A high-power fiber seed and solid-state amplified laser preamplifier

Abstract

The application discloses a high-power optical fiber seed and solid amplification laser pre-amplifier and relates to the technical field of laser amplification, which comprises a full-polarization-maintaining optical fiber oscillator for outputting picosecond seed pulses; a full-polarization-maintaining optical fiber pre-amplifier for receiving the picosecond seed pulses, power-amplifying the picosecond seed pulses and outputting spatial light; and a solid laser amplifier comprising a first shaping lens group, a second shaping lens group, a first reflector, a pair of reflective gratings, a second reflector, a slab crystal, a first plane reflector, a first half-wave plate, a first homogenizing assembly, a first LD slab arranged in sequence on one side of the slab crystal and in a direction away from the slab crystal, and a second plane reflector, a second half-wave plate, a second homogenizing assembly and a second LD slab arranged in sequence on the other side of the slab crystal and in a direction away from the slab crystal, so that the pulse quality degradation and the pulse energy limitation problems caused by the nonlinear effect introduced by the optical fiber can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of laser amplification technology, and in particular to a high-power fiber seed and solid-state amplification laser preamplifier. Background Technology

[0002] Picosecond lasers, characterized by high average power, high beam quality, and near-diffraction limit, are widely used in precision machining, surface modification, laser cleaning, and laser marking due to their very short pulse width and high peak power. Compared to nanosecond laser processing, picosecond processing offers better control over thermal effects. Studies have shown that pulsed lasers of around 10 ps can transfer all energy to electrons within an extremely short time interval (shorter than the electron-lattice relaxation time). At this point, the electrons and the lattice have not yet reached thermal equilibrium, effectively reducing thermal diffusion and achieving "cold" processing with no thermal impact on the material. This avoids problems such as material melting, surface debris, and recast layers. Compared to femtosecond laser amplifiers, picosecond laser amplifiers offer the main advantages of relatively simple structure, low cost, and more reliable performance, making them a cost-effective choice for engineering applications. Furthermore, ultrashort pulses with high repetition rates (on the order of MHz) can improve processing efficiency and reduce unit manufacturing costs. Currently, picosecond laser amplifiers with high power, high repetition rate, and high beam quality are a hot research topic.

[0003] Compared to traditional solid-state lasers, all-fiber lasers offer advantages such as compact structure, high optical-to-optical conversion efficiency, good beam quality, and strong anti-interference capabilities. However, the small mode area and long interaction length of light propagating in optical fibers lead to pulse distortion and pulse breakage. Although chirped pulse amplification technology has achieved kilowatt-level average power and gigahertz peak power in ultrashort pulse output, this approach suffers from strong nonlinear effects in the fiber at high peak power, such as self-phase modulation and stimulated Raman scattering, limiting further increases in single-pulse energy and peak power. While large-mode-field photonic crystal fibers can significantly improve the average power of fiber lasers, the splicing of these fibers with conventional fibers can cause air hole collapse, damaging the waveguide structure and increasing splice loss. Solid-state amplification can largely circumvent the drawbacks of fiber laser amplifiers because solid-state amplifiers have a high damage threshold, can withstand high peak power, and effectively suppress nonlinear effects during amplification. However, it is undeniable that these slab amplifiers also have some disadvantages. For example, slab amplifiers require large-volume cooling systems to avoid beam quality degradation caused by thermal effects. Furthermore, to fully extract energy from the gain medium while suppressing nonlinear effects and improving pulse quality, precise control of the time domain and spectrum of femtosecond pulses is needed. Achieving steady-state output for a specific pulse state requires optimizing multiple laser parameters in a high-dimensional space. However, in complex working environments, fluctuations in laser parameters caused by environmental disturbances are difficult to adjust quickly and accurately manually, which is extremely disadvantageous for continuous production scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a high-power optical fiber seed and solid-state amplified laser preamplifier to solve the problems existing in the prior art, and to effectively avoid the pulse quality degradation and pulse energy limitation caused by the nonlinear effects introduced by the optical fiber.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a high-power fiber seed and solid-state amplification laser preamplifier, comprising a fully polarization-maintaining fiber oscillator for outputting picosecond seed pulses; a fully polarization-maintaining fiber preamplifier for receiving the picosecond seed pulses output by the fully polarization-maintaining fiber oscillator, amplifying their power, and outputting spatial light; and a solid-state laser amplifier comprising a first shaping lens group, a second shaping lens group, a first reflecting mirror, a pair of reflecting gratings, a second reflecting mirror, a slab crystal, and a first planar reflecting mirror, a first half-wave plate, a first homogenizing component, a first LD bar, and a first planar reflecting mirror, a first half-wave plate, a first homogenizing component, a first LD bar, and a first LD bar located on one side of the slab crystal and arranged sequentially away from the slab crystal. A second plane mirror, a second half-wave plate, a second homogenizing component, and a second LD bar are arranged sequentially along the direction away from the slab crystal. The pump light emitted by the first bar and the second bar is homogenized by the first homogenizing component and the second homogenizing component, and adjusted by the first half-wave plate and the second half-wave plate, respectively, before entering the slab crystal. The spatial light is shaped into an elliptical beam in the vertical direction by the first shaping lens group and then obliquely enters the slab crystal. After being amplified by the slab crystal and reflected multiple times by the first plane mirror and the second plane mirror, it is formed into a circular beam by the second shaping lens group, and then output after pulse width compression by a pair of reflection gratings and the second mirror.

