dramatic increase in volume caused by horizontal expansion: There are physical limits to the pump heat load and nonlinear B integral that a single slab crystal can bear.

[0007] To further improve the overall output power, the conventional approach is to horizontally add a single slab crystal equipped with an independent pump light source device on a two-dimensional plane, resulting in a linear increase in system size and cost. Due to the interlayer thermal interference effect under high heat flux density, it is difficult for the industry to achieve high-density vertical aggregation of multiple gain media and single-source shared pumping. Summary of the Invention

[0008] In order to solve the above-mentioned technical problems, one of the objectives of the present invention is to provide a laser amplification element with a compact structure, controllable heat generation, and good durability.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A laser amplification element includes a multilayer slab crystal and a multilayer heat sink layer, wherein the multilayer heat sink layer is stacked sequentially, the multilayer slab crystal is sandwiched between the multilayer heat sink layer, and at most one layer of the slab crystal is present between any two adjacent heat sink layers.

[0010] The beneficial effects of the above-mentioned technical solution of the present invention are as follows: the multilayer slab crystals are arranged in a stacked manner, and heat sink layers are provided on both sides of each layer of slab crystals. This allows the heat generated by each layer of slab crystals to be carried away by the heat sink layers in a timely manner. At the same time, the heat sink layers between adjacent layers of slab crystals can also play a certain role in thermal isolation. The multiple slab crystals operate synchronously, which can amplify the power of the seed light step by step. Alternatively, when the seed light is divided into multiple beams, each layer of slab crystals can independently amplify the power of one beam of seed light, thereby achieving high-power laser output.

[0011] Based on the above technical solution, this solution can be further improved as follows: Furthermore, it also includes a heat insulation layer, wherein the lath crystal is provided with n layers, the heat sink layer is provided with 2n layers, and the heat insulation layer is provided with n-1 layers. Each layer of lath crystal corresponds to two layers of the heat sink layer, and each layer of lath crystal is sandwiched between the corresponding two layers of the heat sink layer to form a lath crystal component. Multiple lath crystal components are stacked sequentially, and a heat insulation layer is sandwiched between two adjacent lath crystal components, wherein n is a positive integer and n≥2.

[0012] The beneficial effect of the above-mentioned further technical solution is that each layer of the slab crystal has a better heat dissipation function, and there is also a heat insulation layer between two adjacent slab crystals, which can prevent heat accumulation in the slab crystal located in the middle.

[0013] Furthermore, the heat sink layer is a microchannel liquid cooling plate.

[0014] The beneficial effect of the above-mentioned further technical solution is that it has a good cooling effect.

[0015] To address the aforementioned technical problems, a second objective of this invention is to provide a laser amplification element that is compact in structure, has controllable heat generation, and is durable.

[0016] To achieve the above objectives, the technical solution of the present invention is as follows: a laser amplification assembly, comprising a pump light source device and a laser amplification element as described above, wherein the pump light source device is used to supply pump light to the laser amplification element, so that the laser amplification element amplifies the received seed light and outputs it.

[0017] The beneficial effects of the above-mentioned technical solution of the present invention are as follows: pump light can be supplied to multiple laser amplification elements simultaneously by one pump light source device, which makes the structure of the entire laser amplification assembly more compact, and multiple slab crystals are stacked inside the laser amplification element, which enables the entire laser amplification element to output a high-power laser beam.

[0018] Based on the above technical solution, this solution can be further improved as follows: Furthermore, it also includes a shaping and homogenizing optical path, a pump mirror, two pump shaping mirror groups, and two cavity mirror groups. The laser amplification element is disposed between the two cavity mirror groups. The two pump shaping mirror groups are disposed on the side of the two cavity mirror groups that are far apart from each other. The shaping and homogenizing optical path and the pump mirror are disposed on the side of the two pump shaping mirror groups that are far apart from each other. The pump light source device is disposed on the side of the shaping and homogenizing optical path that is far away from the laser amplification element. The pump light source device is used to emit pump light, which is sequentially directed to the laser amplification element through the shaping and homogenizing optical path, the pump shaping mirror group, and the cavity mirror group adjacent to it. The pump light emitted by the laser amplification element is reflected by the pump mirror and the cavity mirror group and the pump shaping mirror group on the corresponding side and is reused by the laser amplification element.

