CN110880672B - High repetition frequency large energy nanosecond pulse laser and use method thereof - Google Patents
High repetition frequency large energy nanosecond pulse laser and use method thereof Download PDFInfo
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- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
- H01S3/1123—Q-switching
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- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
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- H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
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Abstract
本发明公开了一种高重频大能量纳秒级脉冲激光器及其使用方法,包括：泵浦激光器、激光增益池、非稳定谐振腔和电光调Q装置。泵浦激光器输出的泵浦激光光束从激光增益池的增益介质端面泵浦，透射至激光增益介质内，向所述谐振腔提供能量；激光在由凹面反射镜、凸面反射镜和刮刀镜组成的非稳定谐振腔中振荡，并通过电光调Q装置进行脉冲调制，最后脉冲激光从刮刀镜输出。本发明提供了一种单腔振荡实现高重频(≥200Hz)、大能量(≥20J)、窄脉宽的激光器。该激光器将具有效率高、结构简单、可放大性好、使用可靠、环境适应能力较强等特点。可以被广泛地使用在工业加工，特别是熔覆冲击强化领域。
The invention discloses a nanosecond pulse laser with high repetition frequency and high energy and a method for using the same. The pump laser beam output by the pump laser is pumped from the end face of the gain medium of the laser gain cell, transmitted into the laser gain medium, and provides energy to the resonator; It oscillates in an unstable resonant cavity, and is pulse-modulated by an electro-optical Q-switching device, and finally the pulsed laser is output from the scraper mirror. The invention provides a single-cavity oscillation laser capable of realizing high repetition frequency (≥200Hz), large energy (≥20J) and narrow pulse width. The laser will have the characteristics of high efficiency, simple structure, good magnification, reliable use and strong environmental adaptability. It can be widely used in industrial processing, especially in the field of cladding impact strengthening.
Description
Technical Field
The invention belongs to the technical field of high-energy pulse lasers, and particularly relates to a high-repetition-frequency high-energy nanosecond pulse laser and a method for realizing high-repetition-frequency high-energy nanosecond pulse by using a single resonant cavity.
Background
The large pulse energy nanosecond pulse laser has very important application requirements in the aspects of industry, scientific research and national defense. In industrial application, various lasers, especially high-energy lasers, are widely used, including laser processing, laser quenching, laser cladding, laser shock peening, laser cleaning, and the like. The high-energy laser has higher output power, so the method can also be used for direct laser rapid forming of parts, metal surface modification and other applications, and the most typical industrial application is that the service life of a metal material subjected to high-energy nanosecond pulse laser shock peening can be prolonged by several times or even longer. The large pulse energy laser also has wide national defense applications. Although lasers have been widely used in industrial applications and defense fields, the lasers used in laser processing (particularly cladding impact strengthening) and defense fields are far from meeting the application requirements due to the limitations of the current laser level. Therefore, it is highly desirable to develop a laser with high repetition rate, large pulse energy and narrow pulse width. In addition, in order to adapt to the application and popularization of the laser, higher requirements are also put forward on the cost and the cost of the laser, the complexity of a laser system, the volume and the weight, the reliability and the environmental adaptability.
Laser systems with single pulse energy greater than 100J have been reported, but the repetition rate is very low, generally lower than 10Hz, which limits some applications; the highest single pulse energy of the pulse laser with the hundred Hz magnitude is 5J, and the repetition frequency is 200 Hz; the two lasers both adopt MOPA structures, so that the system structure is very complex, the cost is very high, the efficiency is relatively low, the requirement on the operating environment is strict (the field operation requirement cannot be met), and the further amplification is difficult and serious; the pulse laser can be obtained by using a single resonant cavity oscillation mode with a simple structure, but is limited by the aperture of a solid laser spot and the size of an active modulation element, and the obtained single pulse energy is only hundreds of mJ magnitude at most, which is not enough to damage an optical system and is difficult to meet the requirements of special industrial processing.