[0007] Preferably, the slab crystal is welded onto a heat sink.

[0008] Preferably, the first homogenization component includes a first homogenization lens group, a first optical waveguide, and a first focusing lens group arranged sequentially along the direction away from the slab crystal, and the second homogenization component includes a second homogenization lens group, a second optical waveguide, and a second focusing lens group arranged sequentially along the direction away from the slab crystal.

[0009] Preferably, the first shaping lens group includes a first horizontal cylindrical lens, a first vertical cylindrical lens, a second horizontal cylindrical lens, and a second vertical cylindrical lens arranged at intervals, and the second shaping lens group includes a third horizontal cylindrical lens and a third vertical cylindrical lens arranged at intervals.

[0010] Preferably, it also includes a third controller and a third detector. A thermal controller is provided on the slab crystal. A pair of the reflective gratings are fixed on an electric displacement stage. The electric displacement stage can control the relative position distance between the two reflective gratings. The light beam passing through the second shaping lens group is reflected by the first partial reflector to the third detector. The light beam transmitted through the first partial reflector is directed to the pair of reflective gratings. The third controller is connected to the first bar, the second bar, the third detector, the thermal controller, and the electric displacement stage.

[0011] Preferably, the fully polarization-maintaining fiber oscillator is a fully polarization-maintaining fiber octagonal cavity oscillator that achieves mode locking based on a nonlinear amplifying ring mirror mechanism.

[0012] Preferably, the output end of the fully polarization-maintaining fiber oscillator is connected to a 1×2 first polarization-maintaining fiber coupler, the first polarization-maintaining fiber coupler is connected to a first detector, and the pump diode in the fully polarization-maintaining fiber oscillator and the first detector are both connected to the first controller.

[0013] Preferably, the all-polarization-maintaining fiber amplification device includes, in series, a polarization-maintaining fiber isolator, a first-stage pre-amplification optical path, a long-distance polarization-maintaining fiber, a second polarization-maintaining fiber coupler, a pulse selector assembly, a second-stage pre-amplification optical path, a first high-power fiber isolator, a main amplification optical path, a pump stripper, a second high-power fiber isolator, and a fiber end cap. The polarization-maintaining fiber isolator is used to receive picosecond seed pulses. Both the first-stage and second-stage amplification optical paths include a second pump diode, a polarization-maintaining fiber wavelength division multiplexer, and a polarization-maintaining gain fiber connected in series. The pulse selector assembly includes a pulse selector and an acousto-optic modulator. One end of the pulse selector and one end of the acousto-optic modulator are connected to the second polarization-maintaining fiber coupler. The other end of the pulse selector is connected to the control port of the acousto-optic modulator. The other end of the acousto-optic modulator is connected to the second-stage pre-amplification optical path. The main amplification optical path is a large-mode-area double-clad ytterbium-doped fiber driven by a combiner and a multimode pump diode.

