Dual-channel laser amplification device and method

Abstract

The invention discloses a dual-channel laser amplification device and method, and belongs to the technical field of lasers, and the device comprises a first seed laser unit and a second seed laser unit which are used for outputting two seed lasers with different incident angles and different refractive indexes in a gain medium; the pumping module is used for generating pumping light to provide pumping conditions for power amplification of the two beams of seed laser; the thermal control module is used for providing working temperature control conditions for the whole device; the laser gain medium is used for receiving two beams of seed laser incident from different incident angles through the incident end face and emitting the seed laser at the same angle through the emergent end face after multiple times of total reflection with different paths in the gain medium; and the third laser beam output unit is used for combining the two beams of seed laser emitted at the same angle to obtain an output light beam after power amplification. Power amplification of two laser beams is realized based on the single laser gain module, the laser beam combining function is realized, and the integration level of the laser amplifier and the light beam combining system is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and particularly relates to a dual-channel laser amplification device and method. Background Art

[0002] With the rapid development of laser technology, various types of high-power lasers are increasingly widely used in various fields, thus correspondingly posing higher requirements for the technical maturity of laser products, especially in terms of engineering indicators such as volume, weight, and efficiency. Moreover, in many application scenarios, lasers are even required to have the output function of composite wavelength or composite pulse laser. For example, in the field of material processing, in order to achieve precise processing of composite materials, the corresponding laser processing system needs to have the operating characteristics of a multi-pulse regime, combining pulsed lasers with different pulse widths to obtain the best processing effect. Specifically, for example, combining nanosecond and picosecond pulsed lasers for output, or combining nanosecond and femtosecond pulsed lasers for output, or even combining nanosecond / picosecond / femtosecond pulsed lasers simultaneously for output, etc.

[0003] In response to the above demand for combined output, the Chinese patent application with the publication number CN116544763A provides a composite pulse laser and its working method. After the pump light is absorbed by the laser gain medium, two laser beams are generated; the first beam is reflected after reaching the polarization beam splitter, undergoes pulse generation through the first pulse modulation module, and then enters the first pulse laser resonator; the second beam is transmitted after reaching the polarization beam splitter, undergoes pulse generation through the second pulse modulation module, and then enters the second pulse laser resonator; the first and second beams are coupled and output through the coupling output mirror. The technical solution proposed by this invention has a simple structure, is compact in volume, and has the function of composite pulse laser output. However, due to the relatively low output power of the laser oscillator, its application range is limited.

[0004] Currently, in response to the demand for high-power composite laser sources in certain application scenarios, the prior art usually takes the approach of separately designing different power amplification modules for multiple individual lasers to increase the power, and then using an additional beam combining module to implement multi-beam synthesis to achieve high-power composite laser output. However, this solution will inevitably cause problems such as a complex structure, large volume, poor reliability, and high cost of the entire laser amplification system. Due to the increase in multiple power amplification modules and beam combining modules, not only does the volume and weight of the system increase significantly, but also the number of fault points and the maintenance difficulty of the system increase. At the same time, due to the coupling and matching problems between the modules, it is also easy to cause instability of the system performance and reduction of reliability.

[0005] Therefore, there is an urgent need to develop a laser amplification device that integrates multi-channel laser power amplification and beam combination, which should have the characteristics of compact structure, small volume, light weight, high efficiency and good reliability. It can meet the power amplification and beam combination requirements of multiple laser channels at the same time, and also has the characteristics of reducing the system cost and maintenance difficulty, so as to better provide technical support for the application of high-power composite laser sources and promote the application and development of laser technology in more fields. Summary of the Invention

[0006] In view of the above, the object of the present invention is to provide a dual-channel laser amplification device and method, which realizes the power amplification and combined beam output of two laser beams with different characteristics (including wavelength, pulse width, etc.) based on a single laser amplification module. While greatly increasing the output power of the composite laser, it also simplifies the traditional beam combination module. It can be used for the power amplification of some composite laser processing devices, or as a power pre-amplification module of some ultra-short and ultra-intense laser devices, which can effectively reduce the research and development cost and structural complexity of the laser system, thereby expanding the application scope of such laser systems.