Disclosure of Invention
In view of the defects in the prior art, the invention aims to provide a laser which realizes high repetition frequency (more than or equal to 200Hz), large energy (more than or equal to 20J) and narrow pulse width by single-cavity oscillation. The laser has the characteristics of high efficiency, simple structure, good amplifiability, reliable use, strong environment adaptability and the like. Can be widely used in the field of industrial processing (particularly cladding impact reinforcement).
In order to achieve the purpose, the technical scheme of the invention is as follows: in one aspect, a high repetition frequency large energy nanosecond pulse laser is provided, which includes: a pump laser to output a 808nm or 940nm pump source laser beam; a laser gain cell is a gain module capable of outputting laser spots with the aperture larger than 30mm multiplied by 30mm, and is implemented by adopting one of the laser technologies of realizing outputting large-aperture spots by adopting an immersion liquid cooling solid laser technology, a laser gain medium is immersed in cooling liquid with high transmittance, and high-efficiency heat exchange is carried out by utilizing high-speed convection of the liquid and the solid, the laser gain cell is implemented in the following modes (the structural reference adopted by the gain cell (OPTICS EXPRESS, Vol.24, No.13,15012 and 15020, 2016; OPTICS EXPRESS, Vol.26, No.11,13915 and 13926, 2016), an unstable resonant cavity is provided for a round-trip optical path so that the laser generates oscillation in the resonant cavity and outputs the laser, the laser gain cell consists of a concave reflecting mirror, a convex reflecting mirror and a scraper mirror, an electro-optical Q-regulating device is used for carrying out pulse modulation on the laser and consists of a thin film polaroid, a Pockel box and a lambda/4 wave plate, and is integrally arranged between the scraper mirror and the convex reflecting mirror, and the gain cell is used for regulating Defining the direction of the x axis, defining the light passing direction of the pump light as the direction of the y axis, and judging the direction of the z axis according to a right hand rule; the gain media in the laser gain pool are arranged along the x axis, and the two pump lasers are parallelly and oppositely arranged at two sides of the laser gain pool and are vertical to the arrangement direction of the gain media in the laser gain pool (along the y axis direction); a concave reflector, a laser gain cell, a scraper mirror, a film polaroid, a Pockels cell, a lambda/4 wave plate and a convex reflector are sequentially arranged along the x-axis direction; or the concave reflector, the laser gain pool, the scraper mirror and the film polaroid are sequentially arranged along the x-axis direction, the Pockels cell, the lambda/4 wave plate and the convex reflector are sequentially arranged behind the film polaroid along the y-axis direction, the concave surface of the concave reflector faces the laser gain pool, and the convex surface of the convex reflector faces the lambda/4 wave plate; the laser gain control method comprises the steps that a pump laser beam output by a pump laser is pumped from the end face (xz face) of a gain medium of a laser gain pool and is transmitted into the laser gain medium to provide gain for laser formation, the laser oscillates in an unstable resonant cavity formed by a concave reflecting mirror, a convex reflecting mirror and a scraper mirror, pulse modulation is carried out through an electro-optical Q-switching device, and finally pulse laser is output from the scraper mirror.
Based on the technical scheme, preferably, the pumping laser is a diode laser area array, a double-faced pump alignment continuous operation mode is adopted, the pumping repetition frequency is not less than 200Hz, the average power of single-faced array pumping is 10kW, the center wavelength is 808nm or 940nm, and the full width at half maximum of the spectrum is 3 nm.
Based on the above technical scheme, preferably, the laser gain cell adopts an immersion type liquid-cooled solid laser technology, the laser gain medium is immersed in a high-transmittance cooling liquid, pumping light is pumped from the end face (xz face) of the laser gain medium, and laser passes through the large face (yz face) of the laser gain medium. Structural references adopted by the gain cell (OPTICS EXPRESS, Vol.24, No.13,15012-
Based on the above technical solution, it is further preferable that the laser gain medium is a plurality of parallel-arranged crystals, glasses or ceramic sheets, and more preferably, the laser gain medium is Nd ion-doped crystals, Nd ion-doped glasses, Nd ion-doped ceramics, Yb ion-doped crystals, Yb ion-doped glasses, or Yb ion-doped ceramics.