[0014] Preferably, it further includes a second controller, a second partial reflector, and a second detector. A portion of the spatial light output from the fiber end cap is reflected by the second partial reflector to the second detector, and another portion of the spatial light is transmitted through the second partial reflector to the solid-state laser amplifier. The second controller is connected to the second pump diode in the first-stage amplification optical path, the second pump diode in the second-stage amplification optical path, the second detector, and the multimode pump diode.

[0015] Preferably, a portion of the spatial light transmitted through the second partial reflector is directed to the solid-state laser amplifier via several highly reflective mirrors.

[0016] The present invention achieves the following technical effects compared to the prior art:

[0017] This invention provides a high-power fiber seed and solid-state amplification laser preamplifier. It adopts a master oscillator power amplification design. The pulse seed source and the pre-amplifier in the system both use polarization-maintaining fiber structures. While ensuring the input power of the main amplification stage, it also makes the entire laser system more compact and stable. The main amplification stage uses a slab-type gain medium and combines direct pumping technology and crystal dual-end pumping technology to alleviate the problem of pulse quality degradation caused by thermal effects.

[0018] Meanwhile, monitoring devices are inserted into key nodes of the system to intelligently identify the pulse state. Combined with intelligent algorithms and actuators, multiple parameters of the laser amplifier are globally optimized to ensure the stability of the light source and achieve precise control to obtain high-quality pulse output. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of the high-power optical fiber seed and solid-state amplified laser preamplifier provided by the present invention;

[0021] Figure 2 A schematic diagram of a fully polarization-maintaining fiber optic oscillator;

[0022] Figure 3 A schematic diagram of the structure of a full polarization-maintaining fiber optic anti-polarization device;

[0023] Figure 4 This is a schematic diagram of a solid-state laser amplifier.

[0024] In the diagram: 100 - Fully polarization-maintaining fiber oscillator, 200 - Fully polarization-maintaining fiber amplifier, 300 - Solid-state laser amplifier;

[0025] 101-First polarization-maintaining fiber coupler; 102-First detector; 103-First controller;

[0026] 201-Polarization-maintaining fiber isolator, 202-First-stage pre-amplification optical path, 203-Long-distance polarization-maintaining fiber, 204-Second-polarization-maintaining fiber coupler, 205-Second-stage pre-amplification optical path, 206-First-stage high-power fiber isolator, 207-Main amplification optical path, 208-Pump stripper, 209-Second-stage high-power fiber isolator, 210-Fiber end cap, 211-Pulse selector, 212-Acousto-optic modulator, 213-Bundler, 214-Multimode pump diode, 215-Second controller, 216-Second partial mirror, 217-Second detector;

[0027] 301-First shaping lens group, 302-Slab crystal, 303-First plane mirror, 304-First half-wave plate, 305-First LD bar, 306-Second plane mirror, 307-Second half-wave plate, 308-Second LD bar, 309-First homogenizing lens group, 310-First optical waveguide, 311-First focusing lens group, 312-Second homogenizing lens group, 313-Second optical waveguide, 314-Second focusing lens group, 315-Second shaping lens group, 316-First mirror, 317-Reflection grating, 318-Second mirror, 319-Third controller, 320-Third detector. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a high-power optical fiber seed and solid-state amplified laser preamplifier to solve the problems existing in the prior art, and to effectively avoid the pulse quality degradation and pulse energy limitation caused by the nonlinear effects introduced by the optical fiber.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This invention provides a high-power fiber seed and a solid-state amplified laser preamplifier, such as... Figure 1 As shown, the high-power fiber seed and solid-state amplified laser preamplifier includes:

[0032] The fully polarization-maintaining fiber optic oscillator 100 is used to output low-energy picosecond seed pulses.

[0033] Specifically, such as Figure 2As shown, the fully polarization-maintaining fiber oscillator 100 is a fully polarization-maintaining fiber nine-cavity oscillator that achieves mode-locking based on a nonlinear amplifying ring mirror mechanism. The output end of the fully polarization-maintaining fiber oscillator 100 is connected to a 1×2 first polarization-maintaining fiber coupler 101. The first polarization-maintaining fiber coupler 101 is connected to a first detector 102. The pump diode and the first detector 102 in the fully polarization-maintaining fiber oscillator 100 are both connected to a first controller 103. 99% of the energy output by the first polarization-maintaining fiber coupler 101 is output as a picosecond seed pulse, and 1% of the energy is received by the first detector 102 to obtain the spectral shape and pulse shape. The relevant information is received by the first controller 103 and processed according to the set program. Then, the output power of the pump diode is controlled, thereby changing the output state of the fully polarization-maintaining fiber oscillator 100.

