Dual-channel laser amplification device and method

Abstract

The present invention discloses a dual-channel laser amplification device and method, belonging to the field of laser technology. The device comprises: a first seed laser unit and a second seed laser unit for outputting two seed laser beams with different incident angles and refractive indices in a gain medium; a pump module for generating pump light to provide pumping conditions for power amplification of the two seed laser beams; a thermal control module for providing operating temperature control conditions for the entire device; a laser gain medium for receiving two seed laser beams incident at different incident angles through an incident end face, and after undergoing several total reflections with different paths within the gain medium, emitting the two seed laser beams at the same angle through an exit end face; and a third laser beam output unit for combining the two seed laser beams emitted at the same angle to produce a power-amplified output beam. The present invention uses a single laser gain module to achieve power amplification of two laser beams and has a laser beam combining function, effectively improving the integration of the laser amplifier and beam combining system.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and in particular 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 used in various fields, which in turn puts higher requirements on the technical maturity of laser products, especially in terms of engineering indicators such as volume, weight and efficiency. In addition, in many applications, lasers are even required to have the output function of composite wavelength or composite pulse lasers. 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 multi-pulse system operation characteristics, combining pulse lasers with different pulse widths to obtain the best processing effect. Specifically, for example, nanosecond and picosecond pulse lasers can be combined to output, or nanosecond and femtosecond pulse lasers can be combined to output, or nanosecond / picosecond / femtosecond pulse lasers can be combined to output at the same time, etc.

[0003] To address the need for this combined output, Chinese patent application CN116544763A proposes a composite pulse laser and its operating method. Pump light is absorbed by a laser gain medium to generate two laser beams. The first beam is reflected by a polarization beam splitter, passes through a first pulse modulation module to generate pulses, and then enters a first pulse laser resonant cavity. The second beam is transmitted by a polarization beam splitter, passes through a second pulse modulation module to generate pulses, and then enters a second pulse laser resonant cavity. The first and second beams are coupled out via a coupling output mirror. This invention offers a simple, compact structure and composite pulse laser output capability. However, the relatively low output power of the laser oscillator limits its application.

[0004] Currently, to meet the demand for high-power composite laser sources in certain applications, existing technologies typically design different power amplifier modules for multiple individual lasers to boost their power, and then use additional beam combining modules to implement multi-beam synthesis to achieve high-power composite laser output. However, this approach inevitably leads to problems such as complex structure, large size, poor reliability, and high cost for the entire laser amplification system. The addition of multiple power amplifier modules and beam combining modules not only significantly increases the size and weight of the system, but also increases the number of system failure points and maintenance difficulties. At the same time, due to coupling and matching issues between modules, it is also easy to cause unstable system performance and reduced reliability.

[0005] Therefore, there is an urgent need to develop a laser amplification device that integrates multi-channel laser power amplification and beam synthesis. It should have the characteristics of compact structure, small size, light weight, high efficiency and good reliability. It can simultaneously meet the power amplification and beam synthesis requirements of multiple laser channels, and at the same time have the characteristics of reducing system costs 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 purpose of the present invention is to provide a dual-channel laser amplification device and method, which can realize power amplification and beam combining output of two laser beams with different characteristics (including wavelength, pulse width, etc.) based on a single laser amplification module. While greatly improving the output power of the composite laser, it also simplifies the traditional beam combining module. It can be used for power amplification of certain composite laser processing devices, or as a power pre-amplification module for certain ultrashort and ultra-intense laser devices, which can effectively reduce the development cost and structural complexity of the laser system, thereby expanding the application range of such laser systems.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0008] An embodiment of the present invention provides a dual-channel laser amplification device, comprising: 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;

[0009] The first seed laser unit and the second seed laser unit are used to output two beams of first seed laser and second seed laser with different incident angles and refractive indices in the gain medium;

[0010] The pump module is used to generate pump light to provide pumping conditions for power amplification of the first seed laser and the second seed laser;

[0011] The thermal control module is used to provide operating temperature control conditions for the entire device;

[0012] The laser gain medium is used to receive the first seed laser and the second seed laser incident at different incident angles through the incident end face, so that the two seed laser beams undergo several total reflections with different paths in the gain medium, and emit the two seed laser beams at the same angle through the output end face;

[0013] The third laser beam output unit is used to combine two seed laser beams emitted at the same angle to obtain a power-amplified output beam.