Based on the above technical solution, preferably, the unstable resonator is a forward-branch unstable resonator structure composed of a concave mirror, a convex mirror, and a scraper mirror, and provides a back-and-forth optical path, so that the laser oscillates in the resonator and outputs the laser. . The curved surfaces of the concave reflector and the convex reflector are both plated with high-reflection dielectric films for oscillating laser, and the reflectivity for laser wavelength is more than 99.8%; the scraper mirror is plated with a high-reflection dielectric film for oscillating laser, and the scraper mirror and the optical axis of the laser are arranged at 45 degrees or 30 degrees, so that the incident angle of the laser is 45 degrees or 30 degrees, and the reflectivity of the laser to the laser wavelength is more than 99.8 percent.
Based on the technical proposal, the method has the advantages that,preferably, the electro-optical Q-switching device consists of a thin film polarizer, a Pockels cell and a lambda/4 wave plate, and is integrally arranged between the scraper mirror and the convex reflector. The thin film polarizer and the laser optical axis are arranged at an angle of 45 degrees or 55.6 degrees, so that laser is incident at an angle of 45 degrees or 55.6 degrees, and the structure of the electro-optic Q-switching device can be a polarizer transmission type electro-optic Q-switching structure or a polarizer reflection type electro-optic Q-switching structure by changing the oscillation starting mode in the resonant cavity; the laser surface of the film polaroid is plated with a high-reflection dielectric film in a vertical polarization state to the oscillation laser, and the reflectivity to the laser wavelength is more than 99.8%; the two sides of the film polaroid are plated with high-transmittance dielectric films for the horizontal polarization state of the oscillation laser, and the transmittance of the film polaroid for the laser wavelength is more than 99.5 percent; if the Q-switch is a polaroid transmission type electro-optical Q-switch, the electro-optical Q-switch process is as follows: the laser gain medium emits natural light under an LD pump, the natural light is changed into horizontal polarized light after being transmitted by a polaroid, if no voltage is applied to a Pockels cell crystal, the laser passes through the Pockels cell and a lambda/4 wave plate twice, the polarization state of the laser changes pi phase difference and is changed into vertical polarized light, oscillation cannot be formed in a resonant cavity, and when the number of particles of reversed energy level on the laser is accumulated to the maximum value, the lambda/4 voltage on the modulation crystal is suddenly applied, so that the laser is instantly in a high Q value state, avalanche type laser oscillation is generated, and a giant pulse in a horizontal polarization state is output from a scraper mirror; if the electro-optical Q-switch is a polarizer reflection type electro-optical Q-switch, the electro-optical Q-switch process is as follows: the laser gain medium emits natural light under an LD pump, the natural light is changed into vertical polarized light after being reflected by a polaroid, if no voltage is applied to a Pockels cell crystal, the laser passes through the Pockels cell and a lambda/4 wave plate twice, the polarization state of the laser changes pi phase difference and is changed into horizontal polarized light, oscillation cannot be formed in a resonant cavity, and when the number of particles of reversed energy level on the laser is accumulated to the maximum value, the lambda/4 voltage on the modulation crystal is suddenly applied, so that the laser is instantly in a high Q value state, avalanche type laser oscillation is generated, and a giant pulse in the vertical polarization state is output from a scraper mirror. The electro-optical pockels cell is potassium dideuterium phosphate (KD) with the caliber of more than 30mm multiplied by 30mm*P) crystal, its optical loss is low, the extinction ratio is high, the electrooptical performance is good, utilize its vertical electrooptical effect to realize the electro-optical Q-switch.
Based on the scheme, preferably, the output wavelength of the high repetition frequency large-energy nanosecond laser is 1064nm or 1030 nm.
Based on the above scheme, preferably, KD is adopted*The light-passing caliber of the P electro-optic Pockels cell is 30mm multiplied by 30mm, the amplification rate of the P electro-optic Pockels cell is 2, the output light spot is an annular hollow light spot with an outer side (60mm multiplied by 60mm) and an inner side (30mm multiplied by 30mm), the single-pulse energy is more than or equal to 20J, and the repetition frequency is more than or equal to 200 Hz.