[0034] The polarization-maintaining fiber optic amplifier 200 is used to receive the picosecond seed pulse output by the polarization-maintaining fiber oscillator 100, provide sufficient single-pulse energy to the solid-state laser amplifier 300, amplify its power, and output spatial light.

[0035] Specifically, such as Figure 3As shown, the all-polarization-maintaining fiber amplifier 200 includes a second controller 215, a second partial reflector 216, a second detector 217, a polarization-maintaining fiber isolator 201 connected in series, a first-stage pre-amplification optical path 202, a long-distance polarization-maintaining fiber 203, a second polarization-maintaining fiber coupler 204, a pulse selection component, a second-stage pre-amplification optical path 205, a first high-power fiber isolator 206, a main amplification optical path 207, a pump stripper 208, a second high-power fiber isolator 209, and an 8° angle fiber end cap 210. The polarization-maintaining fiber isolator 201 prevents back-reflected light from affecting the preceding optical path; the first-stage pre-amplification optical path 202 amplifies seed light from a few milliwatts to the hundreds of milliwatts level; the long-distance polarization-maintaining fiber 203 is used to broaden the pulse, preventing excessive nonlinear effects introduced during the final pre-amplification stage due to excessively short pulse width, which would affect the output pulse quality; the second-stage amplification optical path aims to compensate for pulse broadening and select the pulse selection component. The power loss caused during the process; the polarization-maintaining fiber isolator 201 is used to receive picosecond seed pulses. Both the first-stage amplification optical path and the second-stage amplification optical path include a second pump diode, a polarization-maintaining fiber wavelength division multiplexer, and a polarization-maintaining gain fiber connected in series; the pulse selection component includes a pulse selector 211 and an acousto-optic modulator 212. One end of the pulse selector 211 and one end of the acousto-optic modulator 212 are connected to the second polarization-maintaining fiber coupler 204. The other end of the pulse selector 211 is connected to the control port of the acousto-optic modulator 212. The other end of the acousto-optic modulator 212 is connected to the second-stage pre-amplification optical path 205. The broadened pulse is then divided into two parts by the second polarization-maintaining fiber coupler 204. 10% of the pulse is used as the trigger signal of the pulse selector 211 to control the periodic on and off of the acousto-optic modulator 212, thereby achieving precise control of the number of pulses or the repetition frequency. The selected pulse enters the second-stage amplification optical path after passing through the fiber isolator.

[0036] More specifically, the main amplification optical path 207 is a large-mode-area double-clad ytterbium-doped fiber driven by a combiner 213 and a multimode pump diode 214. Part of the spatial light output from the fiber end cap 210 is reflected by a second part of the reflector 216 to a second detector 217, and another part of the spatial light is transmitted through the second part of the reflector 216 and several high-reflection mirrors to a solid-state laser amplifier 300. The second controller 215 is connected to the second pump diode in the first-stage amplification optical path, the second pump diode in the second-stage amplification optical path, the second detector 217, and the multimode pump diode. The spectral shape and pulse shape data obtained by the second detector 217 are transmitted to the second controller 215. After processing, the control information is sent to the pump diodes in the first-stage amplification optical path, the second-stage amplification optical path, and the main amplification optical path 207 to control their pump current, thereby controlling the nonlinear effects in the fiber link in each amplification stage, thus predicting the pulse evolution and spectral evolution process, and obtaining a high-energy pulse that meets the requirements of subsequent amplification.