[0014] Preferably, in order to achieve a plurality of total reflections of different paths in the gain medium for the two seed laser beams and to emit the two seed laser beams at the same angle through the output end face, the following conditions must be met:

[0015] The wavelengths of the first seed laser and the second seed laser are λ1 and λ2, respectively. The corresponding refractive indices in the gain medium are n1 and n2, respectively, and n1>n2. The shape of the gain medium is a trapezoid, the bottom length of the trapezoid is L, the height of the trapezoid is h, the bottom angles of the incident end and the output end are θ1 and θ2, respectively. The waists on both sides of the trapezoid are the clear surfaces. The output point height of the output beam is h0, the output angle is α0, and the incident angles on the inner side of the gain medium output end before output are β and γ, respectively. Then:

[0016] α0>γ>β, h0<h;

[0017] The angles between the two seed laser beams and the bottom surface after total reflection at the bottom surface of the gain medium are θ3 and θ4, that is, the complementary angles of the total reflection incident angles of the two seed laser beams at the bottom surface, and then:

[0018] θ3=π / 2-θ1-β;

[0019] To ensure total reflection, the incident angle should be greater than the critical angle, then:

[0020] π / 2-θ3=θ1+β>arcsin(1 / n1),

[0021] π / 2-θ4=θ1+γ>arcsin(1 / n2);

[0022] Assume that the incident angle of the first seed laser at the incident end is α1, the incident point height is h1, and the refraction angle is α1'. According to the law of refraction, sinα1=n1sinα1'. According to the sum of the interior angles of a triangle is π, α1'=θ2+θ3-π / 2, then:

[0023] sinα1=n1sin(θ2+θ3-π / 2);

[0024] Assume that the incident angle of the second seed laser at the incident end is α2, the incident point height is h2, and the refraction angle is α2'. According to the law of refraction, sinα2=n2sinα2'. According to the sum of the interior angles of a triangle is π, α2'=θ2+θ4-π / 2, then:

[0025] sinα2=n2sin(θ2+θ4-π / 2);

[0026] To ensure that the two seed laser beams are emitted at the same angle and combined at the output end, we have:

[0027] ,

[0028] Here, x and y are the times of total reflection of the first seed laser and the second seed laser in the gain medium, respectively.

[0029] Preferably, when the wavelengths of the first and second seed lasers are identical and within the 1022-1065 nm range, and the polarization states of both beams are linearly polarized and have orthogonal polarization states, the gain medium in the laser gain medium is constructed of an optically anisotropic crystal material. The wavelength range of the seed lasers matches the optically anisotropic crystal material with a strong emission peak, ensuring efficient energy absorption and amplification of the seed lasers in the gain medium.

[0030] Preferably, the optically anisotropic crystal material includes: Nd:YVO4, Nd:YLF, Nd:GdVO4 or Yb:KGW.

[0031] Preferably, when the wavelengths of the first seed laser and the second seed laser are different, the gain medium in the laser gain medium is a solid laser gain crystal or a transparent ceramic material with multiple emission peaks.

[0032] Preferably, 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.

[0033] Preferably, when the gain medium is Nd:YAG, the wavelengths of the first and second seed lasers are 1064nm and 1319nm, respectively; when the gain medium is Nd:YVO4, the wavelengths of the first and second seed lasers are 1064nm and 1342nm, respectively; when the gain medium is Nd:YLF, the wavelengths of the first and second seed lasers are 1047nm and 1053nm, respectively; and when the gain medium is Tm:YLF, the wavelengths of the first and second seed lasers are 1880nm and 1908nm, respectively. The seed laser wavelengths are selected to match the fixed emission lines of each gain medium material, ensuring maximum excitation of its radiative transition process, improving energy transfer efficiency, and enhancing the power and stability of the laser output.

