CN216450928U

CN216450928U - High-power long-wave infrared ultrafast laser system with adjustable wavelength

Info

Publication number: CN216450928U
Application number: CN202122807832.2U
Authority: CN
Inventors: 闫培光; 李博文; 林海枫; 王天武; 杨俊波
Original assignee: Shenzhen University
Current assignee: Shenzhen University
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2022-05-06
Anticipated expiration: 2031-11-16

Abstract

The utility model is suitable for the technical field of laser, and provides a high-power long-wave infrared ultrafast laser system with adjustable wavelength. The ultrafast laser system includes: the first laser structure is used for generating a laser beam and outputting the laser beam after the wave band of the laser beam is processed to be within a first wave band range; the second laser structure is arranged adjacent to the first laser structure and used for acquiring the laser beam output by the first laser structure and converting the wave band of the laser beam from the first wave band range to be positioned in the second wave band range; the laser beam propagates in the first laser structure in a direction opposite to that of the second laser structure. According to the utility model, the high-power long-wave infrared ultrafast laser system has a compact integral structure, is convenient to build, has a simple light path structure, can reliably realize stable output of high-power long-wave infrared ultrafast laser through the processing and conversion of the first laser structure and the second laser structure, and well meets the use requirements.

Description

High-power long-wave infrared ultrafast laser system with adjustable wavelength

Technical Field

The utility model belongs to the technical field of laser, and particularly relates to a high-power long-wave infrared ultrafast laser system with adjustable wavelength.

Background

The long-wave infrared spectrum with the wavelength of 8-12 microns is positioned in a transparent window of the atmosphere, and has important application in the fields of radar, measurement and control, remote sensing monitoring and the like. In addition, the wave band covers characteristic absorption lines of many atoms and molecules, which are called fingerprint spectral regions of the molecules. Therefore, the high-power long-wave infrared ultrashort pulse laser with tunable wavelength is also used for toxic gas detection, molecular spectrum analysis, medical diagnosis and the like. In recent years, the development of the medium-wavelength infrared laser obtained by utilizing the nonlinear frequency conversion technology is rapid, but the preparation level of the high-power long-wave infrared nonlinear crystal and the related laser technology are limited, at present, the generation of the medium-wave infrared laser with the wavelength of 3-5 microns is mainly limited, and the research on the high-power long-wave infrared with the wavelength of 8-12 microns is slow. Therefore, a method for obtaining high-power long-wave infrared by using diamond crystals based on the stimulated Raman scattering principle is developed. Wherein the Raman frequency shift of diamond is up to 1332cm^-1The crystal has the highest Raman frequency shift known at present, has an extremely wide spectrum transmission range above 227nm, and has thermal conductivity more than 150 times that of common solid laser crystal YAG.

At present, the quasi-continuous or continuous laser pumping diamond crystal is mainly used to obtain longer wavelength Raman laser output at home and abroad based on an Optical Parametric Oscillation (OPO) structure. However, the laser system has a complex overall structure, is easily interfered by the environment, and cannot obtain long-term stable pulse output.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present invention provides a high-power long-wave infrared ultrafast laser system with adjustable wavelength, so as to solve the problems that the laser system has a complex overall structure, is easily interfered by the environment, and cannot obtain a long-term stable pulse output.

In order to solve the above problems, the technical solution of the embodiment of the present invention is implemented as follows:

a high-power long-wave infrared ultrafast laser system with adjustable wavelength is used for generating laser with a wave band of 8-12 microns and comprises: the first laser structure is used for generating laser beams and outputting the laser beams after the wave bands of the laser beams are processed to be within a first wave band range; the second laser structure is arranged adjacent to the first laser structure and used for acquiring the laser beam output by the first laser structure and converting the wave band of the laser beam from the first wave band range to a second wave band range; wherein the laser beam propagates in the first laser structure in a direction opposite to that of the second laser structure, and the wavelength in the first wavelength band is smaller than the wavelength in the second wavelength band.