[0007] To achieve the above object of the invention, the technical solution provided by the present invention is as follows: A dual-channel laser amplification device provided by an embodiment of the present invention includes: a first seed laser unit, a second seed laser unit, a pump module, a third laser beam output unit, a thermal control module, and a laser gain medium; The first seed laser unit and the second seed laser unit are used to output a first seed laser and a second seed laser with different incident angles and different refractive indices in the gain medium; The pump module is used to generate pump light to provide pump conditions for the power amplification of the first seed laser and the second seed laser; The thermal control module is used to provide working temperature control conditions for the entire device; The laser gain medium is used to receive the first seed laser and the second seed laser incident from different incident angles through the incident end face, so that the two seed lasers undergo several total internal reflections with different paths in the gain medium, and the two seed lasers are emitted from the exit end face at the same angle; The third laser beam output unit is used to combine the two seed lasers emitted at the same angle to obtain an output beam with amplified power.

[0008] Preferably, to realize that the two seed lasers undergo several total internal reflections with different paths in the gain medium and the two seed lasers are emitted from the exit end face at the same angle, the following conditions must be met: The wavelengths of the first and second seed lasers are λ1 and λ2 respectively, and the corresponding refractive indices in the gain medium are n1 and n2 respectively, with n1 > n2. The shape of the gain medium is trapezoidal, the length of the bottom surface of the trapezoid is L, the height of the trapezoid is h, the two base angles at the incident end and the output end are θ1 and θ2 respectively, the two side waists of the trapezoid are light-passing surfaces, the height of the output point of the output beam is h0, the output angle is α0, and the incident angles on the inner side of the output end of the gain medium before output are β and γ respectively. Then there are: α0 > γ > β, h0 < h; After the two seed lasers are totally reflected on the bottom surface of the gain medium, the angles with the bottom surface are θ3 and θ4 respectively, that is, the complementary angles of the total reflection incident angles of the two seed lasers on the bottom surface. Then there are: θ3 = π / 2 - θ1 - β; To ensure total reflection, the incident angle should be greater than the critical angle. Then there are: π / 2 - θ3 = θ1 + β > arcsin(1 / n1), π / 2 - θ4 = θ1 + γ > arcsin(1 / n2); Let the incident angle of the first seed laser at the incident end be α1, the incident point height be h1, and the refraction angle be α1'. According to the refraction law, sinα1 = n1sinα1'. According to the sum of interior angles of a triangle being π, α1' = θ2 + θ3 - π / 2. Then there are: sinα1 = n1sin(θ2 + θ3 - π / 2); Let the incident angle of the second seed laser at the incident end be α2, the incident point height be h2, and the refraction angle be α2'. According to the refraction law, sinα2 = n2sinα2'. According to the sum of interior angles of a triangle being π, α2' = θ2 + θ4 - π / 2. Then there are: sinα2 = n2sin(θ2 + θ4 - π / 2); To ensure that the two seed lasers are output and combined at the same angle at the output end face, there are: , where x and y are the number of total reflections of the first and second seed lasers in the gain medium respectively.

[0009] Preferably, when the wavelengths of the first and second seed lasers are the same and in the range of 1022 - 1065 nm, the polarization states of the two beams of light are both linearly polarized and have orthogonal polarization states. At this time, the gain medium in the laser gain medium uses an optically anisotropic crystal material. The wavelength range of the seed laser matches the optically anisotropic crystal material with a strong emission peak, ensuring that the seed laser can achieve an efficient energy absorption and amplification process in the gain medium.

[0010] Preferably, the optically anisotropic crystal material includes: Nd:YVO4, Nd:YLF, Nd:GdVO4, or Yb:KGW.

[0011] Preferably, when the wavelengths of the first seed laser and the second seed laser are different, a solid laser gain crystal or a transparent ceramic material with multiple emission peaks is used as the gain medium in the laser gain medium at this time.