[0037] Solid-state laser amplifier 300, such as Figure 4 As shown, the solid-state laser amplifier 300 includes a first shaping lens group 301, a second shaping lens group 315, a first reflecting mirror 316, a pair of reflecting gratings 317, a second reflecting mirror 318, a third controller 319, a third detector 320, a slab crystal 302 welded to a heat sink, and a first plane reflecting mirror 303, a first half-wave plate 304, a first homogenizing component, and a first LD bar 305 arranged sequentially on one side of the slab crystal 302 and in a direction away from the slab crystal 302, and a second plane reflecting mirror 306, a second half-wave plate 307, a second homogenizing component, and a second LD bar 308 arranged sequentially on the other side of the slab crystal 302 and in a direction away from the slab crystal 302. The slab crystal 302 is... Welding to the heat sink reduces the thermal effect; the first plane mirror 303 and the second plane mirror 306 are used to reflect the incident light so that it passes through the gain medium (slab crystal 302) multiple times to fully extract energy; since the neodymium-doped yttrium vanadate crystal has a birefringence effect, the first half-wave plate 304 and the second half-wave plate 307 are needed to adjust the polarization state of the pump light so that it is aligned with the C-axis of the slab crystal 302 to achieve good mode matching; in order to make the pump light emitted by the first LD bar 305 and the second LD bar 308 have uniform light intensity in the horizontal direction, the system uses a double-sided antireflection coated optical waveguide to homogenize it, and the lens group (LENS) between the optical waveguide and the LD bar and the waveplate is used to focus and homogenize the beam.

[0038] The pump light emitted by the first and second bars is homogenized by the first and second homogenizing components, respectively, and adjusted by the first half-wave plate 304 and the second half-wave plate 307, respectively, before entering the slab crystal 302. The spatial light is shaped into an elliptical beam in the vertical direction by the first shaping lens group 301 and then obliquely enters the slab crystal 302. After being amplified by the slab crystal 302 and reflected multiple times by the first plane mirror 303 and the second plane mirror 306, it is formed into a circular beam by the second shaping mirror group, and then output after pulse width compression by a pair of reflection gratings 317 and the second reflection mirror 318.

[0039] Specifically, the first homogenizing component includes a first homogenizing lens group 309, a first optical waveguide 310, and a first focusing lens group 311 arranged sequentially along the direction away from the slab crystal 302; the second homogenizing component includes a second homogenizing lens group 312, a second optical waveguide 313, and a second focusing lens group 314 arranged sequentially along the direction away from the slab crystal 302; the first shaping lens group 301 includes a first horizontal cylindrical lens, a first vertical cylindrical lens, a second horizontal cylindrical lens, and a second vertical cylindrical lens arranged sequentially at intervals; and the second shaping lens group 315 includes a third horizontal cylindrical lens and a third vertical cylindrical lens arranged at intervals.

[0040] More specifically, a thermal controller is provided on the slab crystal 302, and a pair of reflective gratings 317 are fixed on an electric displacement stage. The electric displacement stage can control the relative position distance between the two reflective gratings 317. The light beam passing through the second shaping lens group 315 is reflected by the first partial reflector to the third detector 320. The light beam transmitted through the first partial reflector is directed to the pair of reflective gratings 317. The third controller 319 is connected to the first bar, the second bar, the third detector 320, the thermal controller, and the electric displacement stage. The third controller 319 can receive the spectral shape and pulse shape received by the third detector 320 at any time, and then control the current of the LD and the grating spacing through the algorithm of the third controller 319 to obtain the optimal system output.

[0041] The aforementioned high-power fiber seed and solid-state amplified laser preamplifier employs a master oscillator power amplification design. Both the pulse seed source and the preamplifier utilize polarization-maintaining fiber structures, ensuring sufficient input power for the main amplification stage while making the entire laser system more compact and stable. The main amplification stage uses a slab-type gain medium, combined with direct pumping and crystal dual-end pumping techniques to mitigate pulse quality degradation caused by thermal effects. Simultaneously, monitoring devices are inserted at key nodes in the system to intelligently identify pulse states. Combined with intelligent algorithms and actuators, multiple parameters of the laser amplifier are globally optimized, ensuring the stability of the light source and achieving precise control to obtain high-quality pulse output.