The invention also provides a use method of the high repetition frequency large-energy nanosecond pulse laser, which comprises the following steps: pumping a pump laser beam output by the pump laser from the end face of a gain medium of the laser gain pool, transmitting the pump laser beam into the laser gain medium, and providing energy for the resonant cavity, wherein the laser gain medium is placed in a high-transmittance cooling liquid to provide gain for the formation of laser; the laser oscillates in an unstable resonant cavity consisting of a concave reflector, a convex reflector and a scraper mirror, and is subjected to pulse modulation through an electro-optical Q-switching device, wherein the electro-optical Q-switching device consists of a thin film polaroid, a Pockels cell and a lambda/4 wave plate and is arranged behind the scraper mirror, and finally, pulse laser is output from the scraper mirror.
Advantageous effects
Compared with the prior art, the invention has the beneficial effects that: in order to fill the blank of research on directly obtaining a high-repetition-frequency large-energy pulse laser in a single resonant cavity oscillation mode, the invention adopts an immersion type liquid-cooled solid laser combined with a specially designed unstable cavity structure and a large-caliber active Q-switching element, directly obtains large single-pulse energy in the single resonant cavity oscillation mode, has repetition frequency of more than or equal to 200Hz and good scaling amplification, and can meet important application in the aspects of industry, scientific research and national defense.
Drawings
FIG. 1 is a schematic structural diagram (polaroid transmission type electro-optic Q-switch) corresponding to a high repetition frequency large energy nanosecond pulse laser;
FIG. 2 is a schematic diagram of a structure corresponding to a high repetition frequency large energy nanosecond pulse laser (polarizer reflective electro-optic Q-switch);
in the figure: 1. the laser comprises a pump laser 2, a laser gain pool 3, a concave reflector 4, a scraper mirror 5, a thin film polaroid 6, a Pockels cell 7, a lambda/4 wave plate 8 and a convex reflector.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As described above, in view of the problem in the prior art that a single resonator oscillation mode directly generates a high repetition frequency large energy pulse laser is difficult to obtain.
Example 1
The first embodiment of the present invention is shown in fig. 1, and the present invention provides a high repetition frequency large energy nanosecond pulse laser (polarizer transmissive electro-optic Q-switch) comprising:
a pump laser 1; the device comprises a laser gain cell 2, a concave reflector 3, a convex reflector 8, a scraper mirror 4, a thin film polarizer 5, a Pockels cell 6 and a lambda/4 wave plate 7, wherein the magnification M of the concave reflector 3 and the convex reflector 8 is 2, the cavity length (the cavity length is the optical distance between the concave reflector and the convex reflector) is 1500mm, and the curvature radiuses of the concave reflector and the convex reflector are 6000mm and 3000mm respectively; defining the light passing direction of the oscillation laser in the laser gain pool 2 as the x-axis direction, defining the light passing direction of the pump light as the y-axis direction, and judging the z-axis direction according to a right-hand rule; the gain media in the laser gain pool are arranged along the x axis, and the two pump lasers 1 are parallelly and oppositely arranged at two sides of the laser gain pool 2 and are vertical to the arrangement direction of the gain media in the laser gain pool 2 (along the y axis direction); the X-axis direction is sequentially provided with a concave reflector 3, a laser gain cell 2, a scraper mirror 4, a film polaroid 5, a Pockels cell 6, a lambda/4 wave plate 7 and a convex reflector 8; the concave surface of the concave reflector 3The laser gain cell is faced, the convex surface of the convex reflector 8 faces the lambda/4 wave plate, the scraper mirror and the laser optical axis are arranged at an angle of 45 degrees, and the thin film polarizer and the laser optical axis are arranged at an angle of 45 degrees; the scraper mirror is plated with a high-reflection dielectric film for oscillating laser, and the reflectivity is more than 99.8%; the laser surface of the film polaroid is plated with a high-reflection dielectric film in a vertical polarization state of oscillation laser, the