[0019] The beneficial effect of the above-mentioned further technical solution is that the pump light energy emitted by the pump light source device is fully utilized by the laser amplification element, thereby reducing energy loss.

[0020] Furthermore, it also includes two beam-splitter groups, with one beam-splitter group located between the pump shaping mirror group and the cavity mirror group, which are close to each other. The beam-splitter group closer to the pump light source device is used to split the pump light into multiple beams and direct them to multiple slab crystals respectively. The pump light emitted from the multiple slab crystals is then bundled by the other beam-splitter group and directed to the pump reflector, and split into multiple beams during reflection to direct them to multiple slab crystals respectively.

[0021] The beneficial effect of the above-mentioned further technical solution is that the pump light emitted by the pump light source device is divided into multiple beams by the beam splitter group close to it, and each beam corresponds to a multiple slab crystal. This allows each slab crystal to have a beam of pump light directed towards it, and the pump light emitted from each slab crystal can be combined by another beam splitter group, and finally fed back and split back to each of the slab crystals. This allows the pump light energy emitted by the pump light source device to be fully utilized by the laser amplification element, and the energy obtained by each slab crystal is equivalent.

[0022] Furthermore, the cavity mirror assembly includes two dichroic mirrors and two cavity mirrors. The dichroic mirrors transmit the pump light, and the dichroic mirrors and cavity mirrors reflect the seed light. The two dichroic mirrors are located between the two cavity mirrors, and the two dichroic mirrors and the two cavity mirrors are distributed at intervals along the stacking direction of the multilayer lath crystal.

[0023] The beneficial effect of the above-mentioned further technical solution is that the pump light can be directed to each of the slab crystals through the dichroic mirror, and the slab crystals can be excited to amplify the power of the seed light.

[0024] Furthermore, the pump light source device integrates multiple semiconductor bars.

[0025] The beneficial effect of the above-mentioned further technical solution is that it makes the pump light source device small in size and can output high-power pump light to meet the energy requirements of high-power laser.

[0026] The third objective of this invention is to provide a laser generator with a simple structure that can achieve high-power laser beam output.

[0027] To achieve the above objectives, the technical solution of the present invention is as follows: a laser generator, comprising a seed light source device, an output optical path device, and a laser amplification assembly as described above, wherein the seed light source device is used to supply seed light to the laser amplification assembly, and the seed light is amplified by the laser amplification assembly and then emitted by the output optical path device.

[0028] The beneficial effect of the above-mentioned further technical solution is that the seed light source device emits seed light to the laser amplification assembly, and the laser amplification assembly amplifies the seed light under the action of pump light to obtain a high-power laser beam, which is finally processed and output by the output optical path device.

[0029] Furthermore, the output optical path includes an isolator, an output shaping lens group, and a spatial filter device arranged in sequence. The laser beam output by the laser amplification assembly passes through the isolator, the output shaping lens group, and the spatial filter device in sequence before being output.

[0030] The beneficial effect of the above-mentioned further technical solution is that it enables the laser beam to be shaped and stray light filtered out before being output.

[0031] Furthermore, it also includes a substrate, on which the laser amplification assembly, seed light source device and output optical path device are integrated, and at least a portion of the laser amplification assembly, seed light source device and output optical path device are disposed on the front side of the substrate, while the remaining portion is disposed on the back side of the substrate.