[0012] Preferably, the solid laser gain crystal or the transparent ceramic material with multiple emission peaks includes: Nd:YAG, Nd:YVO4, Nd:YLF, Nd:GdVO4, or Tm:YLF.

[0013] Preferably, when the gain medium is Nd:YAG, the wavelengths of the first seed laser and the second seed laser are 1064 nm and 1319 nm respectively; when the gain medium is Nd:YVO4, the wavelengths of the first seed laser and the second seed laser are 1064 nm and 1342 nm respectively; when the gain medium is Nd:YLF, the wavelengths of the first seed laser and the second seed laser are 1047 nm and 1053 nm respectively; when the gain medium is Tm:YLF, the wavelengths of the first seed laser and the second seed laser are 1880 nm and 1908 nm respectively. The wavelength selection of the seed laser matches the fixed emission spectral lines of each gain medium material, ensuring that the radiation transition process can be maximally excited, improving the energy transfer efficiency, and enhancing the power and stability of the laser output.

[0014] Preferably, the working modes of the first seed laser unit and the second seed laser unit are both in pulse form, and their pulse widths are different, including combinations of microseconds and nanoseconds, nanoseconds and femtoseconds, nanoseconds and picoseconds, or picoseconds and femtoseconds.

[0015] Preferably, the wavelengths of the first seed laser and the second seed laser are both within the gain bandwidth of the gain medium. The pump module includes a semiconductor laser and a beam shaping device, and the wavelength of the pump light output by the semiconductor laser is within the absorption bandwidth of the gain medium. Under the excitation of the pump module, the activated ions in the laser gain medium transition to the upper energy level to obtain a considerable population inversion, providing a necessary condition for the power amplification of the first seed laser and the second seed laser.

[0016] Preferably, antireflection films are coated on the incident end face and the output end face of the laser gain medium for the first seed laser and the second seed laser, with a transmittance > 99%, and the medium form is a cylinder, a cuboid, a slab, or a disk.

[0017] Preferably, the thermal control module adopts a temperature control method of a thermoelectric cooler (TEC), direct water cooling, or a combination of both to control the temperature of the laser gain medium within the range of 16°C to 25°C. Considering that the pump source generally operates at room temperature (about 20°C), if the temperature is too high, the wavelength drifts and the absorption efficiency decreases; if it is too low, condensation may occur. Therefore, it is necessary to control the temperature of the laser gain medium within the above suitable temperature range through the thermal control module.

[0018] To achieve the above invention objective, an embodiment of the present invention further provides a dual-channel laser amplification method, which is implemented by using the above dual-channel laser amplification device, and includes the following steps: Generate a first seed laser and a second seed laser with different incident angles and refractive indexes in the gain medium through a first seed laser unit and a second seed laser unit, and make them incident on the incident end face of the laser gain medium; Start the pump module to generate pump light and make it incident on the laser gain medium. The pump light provides energy for the power amplification of the first seed laser and the second seed laser, so that the two seed lasers are amplified in the gain medium. At the same time, the thermal control module provides the working temperature control conditions for the entire device; Inside the laser gain medium, the first seed laser and the second seed laser undergo several total internal reflections with different paths according to their respective incident angles and refractive indexes in the gain medium, and make the two seed lasers after power amplification exit from the exit end face at the same angle and reach the third laser beam output unit to achieve the output of the beam after power amplification.