reflectivity of the high-reflection dielectric film to the laser wavelength is more than 99.8%, and the two sides of the film polaroid are plated with high-transmission dielectric films in a horizontal polarization state of the oscillation laser, and the transmissivity of the high-transmission dielectric films to the laser wavelength is more than 99.5%; the pump laser beam output by the pump laser 1 has a wavelength of 808nm, the repetition frequency is not less than 200Hz, the average power of single-sided array pumping is 10kW, the pump is pumped from the end face (xz face) of a gain medium of the laser gain pool 2 and is transmitted into the laser gain medium to provide gain for the formation of laser, the laser oscillates in an unstable resonant cavity consisting of a concave reflector 3, a convex reflector 8 and a scraper mirror 4, pulse modulation is carried out through an electro-optical Q-switching device, and finally pulse laser is output from the scraper mirror. KD with light-passing aperture of 30mm multiplied by 30mm is adopted*P electro-optic pockels cells. YAG crystal as gain medium, and laser aperture greater than 60mm × 60 mm; under the pumping of a pump laser 1, natural light is emitted and is changed into horizontal polarized light after being transmitted through a film polaroid 5, if no voltage is applied to a Pockels cell 6 crystal, laser passes through the Pockels cell 6 and a lambda/4 wave plate 7 twice, the polarization state of the laser changes pi phase difference and is changed into vertical polarized light, oscillation cannot be formed in a resonant cavity, when the number of particles on the upper energy level of the laser is accumulated to the maximum value, lambda/4 voltage on the modulation crystal is suddenly applied, the laser is instantly in a high Q value state to generate avalanche type laser oscillation, finally, a horizontal polarization state giant pulse is output from a scraper mirror 4, the output laser wavelength is 1064nm, the output light spot is an annular hollow light spot inside (30mm x 30mm) outside (60mm x 60mm), the energy of the single pulse is not less than 20J, and the repetition frequency is not less than 200 Hz.
Example 2
Second embodiment of the invention as shown in fig. 2, the present invention provides a high repetition frequency large energy nanosecond pulse laser (polarizer reflective electro-optic Q-switch) which is different from the embodiment 1 only in the electro-optic Q-switch portion, and the other is the same as the embodiment 1. The electro-optical Q-switching device adopts a polaroid reflection type electro-optical Q-switching; the film polarizer is characterized in that a concave reflector 3, a laser gain pool 2, a scraper mirror 4 and a film polarizer 5 are sequentially arranged along the x-axis direction, a Pockels cell 6, a lambda/4 wave plate 7 and a convex reflector 8 are sequentially arranged behind the film polarizer 5 along the y-axis direction, the concave surface of the concave reflector 3 faces the laser gain pool, and the convex surface of the convex reflector 8 faces the lambda/4 wave plate; the electro-optical Q-switching process is as follows: YAG crystal emits natural light under the pump of the pump laser 1, and becomes vertical polarized light after being reflected by a polaroid, if no voltage is applied on the Pockels cell crystal, the laser changes pi phase difference after passing through the Pockels cell and the lambda/4 wave plate twice, and becomes horizontal polarized light, and can not form oscillation in the resonant cavity, when the number of energy level reversal particles on the laser is accumulated to the maximum value, the lambda/4 voltage on the modulation crystal is suddenly applied, so that the laser is instantly in a high Q value state, avalanche type laser oscillation is generated, a giant pulse in a vertical polarization state is output from the scraper mirror, the laser wavelength is 1064nm, the output light spot is an annular hollow light spot in an inner side (30mm x 30mm) of an outer side (60mm x 60mm), the energy of the single pulse is not less than 20J, and the repetition frequency is not less than 200 Hz.
Example 3
The third embodiment of the present invention is shown in fig. 1, and the present invention provides a high repetition frequency large energy nanosecond pulse laser (polarizer transmissive electro-optic Q-switch), which is different from example 1 only in the gain medium portion in the pump laser 1 and the laser gain cell 2, and the other portions are the same.