[0034] Preferably, the first seed laser unit and the second seed laser unit both operate in pulsed form, and their pulse widths are different, including a combination of microseconds and nanoseconds, a combination of nanoseconds and femtoseconds, a combination of nanoseconds and picoseconds, or a combination of picoseconds and femtoseconds.

[0035] Preferably, the wavelengths of both the first and second seed lasers are within the gain bandwidth of the gain medium. The pump module comprises 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 stimulation of the pump module, the activated ions in the laser gain medium transition to the upper energy level, achieving a significant inversion population, which provides the necessary conditions for power amplification of the first and second seed lasers.

[0036] Preferably, both the incident end face and the output end face of the laser gain medium are coated with antireflection films for the first seed laser and the second seed laser, with a transmittance greater than 99%, and the medium is in the shape of a cylinder, a cuboid, a slab, or a disc.

[0037] Preferably, the thermal control module uses a TEC (Technical Electron Cooler), direct water cooling, or a combination of both to maintain the temperature of the laser gain medium within a range of 16°C to 25°C. Considering that the pump source generally operates at room temperature (around 20°C), excessively high temperatures can cause wavelength drift and reduced absorption efficiency, while excessively low temperatures can lead to condensation. Therefore, the thermal control module is required to maintain the temperature of the laser gain medium within this optimal range.

[0038] To achieve the above-mentioned object of the invention, an embodiment of the present invention further provides a dual-channel laser amplification method, which is implemented using the above-mentioned dual-channel laser amplification device and includes the following steps:

[0039] Generate two beams of first seed laser and second seed laser with different incident angles and refractive indexes 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;

[0040] The pump module is activated to generate pump light that is incident on the laser gain medium. The pump light provides energy for 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 operating temperature control conditions for the entire device.

[0041] In the laser gain medium, the first seed laser and the second seed laser undergo several total reflections with different paths according to their respective incident angles and refractive indices in the gain medium, and the two power-amplified seed laser beams are emitted at the same angle through the output end face to the third laser beam output unit to realize the output of the power-amplified beams.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] This invention combines the power amplification and dispersion functions of the gain medium for two seed lasers. By implementing a specific material and wavelength design for the gain medium, two seeds incident at different angles of incidence are power amplified within the dielectric material and then emitted from the rear facet of the gain medium at the same exit angle. This achieves simultaneous power amplification and beam combining of two different lasers using a single laser amplification module. This technical solution combines the power amplification and beam combining functions of dual-channel lasers, effectively improving the integration of laser amplifiers and beam combining devices. It features a compact structure, small size, 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 This is a schematic diagram of the structure and optical path of a dual-channel laser amplification device provided by an embodiment of the present invention, wherein the specific symbols are as follows: 1. first seed laser unit; 2. second seed laser unit; 3. pump module; 4. third laser beam output unit; 5. thermal control module; 6. laser gain medium;

[0046] Figure 2 This is a schematic diagram of the transmission path and beam combining principle of the laser in the gain medium provided by an embodiment of the present invention;

[0047] Figure 3 This is an emission spectrum diagram of an a-cut Nd:YLF crystal material provided by an embodiment of the present invention;

[0048] Figure 4 It is a flow chart of a dual-channel laser amplification method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0050] The inventive concept of the present invention is: to address the problems of insufficient amplification power, complex system structure and high cost in laser amplification devices in the prior art, the embodiments of the present invention provide a dual-channel laser amplification device and method. By designing two seed laser beams with different incident angles and refractive indices to propagate independently and amplify synchronously in the laser gain medium, power is finally increased by beam combining, greatly improving the overall output power. The overall structural layout is compact, which effectively reduces the difficulty and cost of maintenance, and provides a new solution for the development of laser amplification technology.

[0051] Figure 1 This is a schematic diagram of the structure and optical path of a dual-channel laser amplification device provided by an embodiment of the present invention. Figure 1As shown, the embodiment provides a dual-channel laser amplification device, including: a first seed laser unit 1, a second seed laser unit 2, a pump module 3, a third laser beam output unit 4, a thermal control module 5 and a laser gain medium 6.