[0042] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A high power fiber seed and solid state amplified laser pre-amplifier characterized by: include: A fully polarization-maintaining fiber oscillator, which is used to output picosecond seed pulses; A fully polarization-maintaining fiber preamplifier is used to receive the picosecond seed pulse output by the fully polarization-maintaining fiber oscillator, amplify its power, and output spatial light. A solid-state laser amplifier includes a first shaping lens group, a second shaping lens group, a first reflecting mirror, a pair of reflecting gratings, a second reflecting mirror, a slab crystal, and a first plane reflecting mirror, a first half-wave plate, a first homogenizing component, and a first bar arranged sequentially on one side of the slab crystal away from the slab crystal. A second plane reflecting mirror, a second half-wave plate, a second homogenizing component, and a second bar are arranged sequentially on the other side of the slab crystal away from the slab crystal. Pump light emitted from the first bar and the second bar is homogenized by the first and second homogenizing components, and adjusted by the first and second half-wave plates, respectively, before entering the slab crystal. Spatial light, after being shaped by the first shaping lens group into an elliptical beam in the vertical direction, obliquely enters the slab crystal. After gaining through the slab crystal and multiple reflections by the first and second plane reflecting mirrors, it passes through the second shaping lens group to form a circular beam, which is then pulse-width compressed by the pair of reflecting gratings and the second reflecting mirror before being output.

2. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: The lath crystals are welded onto a heat sink.

3. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: The first homogenization component includes a first homogenization lens group, a first optical waveguide, and a first focusing lens group arranged sequentially along the direction away from the slab crystal. The second homogenization component includes a second homogenization lens group, a second optical waveguide, and a second focusing lens group arranged sequentially along the direction away from the slab crystal.

4. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: The first shaping lens group includes a first horizontal cylindrical lens, a first vertical cylindrical lens, a second horizontal cylindrical lens, and a second vertical cylindrical lens arranged at intervals in sequence. The second shaping lens group includes a third horizontal cylindrical lens and a third vertical cylindrical lens arranged at intervals in sequence.

5. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: It also includes a third controller and a third detector. A thermal controller is provided on the slab crystal. A pair of the reflective gratings are fixed on an electric displacement stage. The electric displacement stage can control the relative position distance between the two reflective gratings. The light beam passing through the second shaping lens group is reflected by the first partial reflector to the third detector. The light beam transmitted through the first partial reflector is directed to the pair of reflective gratings. The third controller is connected to the first bar, the second bar, the third detector, the thermal controller, and the electric displacement stage.

6. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: The fully polarization-maintaining fiber oscillator is a fully polarization-maintaining fiber octagonal oscillator that achieves mode-locking based on a nonlinear amplifying ring mirror mechanism.

7. The high power fiber seed and solid state power amplified laser preamplifier of claim 6, wherein: The output of the fully polarization-maintaining fiber oscillator is connected to a 1×2 first polarization-maintaining fiber coupler, which is connected to a first detector. The pump diode in the fully polarization-maintaining fiber oscillator and the first detector are both connected to a first controller.

8. The high power fiber seed and solid state amplified laser pre-amplifier of claim 1, wherein: The full polarization maintaining fiber prevents large devices including polarization maintaining fiber isolator, first-stage pre-amplification optical path, long-distance polarization maintaining fiber, second polarization maintaining fiber coupler, pulse selection assembly, second-stage pre-amplification optical path, first high-power fiber isolator, main amplification optical path, pump stripper, second high-power fiber isolator and fiber end cap in sequence, the polarization maintaining fiber isolator is used for receiving picosecond seed pulses, the first-stage pre-amplification optical path and the second-stage pre-amplification optical path both include second pump diode, polarization maintaining fiber wavelength division multiplexer and polarization maintaining gain optical fiber in series, the pulse selection assembly includes pulse selector and acousto-optic modulator, one end of the pulse selector and one end of the acousto-optic modulator are both connected with the second polarization maintaining fiber coupler, the other end of the pulse selector is connected with the control port of the acousto-optic modulator, the other end of the acousto-optic modulator is connected with the second-stage pre-amplification optical path, and the main amplification optical path is a large-mode-area double-clad ytterbium-doped fiber driven by a beam combiner and a multimode pump diode.

9. The high power fiber seed and solid state power amplified laser preamplifier of claim 8, wherein: The second controller, the second partial reflector and the second detector are also included, a part of the spatial light output by the fiber end cap is reflected to the second detector through the second partial reflector, another part of the spatial light is transmitted to the solid laser amplifier through the second partial reflector, and the second controller is connected with the second pump diode of the first-stage pre-amplification optical path, the second pump diode in the second-stage pre-amplification optical path, the second detector and the multimode pump diode.

10. The high power fiber seed and solid state amplified laser pre-amplifier of claim 9, wherein: The part of the spatial light transmitted by the second partial reflector is reflected to the solid laser amplifier through several high-reflective mirrors.

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