[0032] The beneficial effect of the above-mentioned further technical solution is that it makes the entire laser generator more compact. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the laser amplification element when the slab crystal is provided with three pieces in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the laser amplification element when two slab crystals are provided in an embodiment of the present invention; Figure 3 This is a simplified structural diagram of the laser amplification assembly described in an embodiment of the present invention; Figure 4 This is a schematic diagram of the optical path of the laser amplification assembly described in an embodiment of the present invention; Figure 5 This is a simplified structural diagram of the laser generator described in an embodiment of the present invention; Figure 6 This is a schematic diagram of the optical path of the laser amplification assembly when two slab crystals are connected in series in an embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the principle of two slab crystals connected in series in an embodiment of the present invention; Figure 8 This is a schematic diagram of the optical path of the laser amplification assembly when two slab crystals are connected in parallel in an embodiment of the present invention; Figure 9 This is a schematic diagram illustrating the principle of two slab crystals connected in parallel in an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of the laser generator described in an embodiment of the present invention.

[0034] In the diagram: 1. Laser amplification assembly; 11. Laser amplification element; 111. Slab crystal; 112. Heat sink layer; 113. Heat insulation layer; 12. Pump source device; 121. Semiconductor bar; 13. Shaping and homogenizing optical path; 14. Pump mirror; 15. Pump shaping mirror assembly; 15a. First pump shaping mirror assembly; 15b. Second pump shaping mirror assembly; 16. Cavity mirror assembly; 16a. First cavity mirror assembly; 16b. Second cavity mirror. Group; 161, Dichroic mirror; 162, Cavity mirror; 163, Cascaded shaping mirror; 164, Cascaded polarization modulator; 17, Beam splitter group; 17a, First beam splitter group; 17b, Second beam splitter group; 171, Knife-edge prism reflector; 172, Plane reflector; 2, Seed light source device; 3, Outgoing optical path device; 31, Isolator; 32, Output shaping lens group; 33, Spatial filter device; 4, Substrate; 41, Through-hole. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0038] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0039] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0040] like Figure 1 and Figure 2 As shown, this embodiment provides a laser amplification element 11, including multiple layers of slab crystals 111 and multiple layers of heat sinks 112. The multiple layers of heat sinks 112 are stacked sequentially, and the multiple layers of slab crystals 111 are sandwiched between the multiple layers of heat sinks 112, with at most one layer of slab crystals 111 between any two adjacent layers of heat sinks 112. This arrangement of multiple layers of slab crystals 111 in a stacked manner, with heat sinks 112 on both sides of each layer of slab crystals 111, allows the heat generated by each layer of slab crystals 111 to be promptly dissipated by the heat sinks 112. Simultaneously, the heat sinks 112 between adjacent layers of slab crystals 111 also provide a certain degree of thermal insulation. The multiple slab crystals 111 operate synchronously, enabling step-by-step power amplification of the seed light. Alternatively, when the seed light is divided into multiple beams, each layer of slab crystals 111 can independently amplify the power of one beam of seed light, thereby achieving high-power laser output.

[0041] In this embodiment, the multiple lath crystals 111 amplify the seed light in two ways, as follows: Series configuration: In this case, the seed light is sequentially amplified in power by multiple lath crystals 111, ultimately resulting in a laser with amplified power (such as...). Figure 7 (As shown).

[0042] Parallel configuration: In this case, the seed light is first split into multiple beams, and each beam corresponds one-to-one with one of the lath crystals 111. Each lath crystal 111 independently amplifies the power of its corresponding seed light, resulting in multiple beams of amplified seed light. These amplified seed light beams are then combined to obtain the amplified laser beam (e.g.,...). Figure 9 (As shown).

[0043] like Figure 1 and Figure 2 As shown, in this embodiment, the laser amplification element 11 further includes a heat insulation layer 113. The slab crystal 111 has n layers, the heat sink layer 112 has 2n layers, and the heat insulation layer 113 has n-1 layers. Each layer of the slab crystal 111 corresponds to two layers of the heat sink layer 112, and each layer of the slab crystal 111 is sandwiched between the corresponding two layers of the heat sink layer 112 to form a slab crystal component. Multiple slab crystal components are stacked sequentially, with a heat insulation layer 113 sandwiched between adjacent slab crystal components. Here, n is a positive integer, and n≥2. This ensures that each layer of the slab crystal 111 has good heat dissipation capabilities, and the presence of a heat insulation layer 113 between adjacent slab crystals 111 prevents heat accumulation in the slab crystal 111 located in the middle.