[0052] Among them, the first seed laser unit 1 and the second seed laser unit 2 are used to output two beams of the first seed laser and the second seed laser with different incident angles and refractive indices in the gain medium. The pump module 3 is used to generate pump light to provide pumping conditions for the power amplification of the first seed laser and the second seed laser. The thermal control module 5 is used to provide operating 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 laser beams undergo several total reflections with different paths in the gain medium, and the two seed laser beams are emitted at the same angle through the exit end face. The third laser beam output unit 4 is used to combine the two seed laser beams emitted at the same angle to obtain an output beam after power amplification.

[0053] In the embodiment, Figure 2 As shown, taking the case of two seed laser beams undergoing one total reflection in the gain medium as an example, the relationship between the geometric dimensions of the gain medium, the cutting angle, the incident point and the incident angle of the two seed beams is explained. When the light beams undergo multiple total reflections in the gain medium, the incident point and incident angle of the two seed beams can also be determined according to this method.

[0054] For a specific gain medium, the operating wavelengths of the two lasers are selected to be λ1 and λ2, respectively, and the corresponding refractive indices are n1 and n2, respectively, with n1>n2. The shape of the gain medium is a trapezoid, with a base length of L and a height of h. The two base angles at the incident and output ends are θ1 and θ2, respectively, and the waists on both sides of the trapezoid are the light-clear surfaces. Assume that two seed laser beams (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 exit point height is h0, the exit angle is α0, and the incident angles on the right side are β and γ, respectively. Obviously,

[0055] α0>γ>β, h0<h;

[0056] After the two beams of light are totally reflected on the bottom surface, the angles between them and the bottom surface are θ3 and θ4 respectively. Obviously, they are the complementary angles of the incident angles of the two beams of light totally reflected on the bottom surface. According to the geometric relationship, we have:

[0057] θ3=π / 2-θ1-β.

[0058] To ensure total reflection, the angle of incidence should be greater than the critical angle, so:

[0059] π / 2-θ3=θ1+β>arcsin(1 / n1),

[0060] Similarly, there should be:

[0061] π / 2-θ4=θ1+γ>arcsin(1 / n2);

[0062] Assume that the incident angle of the first seed laser (incident light 1) on the left is α1, the incident point height is h1, and the refraction angle is α1'. According to the law of refraction, sinα1=n1sinα1'. Since the sum of the interior angles of a triangle is π, α1'=θ2+θ3-π / 2, so sinα1=n1sin(θ2+θ3-π / 2);

[0063] Similarly, assume that the incident angle of the second seed laser (incident light 2) at the incident end is α2, the incident point height is h2, and the refraction angle is α2'. According to the law of refraction, sinα2=n2sinα2'. Since the sum of the interior angles of a triangle is π, α2'=θ2+θ4-π / 2, so sinα2=n2sin(θ2+θ4-π / 2).

[0064] To ensure that the two seed laser beams are emitted at the same angle and combined at the output end, we have:

[0065] ,

[0066] Wherein, x and y are the times of total reflection of the first seed laser and the second seed laser in the gain medium, respectively.

[0067] In this embodiment, the output wavelengths of the first and second seed lasers are selected to be 1047 nm and 1314 nm, respectively. Accordingly, the gain medium is a slab-shaped Nd:YLF crystal cut along the a-axis, with a neodymium ion doping concentration of 1.0 at.%. The crystal has a trapezoidal shape with dimensions of 60 mm (trapezoidal base length) × 8 mm (crystal width) × 3 mm (trapezoidal height), and a base wedge angle of 60°. The slab's large and end faces are rigorously polished to optical quality. The left and right light-transmitting surfaces (the incident and exiting end faces) are coated with an antireflection coating for 1047 nm and 1314 nm lasers, achieving a transmittance of >99.6%. An 880 nm pump light antireflection coating is applied to the upper large surface of the slab, while an 880 nm pump light high-reflection coating is applied to the lower large surface. An evanescent wave protective coating is applied to both the upper and lower large surfaces of the slab to prevent total internal reflection of the oscillating laser light between these two surfaces from being damaged by mechanical mounting and sealing components.