[0019] Compared with the prior art, the beneficial effects of the present invention at least include: The present invention combines the power amplification and dispersion functions of the gain medium for two paths of seed lasers. Through specific material and wavelength matching design of the gain medium, after the two paths of seeds incident at different incident angles are power-amplified in the medium material, they exit from the rear end face of the gain medium at the same exit angle. Based on a single laser amplification module, the power amplification and beam combination of two different lasers are simultaneously achieved. This technical solution has both the functions of power amplification and beam combination for dual-channel lasers, effectively improves the integration of the laser amplifier and the beam combination device, and has the characteristics of compact structure, small volume, light weight, high efficiency, good reliability, low cost, and easy maintenance. It is of great significance for promoting the practical application and engineering of high-power composite pulse laser systems. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a structural and optical path schematic diagram of a dual-channel laser amplification device provided by an embodiment of the present invention, where the specific symbol markings are as follows: 1. First seed laser unit; 2. Second seed laser unit; 3. Pumping module; 4. Third laser beam output unit; 5. Thermal control module; 6. Laser gain medium. Figure 2 It is a schematic diagram of the transmission path of laser in the gain medium and the beam combination principle provided by an embodiment of the present invention; Figure 3 It is an emission spectrum diagram of Nd:YLF crystal material cut by a provided by an embodiment of the present invention; Figure 4 It is a flow schematic diagram of a dual-channel laser amplification method provided by an embodiment of the present invention. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific implementation manners described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0023] The inventive concept of the present invention is as follows: Aiming at the problems of insufficient amplification power, complex system structure and high cost in the existing laser amplification devices, the embodiments of the present invention provide a dual-channel laser amplification device and method. By designing two beams of seed lasers with different incident angles and refractive indexes to independently propagate and synchronously amplify in the laser gain medium, and finally realizing power increase through beam combination, the overall output power is greatly improved, and the overall structural layout is compact, effectively reducing the maintenance difficulty and cost, providing a new solution for the development of laser amplification technology.

[0024] Figure 1 It is a structural and optical path schematic diagram of a dual-channel laser amplification device provided by an embodiment of the present invention. As Figure 1 shown, the embodiment provides a dual-channel laser amplification device, including: a first seed laser unit 1, a second seed laser unit 2, a pumping module 3, a third laser beam output unit 4, a thermal control module 5 and a laser gain medium 6.

[0025] Among them, the first seed laser unit 1 and the second seed laser unit 2 are used to output the first seed laser and the second seed laser with different incident angles and refractive indexes in the gain medium. The pump module 3 is used to generate pump light to provide pump conditions for the power amplification of the first seed laser and the second seed laser. The thermal control module 5 is used to provide working temperature control conditions for the entire device. The laser gain medium 6 is used to receive the first seed laser and the second seed laser incident from different incident angles through the incident end face, so that the two seed lasers undergo several total internal reflections with different paths in the gain medium, and the two seed lasers are output at the same angle through the output end face. The third laser beam output unit 4 is used to combine the two seed lasers output at the same angle to obtain an output beam with amplified power.

[0026] In the embodiment, as Figure 2 shown, taking the case where the two seed lasers undergo one total internal reflection in the gain medium as an example, the geometric dimensions of the gain medium, the cutting angle, and the relationship between the incident points and incident angles of the two seed lights are described. When the light beam undergoes multiple total internal reflections in the gain medium, the incident points and incident angles of the two seed lights can also be determined according to this method.

[0027] For a specific gain medium, the working wavelengths of two laser beams are selected as λ1 and λ2 respectively, and the corresponding refractive indexes are n1 and n2, and n1 > n2. The shape of the gain medium is trapezoidal, the length of the bottom surface of the trapezoid is L, the height of the trapezoid is h, the two base angles of the incident end and the output end are θ1 and θ2 respectively, and the two side waists of the trapezoid are light-transmitting surfaces. Assume that two seed lasers (incident light 1 and incident light 2) are incident from the left side of the gain medium and are combined and output from the right side. The height of the output point is h0, the output angle is α0, and the incident angles on the right side surface are β and γ respectively. Obviously, there are: α0 > γ > β, h0 < h; After the two beams of light undergo total internal reflection on the bottom surface, the angles with the bottom surface are θ3 and θ4 respectively. Obviously, they are the complementary angles of the incident angles of the two beams of light during total internal reflection on the bottom surface. According to the geometric relationship, there are: θ3 = π / 2 - θ1 - β.