[0044] In this embodiment, the heat sink layer 112 is a microchannel liquid cooling plate, which has a good cooling effect and can withstand kilowatt-level pump heat load and effectively suppress thermal lensing effect. This is beneficial for achieving laser output with both high power and high beam quality.

[0045] In this embodiment, the heat insulation layer 113 can be a ceramic heat insulation board, a polymer aerogel heat insulation board, a CVD diamond board (chemical vapor deposition diamond board), etc.

[0046] The feature of this embodiment is that the multiple layers of slab crystals 111 are arranged in a stacked manner, which makes the entire laser amplification element 11 small and compact. In this embodiment, the heat sink layer 112 and the heat insulation layer 113 can achieve interlayer thermal decoupling between the multiple layers of slab crystals 111, thereby achieving ultra-compact, highly stable, and high-power laser output.

[0047] like Figure 3As shown, this embodiment also provides a laser amplification assembly 1, including a pump source device 12 and a laser amplification element 11 as described above. The pump source device 12 supplies pump light to the laser amplification element 11, so that the laser amplification element 11 amplifies the received seed light and outputs it. In this way, one pump source device 12 can simultaneously supply pump light to multiple laser amplification elements 11, making the structure of the entire laser amplification assembly 1 more compact. Furthermore, multiple slab crystals 111 are stacked inside the laser amplification element 11, enabling the entire laser amplification element 11 to output a high-power laser beam.

[0048] like Figure 4 As shown, the laser amplification assembly 1 in this embodiment further includes a shaping and homogenizing optical path 13, a pump mirror 14, two pump shaping mirror groups 15, and two cavity mirror groups 16. The shaping and homogenizing optical path 13, the pump source device 12, the laser amplification element 11, the pump mirror 14, the two pump shaping mirror groups 15, and the two cavity mirror groups 16 are linearly distributed. Specifically, the laser amplification element 11 is disposed between the two cavity mirror groups 16, and the two pump shaping mirror groups 15 are disposed on the side of the two cavity mirror groups 16 that are far apart from each other. The shaping and homogenizing optical path 13 and the pump mirror... The pump reflector 14 is positioned on one side of the two pump shaping mirror groups 15 that are far apart from each other. The pump light source device 12 is positioned on the side of the shaping and homogenizing optical path 13 that is far away from the laser amplification element 11. The pump light source device 12 emits pump light, which is sequentially directed through the shaping and homogenizing optical path 13, the pump shaping mirror group 15, and the cavity mirror group 16 adjacent to it, and then directed towards the laser amplification element 11. The pump light emitted by the laser amplification element 11 is reflected by the pump reflector 14 and the cavity mirror group 16 and the pump shaping mirror group 15 on the corresponding side, and then reused by the laser amplification element 11. In this way, the pump light energy emitted by the pump light source device 12 is fully utilized by the laser amplification element 11, thereby reducing energy loss.

[0049] In this embodiment, the shaping and homogenizing optical path 13, the pump reflector 14, the two pump shaping mirror groups 15, and the two cavity mirror groups 16 can all be regarded as existing mature technologies, and will not be described in detail here.

[0050] like Figure 6 and Figure 8As shown, the laser amplification assembly 1 in this embodiment further includes two beam splitter groups 17. A beam splitter group 17 is provided between the pump shaping mirror group 15 and the cavity mirror group 16, which are close to each other. The beam splitter group 17 close to the pump light source device 12 is used to split the pump light into multiple beams and direct them to multiple slab crystals 111 respectively. The pump light emitted from the multiple slab crystals 111 is combined by the other beam splitter group 17 and directed to the pump reflector 14. During the reflection, it is split into beams and directed to multiple slab crystals 111 respectively. This allows the pump light emitted from the pump source device 12 to be split into multiple beams by the beam splitter group 17 located nearby, and each beam corresponds to one of the multiple slab crystals 111. This ensures that each slab crystal 111 has a beam of pump light directed towards it, and the pump light emitted from each slab crystal 111 can be combined by another beam splitter group 17, and finally fed back and split back to each of the slab crystals 111. This ensures that the pump light emitted from the pump source device 12 is fully utilized by the laser amplification element 11, and that each slab crystal 111 receives roughly the same amount of energy.