[0068] The pump light is generated by a semiconductor laser array (LDA) with an 880nm wavelength. Its temperature is adjusted to align the pump wavelength with the absorption peak of the Nd:YLF crystal. After exiting the LDA, the pump light passes through a pump beam shaping system, homogenizing the pump light and coupling it into the upper surface of the slat. The lower surface of the slat is cooled and precisely temperature-controlled using a copper heat sink with constant-temperature circulating water. The temperature control accuracy is 16°C ± 0.1°C, ensuring continuous and stable operation of the laser amplification process.

[0069] According to Figure 3 The emission cross-section spectrum shown shows a primary peak at 1047nm and a secondary peak at 1314nm. Despite slight differences in the emission cross-sections, the Nd:YLF crystal in a population-inverted state can provide gain for both wavelengths, achieving power amplification, especially in the absence of spectral line competition. To this end, the wavelength of the first seed laser is designed to be 1047nm, with a refractive index n1 within the gain medium. The wavelength of the second seed laser is designed to be 1314nm, with a refractive index n2 within the gain medium. Based on the dispersion equation for the Nd:YLF crystal at room temperature (shown below, in μm), n1 = 1.448 and n2 = 1.446. Clearly, n1 > n2.

[0070] ,

[0071] ,

[0072] in, represents the refractive index of o-light (ordinary light), represents the refractive index of e-ray (extraordinary light), Represents the laser wavelength. According to the refractive index of the two beams of light in the crystal, the critical angles for their total reflection in the crystal are 43.68° and 43.75° respectively. Therefore, by reasonably designing the incident angle of the two seed lasers and the crystal bevel angle, the total reflection condition can be fully met. At the same time, due to the difference in refractive index 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 the same incident angle, they will be transmitted along different paths and eventually emitted at different exit angles. According to the principle of optical path reversibility, when the two beams of light are incident on the crystal at these two different incident angles, they will eventually be emitted from the crystal at the same exit angle, thereby realizing the power amplification and common aperture synthesis of the light beams. The difference in transmission optical paths 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.

[0073] Based on the same inventive concept, Figure 4 As shown, an embodiment of the present invention further provides a dual-channel laser amplification method, comprising the following steps:

[0074] S1 , generating two beams of first seed laser and 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 incident on an incident end face of the laser gain medium.

[0075] S2, start the pump module to generate pump light to be incident on the laser gain medium, and 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 conditions for the entire device through the thermal control module.

[0076] S3, in the laser gain medium, the first seed laser and the second seed laser undergo several total reflections with different paths in the gain medium according to their respective incident angles and refractive indices, and the two beams of power-amplified seed lasers are emitted at the same angle through the output end face to the third laser beam output unit to realize the output of the power-amplified beams.

[0077] The specific embodiments described above provide a detailed description of 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 intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention shall be included in the scope of protection of the present invention, including but not limited to increasing the number of laser amplification channels, replacing laser gain medium materials, and increasing the number of times (number of passes) that the seed beam is transmitted in the laser gain medium.

Claims

1. A dual-channel laser amplification device, characterized in that: include: 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 two beams of first seed laser and second seed laser with different incident angles and refractive indices in the gain medium; The pump module is used to generate pump light to provide pumping conditions for power amplification of the first seed laser and the second seed laser; The thermal control module is used to provide operating 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 at different incident angles through the incident end face, so that the two seed laser beams undergo several total reflections with different paths in the gain medium, and emit the two seed laser beams at the same angle through the output end face; The third laser beam output unit is used to combine two seed laser beams emitted at the same angle to obtain a power-amplified output beam.