In some embodiments, the first laser structure comprises: the pumping source is used for generating a pumping light beam and transmitting the pumping light beam along a first light path; the first optical path adjusting component is arranged adjacent to the pumping source and is used for adjusting the propagation height and the path of the incident pumping beam so as to enable the pumping beam to propagate along a second optical path; the first lens is arranged in front of the first optical path adjusting component along the propagation direction of the second optical path and is used for focusing the incident pump light beam; the nonlinear crystal is arranged in front of the first lens along the propagation direction of the second optical path and is used for adjusting the wave band of the incident pump beam so as to obtain a laser beam; the second optical path adjusting component is arranged in front of the nonlinear crystal along the propagation direction of the second optical path and is used for adjusting the laser beam to propagate along a third optical path so as to be injected into the second laser structure; the first optical path and the second optical path have the same propagation direction, and the second optical path and the third optical path have opposite propagation directions.

In some embodiments, the first optical path adjusting member comprises: the two first reflectors are arranged oppositely and obliquely at intervals and used for converting the propagation route of the laser beam from the first light path to the second light path.

In some embodiments, two of the first reflective mirrors are parallel to each other.

In some embodiments, the second light path adjusting member comprises: and the two second reflecting mirrors are arranged oppositely and obliquely at intervals and used for converting the propagation route of the laser beam into the third light path from the second light path.

In some embodiments, the first laser structure further comprises: and the second lens is arranged between the nonlinear crystal and the second light path adjusting component and is used for receiving the laser beam emitted by the nonlinear crystal and collimating the laser beam.

In some embodiments, the first laser structure further comprises: and the filter is arranged between the second lens and the second light path adjusting component and used for filtering residual signal light in the laser beam.

In some embodiments, the propagation directions of the first, second and third optical paths are all parallel to each other.

In some embodiments, the second laser structure comprises: the polarization controller is arranged at the incident end of the third optical path and is used for controlling the external polarization state of the incident laser beam; the third lens is arranged in front of the polarization controller along the propagation direction of the third optical path and is used for focusing the incident laser beam; the Raman crystal is arranged in front of the third lens along the propagation direction of the third optical path and is used for adjusting the wave band of the incident laser beam; and the fourth lens is arranged at the emergent end of the third optical path adjacent to the Raman crystal and is used for receiving the laser beam emitted from the Raman crystal and collimating the laser beam.

In some embodiments, the polarization controller includes a beam splitting prism and a half-wave plate disposed in front of the beam splitting prism along the propagation direction of the third optical path.

The embodiment of the utility model provides a high-power long-wave infrared ultrafast laser system with adjustable wavelength, which comprises a first laser structure and a second laser structure, wherein the first laser structure is used for outputting a laser beam positioned in a first wave band range, and the second laser structure is used for receiving the laser beam output by the first laser structure, converting the wave band of the laser beam into a second wave band range and outputting the second wave band range. According to the arrangement, the high-power long-wave infrared ultrafast laser system with the adjustable wavelength is compact in overall structure, convenient to build, simple in light path structure, and capable of reliably achieving stable output of high-power long-wave infrared ultrafast laser through processing and conversion of the first laser structure and the second laser structure, and well meets use requirements.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a wavelength-tunable high-power long-wave infrared ultrafast laser system provided in an embodiment of the present invention.

Description of reference numerals:

11. a first laser structure; 111. a pump source; 112. a first optical path adjusting member; 1121. a first reflective mirror; 113. a first lens; 114. a nonlinear crystal; 115. a second optical path adjusting member; 1151. a second reflective mirror; 116. a second lens; 117. a filter plate; 12. a second laser structure; 121. a polarization controller; 1211. a beam splitter prism; 1212. a half-wave plate; 122. a third lens; 123. a Raman crystal; 124. a fourth lens; 13. a first optical path; 14. a second optical path; 15. and a third light path.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

The individual features described in the embodiments can be combined in any suitable manner without departing from the scope, for example different embodiments and aspects can be formed by combining different features. In order to avoid unnecessary repetition, various possible combinations of the specific features of the utility model will not be described further.