[0051] like Figure 4 , Figure 6 and Figure 8 As shown, in this embodiment, the two pump shaping mirror groups 15 are respectively the first pump shaping mirror group 15a and the second pump shaping mirror group 15b; the two cavity mirror groups 16 are respectively the first cavity mirror group 16a and the second cavity mirror group 16b; and the two beam splitter groups 17 are respectively the first beam splitter group 17a and the second beam splitter group 17b. The first pump shaping mirror group 15a and the first cavity mirror group 16a are located between the pump light source device 12 and the laser amplification element 11; the second pump shaping mirror group 15b and the second cavity mirror group 16b are located between the pump reflector 14 and the laser amplification element 11; the first beam splitter group 17a is located between the first pump shaping mirror group 15a and the laser amplification element 11; and the second beam splitter group 17b is located between the second pump shaping mirror group 15b and the laser amplification element 11.

[0052] In this embodiment of the laser amplification element 11, the beam splitter group 17 includes a prism reflector 171 and two plane reflectors 172, with the two plane reflectors 172 located on both sides of the prism reflector 171. The prism reflector 171 is used to combine or split the pump light. In the first beam splitter group 17a, the prism reflector 171 splits the pump light into two parallel pump lights by the two plane reflectors 172. The second beam splitter group 17b is similar, first combining the two scattered pump lights, then reflecting them back and splitting them again.

[0053] like Figures 6-9As shown in this embodiment, two slab crystals 111 can be provided. In this case, the heat sink layer 112 has four layers, and the heat insulation layer 113 has one layer. In this embodiment, the pump light is split into two beams by the first beam splitter group 17a and directed towards the two slab crystals 111 respectively. Similarly, the pump light emitted from the two slab crystals 111 is first combined by the second beam splitter group 17b and then split.

[0054] like Figure 6 and Figure 8 As shown, in this embodiment, the cavity mirror assembly 16 includes two dichroic mirrors 161 and two cavity mirrors 162. The dichroic mirrors 161 transmit the pump light, while the dichroic mirrors 161 and cavity mirrors 162 reflect the seed light. The two dichroic mirrors 161 are located between the two cavity mirrors 162, and the two dichroic mirrors 161 and the two cavity mirrors 162 are spaced apart along the stacking direction of the multilayer lath crystals 111. This allows the pump light to pass through the dichroic mirrors 161 to each lath crystal 111, thereby exciting the lath crystals 111 to amplify the power of the seed light.

[0055] In this embodiment, the cavity mirror group 16 is configured to guide the seed light at the watt level to undergo multi-pass zig-zag main amplification within multiple slab crystals 111 at a grazing angle that satisfies the total internal reflection condition, and finally output as a laser with amplified power.

[0056] like Figure 3 As shown, the pump light source device 12 in this embodiment integrates multiple semiconductor bars 121. This makes the pump light source device 12 compact in size and able to output high-power pump light to meet the energy requirements of high-power lasers.

[0057] Specifically, such as Figure 3 As shown, the semiconductor bars 121 are distributed in multiple layers, with each layer having multiple semiconductor bars 121 arranged in an array. The multiple semiconductor bars 121 are stacked vertically along the fast axis, thus configuring the output to produce a wide-amplitude pump light with fast axis broadening characteristics (and the entire pump light source device 12 is compact in size). Eight semiconductor bars 121 can be provided, arranged in four layers, with two semiconductor bars 121 in each layer.