[0028] To ensure total internal reflection, the incident angle should be greater than the critical angle. Therefore, there is: π / 2 - θ3 = θ1 + β > arcsin(1 / n1), Similarly, there should be: π / 2 - θ4 = θ1 + γ > arcsin(1 / n2); Let the incident angle of the first seed laser (incident light 1) on the left side be α1, the incident point height be h1, and the refraction angle be α1'. According to the refraction law, sinα1 = n1sinα1'. According to the fact that the sum of the interior angles of a triangle is π, it can be known that α1' = θ2 + θ3 - π / 2. Therefore, sinα1 = n1sin(θ2 + θ3 - π / 2); Similarly, let the incident angle of the second seed laser (incident light 2) at the incident end be α2, the height of the incident point be h2, and the refraction angle be α2'. According to the law of refraction, sinα2 = n2sinα2'. According to the fact that the sum of the interior angles of a triangle is π, it can be known that α2' = θ2 + θ4 - π / 2. Therefore, sinα2 = n2sin(θ2 + θ4 - π / 2).

[0029] To ensure that the two seed lasers are emitted at the same angle and combined and output at the output end face, there is: , where x and y are the number of total internal reflections of the first seed laser and the second seed laser in the gain medium, respectively.

[0030] In the embodiment, the output wavelengths of the first seed laser and the second seed laser are selected to be 1047 nm and 1314 nm, respectively. Correspondingly, the gain medium is a plate-shaped Nd:YLF crystal cut along the a-axis, the doping concentration of neodymium ions in the crystal is 1.0 at.%, the size is 60 mm (length of the trapezoidal bottom surface) × 8 mm (width of the crystal) × 3 mm (height of the trapezoid), the shape is trapezoidal, the bottom wedge angle is 60°, the large surfaces and end faces of the plate are strictly polished at the optical level, and antireflection films for 1047 nm and 1314 nm lasers are coated on the left and right two light-transmitting surfaces (incident end face and output end face), and the transmittance > 99.6%. An antireflection film for 880 nm pump light is coated on the upper large surface of the plate, and a high-reflection film for 880 nm pump light is coated on the lower large surface of the plate. A layer of evanescent wave protective film is coated on the upper and lower large surfaces of the plate to prevent the total internal reflection of the oscillating laser between these two surfaces from being damaged by mechanical installation and sealing parts.

[0031] The pump light is pumped by a semiconductor laser array (LDA) with a wavelength of 880 nm, and its temperature is adjusted so that the pump wavelength is aligned with the absorption peak of the Nd:YLF crystal. After the pump light is emitted from the LDA, it passes through the pump light shaping system to homogenize the pump light and is coupled into the upper large surface of the plate. The lower large surface of the plate is cooled and precisely temperature-controlled by a copper heat sink with constant-temperature circulating water, and the temperature control accuracy is 16°C ± 0.1°C, ensuring the continuous and stable operation of the laser amplification process.

[0032] According to as Figure 3As can be seen from the emission cross-section spectrum shown, the main peak of its emission spectrum is located at 1047 nm, and the secondary peak is located at 1314 nm. Although there are slight differences in the emission cross-section, the Nd:YLF crystal in the population inversion state can provide gain for the lasers at these two wavelengths to achieve power amplification, especially under the condition of no spectral line competition. Therefore, the wavelength of the first seed laser is designed to be 1047 nm, and its refractive index in the gain medium is n1, and the wavelength of the second seed laser is 1314 nm, and its refractive index in the gain medium is n2. According to the dispersion equation of the Nd:YLF crystal at room temperature (shown below, unit: μm), n1 = 1.448 and n2 = 1.446 can be calculated. Obviously, n1 > n2.