It should be noted that the terms of orientation such as left, right, up and down in the embodiments of the present invention are only relative to each other or are referred to the normal use state of the product, and should not be considered as limiting.

As shown in fig. 1, the high-power long-wave infrared ultrafast laser system with adjustable wavelength provided by the embodiment of the utility model is used for generating high-power ultrafast laser with adjustable wavelength of 8-12 μm, and the light type of the laser can be infrared laser. Of course, other types of light lasers are possible. The high-power long-wave infrared ultrafast laser system with adjustable wavelength comprises a first laser structure 11 and a second laser structure 12. The first laser structure 11 is used for generating a laser beam, and can process the wavelength band of the laser beam to be within a first wavelength band and then output the laser beam. The second laser structure 12 is disposed adjacent to the first laser structure 11, and the second laser structure 12 is configured to obtain the laser beam output by the first laser structure 11, and convert a wavelength band of the laser beam from a first wavelength band range to a second wavelength band range, where a wavelength in the first wavelength band range is smaller than a wavelength in the second wavelength band range. Specifically, the positions of the first laser structure 11 and the second laser structure 12 are arranged, so that the propagation direction of the laser beam in the first laser structure 11 is opposite to the propagation direction in the second laser structure 12, that is, the first laser structure 11 and the second laser structure 12 are arranged side by side, the propagation requirements of the laser beam can be met, and the whole laser structure is not required to be arranged in a linear distribution manner, so that the compactness of the whole structure is realized, and the miniaturization of the whole system is facilitated.

In the embodiment of the present invention, the first laser structure 11 is configured to generate a laser beam, and the laser beam can obtain laser in a first wavelength range, specifically, laser in a middle-wave infrared band with a tunable wavelength of 3.9 to 4.7 μm, after being optically processed by the internal structure in the internal propagation process of the first laser structure 11. And the second laser structure 12 can perform optical processing on the laser beam again after receiving the laser beam output from the first laser structure 11, so as to obtain laser within a second waveband, specifically, laser within a long-wave infrared waveband of 8-12 μm. In this way, after the processing of the first laser structure 11 and the second laser structure 12, a laser capable of meeting the use requirements is obtained. Specifically, the arrangement of the high-power long-wave infrared ultrafast laser system with the adjustable wavelength can tightly regulate and control the temperature in the process of generating laser beams, overcome environmental interference, realize the output of the laser beams meeting the requirements, and also can adjust the size of a focusing light spot and the position of optical treatment inside the focusing light spot, thereby improving the conversion efficiency and the output power of long-wave infrared lasers and realizing the stable output of the high-power long-wave infrared ultrafast lasers. Meanwhile, the high-power long-wave infrared ultrafast laser system with the adjustable wavelength has the advantages of compact integral structure, convenience in construction and simple light path structure, and well meets the use requirements.