[0058] like Figure 5As shown, this embodiment also provides a laser generator, including a seed light source device 2, an output optical path device 3, and a laser amplification assembly 1 as described above. The seed light source device 2 supplies seed light to the laser amplification assembly 1. The seed light is amplified by the laser amplification assembly 1 and then emitted by the output optical path device 3. This allows the seed light source device 2 to emit seed light into the laser amplification assembly 1, and the laser amplification assembly 1, under the action of pump light, amplifies the seed light to obtain a high-power laser beam. Finally, the output optical path device 3 processes and outputs the laser beam.

[0059] In this embodiment, the seed light source device 2 has a rod-shaped pre-amplified optical path, which is configured to generate milliwatt (mW) level ultrafast seed light, and utilizes its own small signal gain characteristics to prevent the ultrafast seed light from being large watt (W) level seed light, and then delivers it to the laser amplification assembly 1.

[0060] like Figure 5 As shown, the output optical path component 3 in this embodiment includes an isolator 31, an output shaping lens group 32, and a spatial filter component 33 arranged sequentially. The laser beam output from the laser amplification assembly 1 passes through the isolator 31, the output shaping lens group 32, and the spatial filter component 33 sequentially before being output. This ensures that the laser beam is shaped and stray light is filtered out before being output. In this embodiment, the spatial filter component 33 can be a spatial filtering lens group, which is mainly configured to filter out high-frequency spatial noise and amplify spontaneous emission (ASE) during the power amplification process of the seed light.

[0061] like Figure 10 As shown, the laser generator in this embodiment further includes a substrate 4. The laser amplification assembly 1, the seed light source device 2, and the output optical path device 3 are integrated on the substrate 4. At least a portion of the laser amplification assembly 1, the seed light source device 2, and the output optical path device 3 are disposed on the front side of the substrate 4, while the remaining portion is disposed on the back side of the substrate 4. This makes the overall size of the laser generator more compact. In this embodiment, the substrate 4 also has light-passing holes 41 (the number and position of the light-passing holes 41 in this embodiment are determined according to specific needs), so that the seed light, pump light, or amplified laser light can pass through the substrate 4.

[0062] In this embodiment, the substrate 4 can be precision machined from Invar 36 steel with a low coefficient of thermal expansion, and microfluidic channels can be integrated inside for liquid cooling.

[0063] In this embodiment, the laser amplification element 11 has two slab crystals 111, and the two slab crystals 111 amplify the seed light in series (e.g., Figure 6 and Figure 7As shown), the seed light (10W after pre-amplification) is first amplified by one of the lath crystals 111, and then amplified a second time by another lath crystal 111, resulting in a laser beam with amplified power (kilowatt level) and high beam quality (M2 < 1.2). In this case, the second cavity mirror group 16b also includes a cascaded shaping mirror 163 and a cascaded polarization modulator 164, which are used for beam shaping and polarization optimization of the seed light before the second main amplification. However, if the two lath crystals 111 amplify the seed light in parallel (e.g., ...), the seed light is amplified by two lath crystals 111 in parallel (e.g., ...). Figure 8 and Figure 9 As shown), the seed light is first split into two beams and supplied to the two lath crystals 111 for amplification. The two amplified laser beams are then combined to obtain a highly stable short-pulse laser beam.

[0064] It should be noted that in the above embodiments, pump light, seed light, laser, etc., all exist in the optical path in the form of light beams [wherein, Figures 6-9 In the above embodiments, “A” represents pump light; “B” represents seed light; and “C” represents laser light (i.e., amplified laser light). Any parts not described in detail in the above embodiments can be regarded as prior art and will not be elaborated here.

[0065] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A laser amplification element, characterized in that, It includes a multilayer lath crystal (111) and a multilayer heat sink layer (112), the multilayer heat sink layer (112) is stacked in sequence, the multilayer lath crystal (111) is sandwiched between the multilayer heat sink layer (112), and there is at most one layer of lath crystal (111) between any two adjacent heat sink layers (112).