[0033] , , wherein, represents the refractive index of the o-ray (ordinary ray), represents the refractive index of the e-ray (extraordinary ray), represents the laser wavelength. According to the refractive indices of the two beams of light in the crystal, the critical angles of total internal reflection of the two beams of light in the crystal are calculated to be 43.68° and 43.75° respectively. Therefore, by reasonably designing the incident angles of the two seed lasers and the crystal tilt angle, the total internal reflection condition can be fully satisfied. At the same time, due to the refractive index difference of the two seed lasers in the crystal, in the case of non-normal incidence, when the two beams of light are incident on the crystal at a certain same incident angle, they will be transmitted along different paths and finally exit at different exit angles. According to the principle of reversibility of light path, when the two beams of light are incident on the crystal at these two different incident angles respectively, they will finally exit from the crystal at the same exit angle, thereby realizing power amplification and common aperture synthesis of the light beam. The difference in the transmission light path can effectively avoid the gain competition effect that may be caused during the power amplification process, thereby improving the overall energy extraction efficiency of the laser amplifier.

[0034] Based on the same inventive concept, as Figure 4 shown, the embodiment of the present invention also provides a dual-channel laser amplification method, including the following steps: S1, generate a first seed laser and a second seed laser with different incident angles and refractive indices in the gain medium through a first seed laser unit and a second seed laser unit, and incident them on the incident end face of the laser gain medium.

[0035] S2, start the pump module to generate pump light and incident it into the laser gain medium, provide energy for the power amplification of the first seed laser and the second seed laser through the pump light, so that the two seed lasers are amplified in the gain medium, and at the same time, provide the working temperature control condition for the whole device through the thermal control module.

[0036] S3. Inside the laser gain medium, the first seed laser and the second seed laser undergo multiple total internal reflections with different paths in the gain medium according to their respective incident angles and refractive indices, and the two amplified seed lasers are output from the output end face at the same angle to the third laser beam output unit to achieve the output of the amplified beam.

[0037] The specific embodiments described above have elaborated on the technical solutions and beneficial effects of the present invention. It should be understood that the above is only the most preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, supplements, equivalent replacements, etc. made within the scope of the principles of the present invention should be included in the protection scope of the present invention, including but not limited to the increase in the number of laser amplification channels, the replacement of the laser gain medium material, the increase in the number of times (number of passes) of the seed beam transmitted in the laser gain medium, etc.

Claims

1. A dual-channel laser amplification device, characterized in that, It includes: A first seed laser unit, a second seed laser unit, a pump module, a third laser beam output unit, a thermal control module, and a laser gain medium; The first seed laser unit and the second seed laser unit are used to output a first seed laser and a second seed laser with different incident angles and different refractive indexes in the gain medium; The pump module is used to generate pump light to provide pump conditions for power amplification of the first seed laser and the second seed laser; The thermal control module is used to provide working temperature control conditions for the entire device; The laser gain medium is used to receive the first seed laser and the second seed laser incident from different incident angles through the incident end face, cause the two seed lasers to undergo multiple total reflections with different paths in the gain medium, and output the two seed lasers at the same angle through the output end face; The third laser beam output unit is used to combine the two seed lasers output at the same angle to obtain an output beam with amplified power.

2. The dual-channel laser amplification device according to claim 1, wherein, To achieve multiple total reflections with different paths of the two seed lasers in the gain medium and output the two seed lasers at the same angle through the output end face, the following conditions must be met: The wavelengths of the first seed laser and the second seed laser are λ1 and λ2 respectively, and the corresponding refractive indexes in the gain medium are n1 and n2 respectively, and n1 > n2. The shape of the gain medium is trapezoidal, the length of the bottom surface of the trapezoid is L, the height of the trapezoid is h, the two base angles at the incident end and the output end are θ1 and θ2 respectively, the two side waists of the trapezoid are light-transmitting surfaces, the height of the output point of the output beam is h0, the exit angle is α0, and the incident angles on the inner side of the output end of the gain medium before output are β and γ respectively. Then there are: α0 > γ > β, h0 < h; The angles between the two seed lasers and the bottom surface after total reflection on the bottom surface of the gain medium are θ3 and θ4 respectively, that is, the complementary angles of the incident angles of total reflection of the two seed lasers on the bottom surface. Then there are: θ3 = π / 2 - θ1 - β; To ensure total reflection, the incident angle should be greater than the critical angle. Then there are: π / 2 - θ3 = θ1 + β > arcsin(1 / n1), π / 2 - θ4 = θ1 + γ > arcsin(1 / n2); Let the incident angle of the first seed laser at the incident end be α1, the incident point height be h1, and the refraction angle be α1'. According to the refraction law, sinα1 = n1sinα1'. According to the sum of interior angles of a triangle being π, α1' = θ2 + θ3 - π / 2. Then there are: sinα1 = n1sin(θ2 + θ3 - π / 2); Let the incident angle of the second seed laser at the incident end be α2, the incident point height be h2, and the refraction angle be α2'. According to the refraction law, sinα2 = n2sinα2'. According to the sum of interior angles of a triangle being π, α2' = θ2 + θ4 - π / 2. Then there are: sinα2 = n2sin(θ2 + θ4 - π / 2); To ensure that the two seed lasers are output and combined at the same angle at the output end face, there are: ， Where x and y are the number of total reflections of the first seed laser and the second seed laser in the gain medium respectively.