As shown in fig. 1, in some embodiments, the first laser structure 11 includes a pump source 111, a first optical path adjustment component 112, a first lens 113, a nonlinear crystal 114, and a second optical path adjustment component 115. The pump source 111 is used to generate a pump beam and propagate the pump beam along the first optical path 13. The first optical path adjusting component 112 is disposed adjacent to the pump source 111, and the first optical path adjusting component 112 is used for adjusting the propagation height and route of the incident pump beam so that the pump beam propagates along the second optical path 14. The first lens 113 is disposed in front of the first optical path adjusting assembly 112 along the propagation direction of the second optical path 14, and the first lens 113 is used for focusing the incident pump beam. A nonlinear crystal 114 is disposed in front of the first lens 113 along the propagation direction of the second optical path 14, and the nonlinear crystal 114 is used for adjusting the wavelength band of the incident pump beam to obtain a laser beam. A second optical path adjustment assembly 115 is disposed in front of the nonlinear crystal 114 along the propagation direction of the second optical path 14, and the second optical path adjustment assembly 115 is used for adjusting the laser beam to propagate along the third optical path 15 to be injected into the second laser structure 12. The first optical path 13 and the second optical path 14 travel in the same direction, and the second optical path 14 and the third optical path 15 travel in opposite directions. Specifically, the pump source 111 is a high-power femtosecond fiber laser, the working center wavelength is 1035nm, the pulse width is fs magnitude, and the pulse repetition frequency is KHz-GHz magnitude. The pump light beam generated by the pump source 111 propagates towards the first light path 13, the first light path adjusting component 112 is disposed in front of the first light path 13, the first light path adjusting component 112 has high reflectivity, and after receiving the pump light beam, the first light path adjusting component 112 adjusts the propagation direction of the pump light beam, adjusts the height and direction of the pump light beam, and converts the pump light beam to propagate towards the second light path 14. The first lens 113 is a K9(K9 is a specification model of a lens) plano-convex lens, and is used for focusing a pump beam and realizing pump beam spatial mode matching. The nonlinear crystal 114 is a Periodically Poled Lithium Niobate (PPLN) crystal, and is precisely temperature-controlled by a high-precision temperature control module. The laser beam emitted from the nonlinear crystal 114 enters the second optical path adjusting component 115, and is reflected by the second optical path adjusting component 115 to propagate from the second optical path 14 to the third optical path 15. The first laser structure 11 is configured such that the pump source 111 generates a laser beam, the laser beam is adjusted by the first optical path 13 adjustment component and emitted into the first lens 113, the first lens 113 focuses the pump beam in the nonlinear crystal 114, spontaneous parametric down-conversion occurs in the nonlinear crystal 114 due to its high peak power, and the wavelength of the laser beam can be adjusted by adjusting the inversion period and the corresponding operating temperature of the nonlinear crystal 114. The intermediate-wave infrared laser with tunable wavelength of 3.9-4.7 mu m is obtained in the embodiment of the utility model. By increasing the average power of the pump source 111, a high-power medium wave infrared laser is correspondingly generated, and then the spatial optical path is adjusted by the optical path adjusting component to be used as the pump light of the subsequent raman conversion.

In the embodiment of the present invention shown in fig. 1, the pump beam generated by the pump source 111 propagates along the first optical path 13, and then propagates along the second optical path 14 by setting the first optical path adjusting component 112 to perform reflection conversion of the optical path, and the propagation direction of the second optical path 14 is the same as the propagation direction of the first optical path 13. Thus, the original propagation direction of the optical path is kept, and the height of the pumping light is adjusted. Meanwhile, the second light path adjusting component 115 is arranged to convert the propagation direction of the laser beam reflected by the second light path 14 into the third light path 15 propagating in the opposite direction. Therefore, the internal parts of the whole laser system do not need to be distributed along the same straight line, so that the size range of the internal structure on the straight line distribution is reduced, and the integral compactness of the internal structure is facilitated.

As shown in fig. 1, in some embodiments, the first optical path adjustment assembly 112 includes a first reflective mirror 1121. The first reflective mirrors 1121 are disposed in two numbers, and the two first reflective mirrors 1121 are disposed in an opposing and inclined manner. Two first mirrors 1121 are used to convert the propagation path of the pump beam from the first optical path 13 to the second optical path 14. Optionally, the first reflective mirror 1121 adopts a silver mirror, and has a reflectivity of more than 97% for the pump beam in the 1035nm wavelength band, so that the function of adjusting the height and direction of the pump beam can be reliably implemented.

As shown in fig. 1, in the embodiment of the present invention, two first reflective mirrors 1121 are arranged in parallel to each other, and the inclination angles are set to 45 °. In this way, the second optical path 14 and the first optical path 13 can be obtained while remaining parallel to each other. Of course, in other embodiments, the two first reflective mirrors 1121 may be disposed in other manners according to the usage requirement, such as being disposed in non-parallel to each other or being tilted to other angles and the tilted angles of the two first reflective mirrors being different, and the flexibility of the disposition is good so as to enable the pump beam to propagate toward different directions.