2. The laser amplification element according to claim 1, characterized in that, It also includes a heat insulation layer (113), wherein the lath crystal (111) is provided with n layers, the heat sink layer (112) is provided with 2n layers, and the heat insulation layer (113) is provided with n-1 layers. Each layer of the lath crystal (111) corresponds to two layers of the heat sink layer (112), and each layer of the lath crystal (111) is sandwiched between the corresponding two layers of the heat sink layer (112) to form a lath crystal component. Multiple lath crystal components are stacked sequentially, and a layer of the heat insulation layer (113) is sandwiched between two adjacent lath crystal components, wherein n is a positive integer and n≥2.

3. The laser amplification element according to claim 1 or 2, characterized in that, The heat sink layer (112) is a microchannel liquid cooling plate.

4. A laser amplification assembly, characterized in that, Includes a pump light source device (12) and a laser amplification element (11) as described in any one of claims 1-3, wherein the pump light source device (12) supplies pump light to the laser amplification element (11) so that the laser amplification element (11) amplifies the received seed light and outputs it.

5. The laser amplification assembly according to claim 4, characterized in that, It also includes a shaping and homogenizing optical path (13), a pump mirror (14), two pump shaping mirror groups (15), and two cavity mirror groups (16). The laser amplification element (11) is disposed between the two cavity mirror groups (16), and the two pump shaping mirror groups (15) are disposed on the side away from each other. The shaping and homogenizing optical path (13) and the pump mirror (14) are disposed on the side away from each other. The pump light source device (12) is disposed on the side away from each other. The homogenizing optical path (13) is located away from the laser amplification element (11). The pump light source device (12) emits pump light, which is then directed toward the laser amplification element (11) via the homogenizing optical path (13), the pump shaping mirror group (15), and the cavity mirror group (16) located close to it. The pump light emitted by the laser amplification element (11) is reflected by the pump reflector (14) and the cavity mirror group (16) and the pump shaping mirror group (15) on the corresponding side, and then reused by the laser amplification element (11).

6. The laser amplification assembly according to claim 5, characterized in that, It also includes two beam splitter groups (17). Each beam splitter group (17) is provided between the pump shaping mirror group (15) and the cavity mirror group (16) which are close to each other. The beam splitter group (17) close to the pump light source device (12) is used to split the pump light into multiple beams and direct them to multiple slab crystals (111). The pump light emitted from the multiple slab crystals (111) is combined by the other beam splitter group (17) and directed to the pump reflector (14). During the reflection, it is split into beams and directed to multiple slab crystals (111).

7. The laser amplification assembly according to claim 5, characterized in that, The cavity mirror group (16) includes two dichroic mirrors (161) and two cavity mirrors (162). The dichroic mirrors (161) transmit the pump light, and the dichroic mirrors (161) and cavity mirrors (162) reflect the seed light. The two dichroic mirrors (161) are located between the two cavity mirrors (162), and the two dichroic mirrors (161) and the two cavity mirrors (162) are distributed at intervals along the stacking direction of the multilayer lath crystals (111).

8. The laser amplification assembly according to any one of claims 4-7, characterized in that, The pump light source device (12) integrates multiple semiconductor bars (121).

9. A laser generator, characterized in that, The device includes a seed light source (2), an output optical path (3), and a laser amplification assembly (1) as described in any one of claims 4-8. The seed light source (2) is used to supply seed light to the laser amplification assembly (1), and the seed light is amplified by the laser amplification assembly (1) and then emitted by the output optical path (3).

10. The laser generator according to claim 9, characterized in that, The output optical path component (3) includes an isolator (31), an output shaping lens group (32), and a spatial filter device (33) arranged in sequence. The laser beam output by the laser amplification assembly (1) is output after passing through the isolator (31), the output shaping lens group (32), and the spatial filter device (33) in sequence.

11. The laser generator according to claim 9, characterized in that, It also includes a substrate (4), on which the laser amplification assembly (1), seed light source device (2) and output optical path device (3) are integrated, and at least part of the laser amplification assembly (1), seed light source device (2) and output optical path device (3) are disposed on the front side of the substrate (4), while the remaining part is disposed on the back side of the substrate (4).

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