3. The dual-channel laser amplification device according to claim 1, wherein, When the wavelengths of the first and second seed lasers are the same and in the range of 1022 - 1065 nm, and the polarization states of the two beams of light are both linearly polarized and have orthogonal polarization states, the gain medium in the laser gain medium adopts an optically anisotropic crystal material at this time.

4. The dual-channel laser amplification device according to claim 3, wherein, The optically anisotropic crystal materials include: Nd:YVO4, Nd:YLF, Nd:GdVO4, or Yb:KGW.

5. The dual-channel laser amplification device according to claim 1, characterized in that When the wavelengths of the first and second seed lasers are different, the gain medium in the laser gain medium adopts a solid laser gain crystal or a transparent ceramic material with multiple emission peaks at this time.

6. The dual-channel laser amplification device according to claim 5, wherein, The solid laser gain crystal or transparent ceramic material with multiple emission peaks includes: Nd:YAG, Nd:YVO4, Nd:YLF, Nd:GdVO4, or Tm:YLF.

7. The dual-channel laser amplification device according to claim 6, wherein, When the gain medium is Nd:YAG, the wavelengths of the first and second seed lasers are 1064 nm and 1319 nm respectively; when the gain medium is Nd:YVO4, the wavelengths of the first and second seed lasers are 1064 nm and 1342 nm respectively; when the gain medium is Nd:YLF, the wavelengths of the first and second seed lasers are 1047 nm and 1053 nm respectively; when the gain medium is Tm:YLF, the wavelengths of the first and second seed lasers are 1880 nm and 1908 nm respectively.

8. The dual-channel laser amplification device according to claim 1, wherein The working modes of the first seed laser unit and the second seed laser unit are both in pulse form, and their pulse widths are different, including combinations of microseconds and nanoseconds, nanoseconds and femtoseconds, nanoseconds and picoseconds, or picoseconds and femtoseconds.

9. The dual-channel laser amplification device according to claim 1, wherein Both the incident end face and the output end face of the laser gain medium are coated with an antireflection film for the first and second seed lasers, with a transmittance > 99%. The medium form is a cylinder, a cuboid, a slab, or a disc.

10. A dual-channel laser amplification method is realized by using the above-mentioned dual-channel laser amplification device, characterized in that It includes the following steps: Generate the first and second seed lasers with different incident angles and refractive indices in the gain medium through the first seed laser unit and the second seed laser unit, and make them incident on the incident end face of the laser gain medium; Start the pump module to generate pump light and make it incident on the laser gain medium. Provide energy for the power amplification of the first and second seed lasers through the pump light, so that the two beams of seed lasers are amplified in the gain medium. At the same time, provide the working temperature control conditions for the entire device through the thermal control module; In the laser gain medium, the first and second seed lasers undergo several total internal reflections with different paths in the gain medium according to their respective incident angles and refractive indices, and make the two beams of seed lasers after power amplification exit from the output end face at the same angle to the third laser beam output unit to achieve the output of the beam after power amplification.

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