As shown in fig. 1, in some embodiments, the second optical path adjustment assembly 115 includes a second reflective mirror 1151. The second reflective mirror 1151 is provided with two, and the two second reflective mirrors 1151 are arranged to be opposite to each other at an interval and inclined, and the two second reflective mirrors 1151 are used for converting the propagation path of the laser beam from the second optical path 14 to the third optical path 15. Optionally, the second reflective mirror 1151 is a gold mirror, the reflectivity of the laser beam in a 2-5 μm waveband is greater than 97%, and the effect of adjusting the propagation height and direction of the laser beam can be reliably implemented.

As shown in fig. 1, in the embodiment of the present invention, it is also adopted to arrange two second reflective mirrors 1151 in parallel with each other and to set the inclination angles to 45 ° each. In this way, the third light path 15 and the second light path 14 can be obtained while remaining parallel to each other. Of course, in other embodiments, according to the usage requirement, the two second reflective mirrors 1151 may also be disposed in other manners, such as being not parallel to each other or being tilted to another angle, and the tilted angles of the two second reflective mirrors being different, so that the laser beams with different propagation directions can be obtained.

As shown in fig. 1, in some embodiments, the first laser structure 11 further comprises a second lens 116. The second lens 116 is disposed between the nonlinear crystal 114 and the second optical path adjusting member 115. The second lens 116 is used for receiving the laser beam incident through the nonlinear crystal 114 and collimating the laser beam. Optionally, the second lens 116 is a calcium fluoride mid-infrared achromatic lens for collimating mid-wave infrared generated by spontaneous parametric down-conversion to obtain a laser beam meeting the use requirement.

As shown in fig. 1, in some embodiments, the first laser structure 11 further comprises a filter 117. A filter 117 is disposed between the second lens 116 and the second optical path adjusting member 115, and the filter 117 is used for filtering residual signal light in the incident laser beam. Specifically, the filter 117 is a 2.4 μm long pass filter 117, and is used to filter out residual pump light and 1.5 μm signal light generated accompanying spontaneous parametric down-conversion, so as to obtain a laser beam meeting the use requirement.

As shown in fig. 1, in the embodiment of the present invention, the propagation directions of the first light path 13, the second light path 14, and the third light path 15 are optionally all set to be parallel to each other.

As shown in fig. 1, in some embodiments, the second laser structure 12 includes a polarization controller 121, a third lens 122, a raman crystal 123, and a fourth lens 124. A polarization controller 121 is disposed at the incident end of the third optical path 15, and the polarization controller 121 is configured to control the external polarization state of the incident laser beam. The third lens 122 is disposed in front of the polarization controller 121 along the propagation direction of the third optical path 15, and the third lens 122 is used for focusing the incident laser beam. The raman crystal 123 is disposed in front of the third lens 122 along the propagation direction of the third optical path 15, and the raman crystal 123 is used to adjust the wavelength band of the incident laser beam. The fourth lens 124 is disposed adjacent to the raman crystal 123 at the exit end of the third optical path 15, and the fourth lens 124 is configured to receive the laser beam emitted from the raman crystal 123 and collimate the laser beam. Specifically, the polarization state of the mid-wave infrared is controlled by the polarization controller 121 so that the polarization direction thereof is along the crystal axis direction of the diamond <111> plane to obtain the maximum raman gain. The third lens 122 is a calcium fluoride mid-infrared lens, and is used for focusing 3.9-4.7 μm mid-wave infrared laser on the center of the raman crystal 123. The Raman crystal 123 is a single crystal diamond crystal, and is refrigerated through a TEC refrigeration module, so that the crystal is kept at 18 ℃. The fourth lens 124 is a collimating lens, optionally a calcium fluoride mid-infrared lens, for collimating the generated long-wavelength raman laser. Because the diamond Raman frequency shift is 1332cm-1, the required wavelength of 8-12 μm long-wave infrared laser after Raman is calculated according to Vvib ═ 1/λ pump-1/λ stokes. By adopting such an arrangement, diamond is used as the raman crystal 123, self-phase matching is enabled, and raman gain is independent of the directions of the pump light and the output beam, so that high-luminance laser output can be obtained even in the case of pumping with low beam quality, and multi-beam non-collinear raman beam combining becomes possible.