2. The dual-channel laser amplification device according to claim 1, characterized in that: In order to achieve multiple total reflections of the two seed laser beams along different paths in the gain medium and emit them 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. The corresponding refractive indices in the gain medium are n1 and n2, respectively, and n1>n2. The shape of the gain medium is a trapezoid, the bottom length of the trapezoid is L, the height of the trapezoid is h, the bottom angles of the incident end and the output end are θ1 and θ2, respectively. The waists on both sides of the trapezoid are the clear surfaces. The output point height of the output beam is h0, the output angle is α0, and the incident angles on the inner side of the gain medium output end before output are β and γ, respectively. Then: α0>γ>β, h0<h; After the two seed laser beams are totally reflected at the bottom surface of the gain medium, the included 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 laser beams at the bottom surface, then: θ3=π / 2-θ1-β; To ensure total reflection, the incident angle should be greater than the critical angle, then: π / 2-θ3=θ1+β>arcsin(1 / n1), π / 2-θ4=θ1+γ>arcsin(1 / n2); Assume that the incident angle of the first seed laser at the incident end is α1, the incident point height is h1, and the refraction angle is α1'. According to the law of refraction, sinα1=n1sinα1'. According to the sum of the interior angles of a triangle is π, α1'=θ2+θ3-π / 2, then: sinα1=n1sin(θ2+θ3-π / 2); Assume that the incident angle of the second seed laser at the incident end is α2, the incident point height is h2, and the refraction angle is α2'. According to the law of refraction, sinα2=n2sinα2'. According to the sum of the interior angles of a triangle is π, α2'=θ2+θ4-π / 2, then: sinα2=n2sin(θ2+θ4-π / 2); To ensure that the two seed laser beams are emitted at the same angle and combined at the output end, we have: ， Wherein, x and y are the times of total reflection 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, characterized in that: When the wavelengths of the first seed laser and the second seed laser are the same and in the range of 1022-1065 nm, the polarization states of the two beams are both linearly polarized and have orthogonal polarization states. At this time, the gain medium in the laser gain medium adopts an optically anisotropic crystal material.

4. The dual-channel laser amplification device according to claim 3, characterized in that: The optically anisotropic crystal material includes: 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 seed laser and the second seed laser are different, the gain medium in the laser gain medium is a solid laser gain crystal or a transparent ceramic material with multiple emission peaks.

6. The dual-channel laser amplification device according to claim 5, characterized in that: 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, characterized in that: When the gain medium is Nd:YAG, the wavelengths of the first seed laser and the second seed laser are 1064nm and 1319nm respectively; when the gain medium is Nd:YVO4, the wavelengths of the first seed laser and the second seed laser are 1064nm and 1342nm respectively; when the gain medium is Nd:YLF, the wavelengths of the first seed laser and the second seed laser are 1047nm and 1053nm respectively; when the gain medium is Tm:YLF, the wavelengths of the first seed laser and the second seed laser are 1880nm and 1908nm respectively.

8. The dual-channel laser amplification device according to claim 1, characterized in that: The first seed laser unit and the second seed laser unit both work in a pulsed form, and their pulse widths are different, including a combination of microseconds and nanoseconds, a combination of nanoseconds and femtoseconds, a combination of nanoseconds and picoseconds, or a combination of picoseconds and femtoseconds.

9. The dual-channel laser amplification device according to claim 1, characterized in that: The incident end face and the output end face of the laser gain medium are both coated with anti-reflection films for the first seed laser and the second seed laser, with a transmittance greater than 99%. The medium is in the shape of a cylinder, a rectangular parallelepiped, a slab, or a disc.

10. A dual-channel laser amplification method, implemented using the dual-channel laser amplification device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Generate two beams of first seed laser and second seed laser with different incident angles and refractive indexes 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; The pump module is activated to generate pump light that is incident on the laser gain medium. The pump light provides energy for 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 operating temperature control conditions for the entire device. In the laser gain medium, the first seed laser and the second seed laser undergo several total reflections with different paths according to their respective incident angles and refractive indices in the gain medium, and the two power-amplified seed laser beams are emitted at the same angle through the output end face to the third laser beam output unit to realize the output of the power-amplified beams.

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