As shown in fig. 1, in the embodiment of the present invention, the polarization controller 121 includes a beam splitting prism 1211 and a half-wave plate 1212, and the half-wave plate 1212 is disposed in front of the beam splitting prism 1211 along the propagation direction of the third optical path 15. The combination of the beam splitter 1211 and the half-wave plate 1212 can adjust the polarization direction of the medium-wave infrared laser light to be parallel to the crystal axis direction of the 123<111> plane of the raman crystal, thereby obtaining the maximum raman gain.

According to the high-power long-wave infrared ultrafast laser system with adjustable wavelength, the femtosecond-assisted high-power pumping source 111 is arranged, a single-channel pumping structure is adopted, a complex optical path structure is omitted, the nonlinear crystal 114 can be subjected to waveguide structure design subsequently, full optical fiber of the whole system is expected to be achieved, integration and miniaturization of medium-wave infrared and long-wave infrared light sources are further achieved, and application of the system in more occasions is expanded. Meanwhile, by means of a focusing lens with a proper focal length and a five-dimensional high-precision adjusting translation table carrying the nonlinear crystal 114, the conversion efficiency and the output power of the long-wave infrared laser are improved by adjusting the size of a focusing light spot and the position of the focusing light spot at the center of the crystal, stable laser output can be obtained, and the use requirement is well met.

The specific operation of the high-power long-wave infrared ultrafast laser system with adjustable wavelength provided by the embodiment of the utility model is as follows:

the center wavelength of a commercial high-power femtosecond ultrafast pump source 111 is 1030nm, the emission pulse width is 500fs, the repetition frequency is 250KHz, the maximum average power is 20W, and the corresponding peak power is up to 160 MW. And performing optical path collimation on the pump beam through the two first reflectors 1121 under low power, and adjusting the height and direction of the optical path. The pump beam is focused in the PPLN nonlinear crystal 114 through the first lens 113, the nonlinear crystal 114 is carried on the high-precision temperature control module, and the temperature control module is fixed through the high-precision five-dimensional adjusting platform and is used for optimizing the position of the pump beam focusing spot in the nonlinear crystal 114, so that mode matching is realized. By tuning the reverse period of the nonlinear crystal 114 and the corresponding phase matching temperature, the wavelength tunable medium wave infrared output is realized in the nonlinear spontaneous parameter down-conversion process, and the pure medium wave band infrared laser beam output is realized by combining the medium infrared achromatic color of the second lens 116 and the 2.4 mu m long pass filter 117. In this example, the wavelength was 3.9-4.7 μm as measured by Fourier spectroscopy.

The obtained medium-wave infrared laser beam is reflected and converted by the two second reflectors 1151, so that the spatial light path is convenient to adjust, and the medium-wave infrared laser beam is used for pumping light of subsequent Raman. Then, the polarization direction of the medium wave infrared laser is adjusted through the beam splitter 1211 and the half-wave plate 1212, so that the polarization direction of the medium wave infrared laser is along the crystal axis direction of the 123<111> plane of the single crystal diamond Raman crystal, and the maximum Raman gain is realized. The middle infrared achromatic color of the third lens 122 focuses the middle wave infrared laser beam in the single crystal diamond Raman crystal 123, and due to the self-phase matching advantage, the position of the focused beam and the working temperature of the Raman crystal 123 do not need to be accurately adjusted, so that the optical path optimization adjustment in the nonlinear frequency conversion process is simplified. In this example, long-wavelength infrared laser light having a wavelength of 8 to 12 μm is generated. The high-power medium wave infrared output with adjustable wavelength is realized by increasing the average power of the pumping source 111 and adjusting the inversion period and the corresponding phase matching temperature of the PPLN nonlinear crystal 114, and the high-power and wavelength-tunable characteristics of long wave infrared are further realized by the Raman crystal 123.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A high-power long-wave infrared ultrafast laser system with adjustable wavelength is used for generating laser with a wave band of 8-12 microns and is characterized by comprising the following components in parts by weight:

the first laser structure is used for generating laser beams and outputting the laser beams after the wave bands of the laser beams are processed to be within a first wave band range;

the second laser structure is arranged adjacent to the first laser structure and used for acquiring the laser beam output by the first laser structure and converting the wave band of the laser beam from the first wave band range to a second wave band range;

wherein the laser beam propagates in the first laser structure in a direction opposite to that of the second laser structure, and the wavelength in the first wavelength band is smaller than the wavelength in the second wavelength band.

2. The wavelength tunable high power long wave infrared ultrafast laser system of claim 1, wherein said first laser structure comprises:

the pumping source is used for generating a pumping light beam and transmitting the pumping light beam along a first light path;

the first optical path adjusting component is arranged adjacent to the pumping source and is used for adjusting the propagation height and the path of the incident pumping beam so as to enable the pumping beam to propagate along a second optical path;

the first lens is arranged in front of the first optical path adjusting component along the propagation direction of the second optical path and is used for focusing the incident pump light beam;

the nonlinear crystal is arranged in front of the first lens along the propagation direction of the second optical path and is used for adjusting the wave band of the incident pump beam so as to obtain a laser beam;

the second optical path adjusting component is arranged in front of the nonlinear crystal along the propagation direction of the second optical path and is used for adjusting the laser beam to propagate along a third optical path so as to be injected into the second laser structure;

the first optical path and the second optical path have the same propagation direction, and the second optical path and the third optical path have opposite propagation directions.

3. The wavelength tunable high power long wavelength infrared ultrafast laser system of claim 2, wherein the first optical path adjusting assembly comprises:

the two first reflectors are arranged oppositely and obliquely at intervals and used for converting the propagation route of the laser beam from the first light path to the second light path.

4. The wavelength tunable high power long wave infrared ultrafast laser system of claim 3, wherein said two first mirrors are parallel to each other.

5. The wavelength tunable high power long wavelength infrared ultrafast laser system of claim 2, wherein the second optical path adjusting assembly comprises:

and the two second reflecting mirrors are arranged oppositely and obliquely at intervals and used for converting the propagation route of the laser beam into the third light path from the second light path.

6. The wavelength tunable high power long wave infrared ultrafast laser system of claim 2, wherein said first laser structure further comprises:

and the second lens is arranged between the nonlinear crystal and the second light path adjusting component and is used for receiving the laser beam emitted by the nonlinear crystal and collimating the laser beam.

7. The wavelength tunable high power long wave infrared ultrafast laser system of claim 6, wherein said first laser structure further comprises:

and the filter is arranged between the second lens and the second light path adjusting component and is used for filtering residual signal light in the laser beam.

8. The wavelength tunable high power long-wavelength infrared ultrafast laser system of claim 2, wherein propagation directions of said first optical path, said second optical path and said third optical path are all parallel to each other.

9. The wavelength tunable high power long wave infrared ultrafast laser system of any one of claims 2 to 8, wherein the second laser structure comprises:

the polarization controller is arranged at the incident end of the third optical path and is used for controlling the external polarization state of the incident laser beam;

the third lens is arranged in front of the polarization controller along the propagation direction of the third optical path and is used for focusing the incident laser beam;

the Raman crystal is arranged in front of the third lens along the propagation direction of the third optical path and is used for adjusting the wave band of the incident laser beam;

and the fourth lens is arranged at the emergent end of the third optical path adjacent to the Raman crystal and is used for receiving the laser beam emitted from the Raman crystal and collimating the laser beam.

10. The wavelength tunable high power long wave infrared ultrafast laser system of claim 9, wherein the polarization controller includes a beam splitting prism and a half-wave plate disposed in front of the beam splitting prism in a propagation direction of the third optical path.