The wavelength of a pump laser beam output by the pump laser 1 is 940nm, the repetition frequency is more than or equal to 200Hz, the average power of single-sided array pumping is 10kW, the pump laser beam is pumped from the end face (xz face) of a gain medium of the laser gain pool 2 and is transmitted into Yb laser gain medium, YAG ceramic, gain is provided for laser forming, the output laser wavelength is 1030nm, an output light spot is an annular hollow light spot which is outside (60mm multiplied by 60mm) and inside (30mm multiplied by 30mm), the single pulse energy is more than or equal to 20J, and the repetition frequency is more than or equal to 200 Hz.
Example 4
A fourth embodiment of the present invention is shown in fig. 1, and the present invention provides a high repetition frequency high energy nanosecond pulse laser (polarizer transmissive electro-optic Q switch) having only a concave mirror 3 and a convex mirror 8, which are different from those of example 1, and the other parts are the same. The magnification ratio M of the unstable resonant cavity is 3, the cavity length is 1500mm, and the curvature radius of the concave reflector and the curvature radius of the convex reflector are 4500mm and 1500mm respectively; the laser aperture of the laser gain medium in the laser gain pool 2 is larger than 90mm multiplied by 90 mm; the output laser wavelength is 1064nm, the output light spot is an annular hollow light spot with the outer side (90mm multiplied by 90mm) and the inner side (30mm multiplied by 30mm), the single pulse energy is more than or equal to 20J, and the repetition frequency is more than or equal to 200 Hz.
In summary, in order to fill the gap in research on directly obtaining a high repetition frequency and large energy pulse laser in a single resonant cavity oscillation mode, the invention adopts an immersion type liquid cooling solid laser combined with a specially designed unstable cavity structure and a large-caliber active Q-switching element, directly obtains large single pulse energy in the single resonant cavity oscillation mode, has repetition frequency of more than or equal to 200Hz and good scaling amplification, and can meet important application in the aspects of industrial, scientific research and national defense.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (11)
1. A high repetition frequency large energy nanosecond pulsed laser, comprising: the device comprises two pump lasers, a laser gain pool, an electro-optical Q-switching device and an unstable resonant cavity; the unstable resonant cavity consists of a concave reflector, a convex reflector and a scraper mirror; the electro-optical Q-switching device consists of a thin film polaroid, a Pockels cell and a lambda/4 wave plate;
defining the light transmission direction of oscillation laser in a laser gain pool as an x-axis direction, defining the light transmission direction of pump light as a y-axis direction, and judging the direction of a z-axis according to a right-hand rule;
the gain media in the laser gain pool are arranged along the x axis, and the two pump lasers are parallelly and oppositely arranged at two sides of the laser gain pool and are vertical to the arrangement direction of the gain media in the laser gain pool, namely along the y axis; the X-axis direction is sequentially provided with a concave reflector, a laser gain pool, a scraper mirror, a film polaroid, a Pockels cell, a lambda/4 wave plate and a convex reflector, or the X-axis direction is sequentially provided with a concave reflector, a laser gain pool, a scraper mirror and a film polaroid, and the Y-axis direction is sequentially provided with a Pockels cell, a lambda/4 wave plate and a convex reflector behind the film polaroid; the concave surface of the concave reflector faces the laser gain cell, and the convex surface of the convex reflector faces the lambda/4 wave plate;
the laser device comprises a laser gain pool, an electro-optical Q-switching device, a laser gain pool, an xz plane pump, a laser gain cavity, a scraper mirror, an electro-optical Q-switching device and a control module, wherein the gain medium end face of the laser gain pool is used for pumping a pump laser beam output by the pump laser device, namely the xz plane, and transmitting the pump laser beam into a laser gain medium to provide gain for laser formation, the laser oscillates in an unstable resonant cavity formed by the concave reflector, the convex reflector and the scraper mirror, pulse modulation is carried out.
2. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the pumping laser is a diode laser area array, a double-sided pump alignment continuous operation mode is adopted, the pumping repetition frequency is not less than 200Hz, the average power of single-sided array pumping is 10kW, the output center wavelength is 808nm or 940nm, and the full width at half maximum of the spectrum is 3 nm.
3. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the laser gain pool is a gain module capable of outputting laser spots with the calibers larger than 30mm multiplied by 30mm, the laser gain pool adopts the immersion liquid-cooled solid laser technology to immerse a laser gain medium in high-transmittance cooling liquid, pumping light is pumped from the xz end face of the laser gain medium, and laser passes through the yz face of the laser gain medium.
4. The high repetition frequency large energy nanosecond pulsed laser according to claim 3, wherein: the laser gain medium is a crystal, glass or ceramic chip which are arranged in parallel.
5. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the unstable resonant cavity is a positive branch unstable concave-convex cavity structure consisting of a concave reflector, a convex reflector and a scraper mirror, and a back-and-forth light path is provided so that laser oscillates in the resonant cavity and is output; the curved surfaces of the concave reflector and the convex reflector are both plated with high-reflection dielectric films for oscillating laser, and the reflectivity for laser wavelength is more than 99.8%; the scraper mirror is plated with a high-reflection dielectric film for oscillating laser; the scraper mirror and the laser optical axis are arranged at an angle of 45 degrees or 30 degrees, and the reflectivity of the laser wavelength is greater than 99.8 percent.
6. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the electro-optic Q-switching device structure can be a polaroid transmission type electro-optic Q-switching structure or a polaroid reflection type electro-optic Q-switching structure; the film polaroid and the laser optical axis are arranged at an angle of 45 degrees or 55.6 degrees; the laser surface of the film polaroid is plated with a high-reflection dielectric film in a vertical polarization state of oscillation laser, the reflectivity of the film polaroid to laser wavelength is more than 99.8%, the two sides of the film polaroid are plated with high-transmission dielectric films in a horizontal polarization state of the oscillation laser, and the transmissivity of the film polaroid to the laser wavelength is more than 99.5%.
7. The high repetition frequency large energy nanosecond pulsed laser according to claim 6, wherein: the pockels cell is potassium dideuterium phosphate (KD) with the caliber of more than 30mm multiplied by 30mm*P) crystals.
8. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the output wavelength of the high repetition frequency and large energy nanosecond laser is 1064nm or 1030 nm.
9. The high repetition frequency large energy nanosecond pulsed laser according to claim 1, wherein: the amplification rate of the unstable resonant cavity is 2, when the light-passing aperture of the Pockels cell crystal is 30mm multiplied by 30mm, the output light spot is an annular hollow light spot with the outer side of 60mm multiplied by 60mm and the inner side of 30mm multiplied by 30mm, the single pulse energy is more than or equal to 20J, and the repetition frequency is more than or equal to 200 Hz.
10. Use of the high repetition frequency large energy nanosecond pulsed laser according to any one of claims 1-9, characterized in that the use comprises:
pumping a pump laser beam output by a pump laser from the end face of a gain medium of a laser gain pool, transmitting the pump laser beam into the laser gain medium, and providing energy for the resonant cavity, wherein the laser gain medium is placed in a high-transmittance cooling liquid to provide gain for the formation of laser; the laser oscillates in an unstable resonant cavity consisting of a concave reflector, a convex reflector and a scraper mirror, pulse modulation is carried out through an electro-optical Q-switching device, and finally pulse laser is output from the scraper mirror, so that the laser with single-cavity oscillation, high repetition frequency of more than or equal to 200Hz, high energy of more than or equal to 20J and narrow pulse width is provided.
11. The high repetition frequency large energy nanosecond pulsed laser according to claim 4, wherein: the laser gain medium is a crystal doped with Nd ions, glass doped with Nd ions, ceramic doped with Nd ions, a crystal doped with Yb ions, glass doped with Yb ions, or ceramic doped with Yb ions.
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| CN113889828B (en) * | 2020-07-03 | 2024-01-09 | 中国科学院大连化学物理研究所 | High-power liquid cooling pulse solid laser |
| CN112636156B (en) * | 2020-12-24 | 2022-01-11 | 北京遥测技术研究所 | Satellite-borne high-energy dual-wavelength all-solid-state pulse laser |
| CN113161855B (en) * | 2021-04-23 | 2022-09-20 | 福州市纳飞光电科技有限公司 | Low-voltage high-modulation-speed high-energy electro-optic Q-switched laser |
| CN113555763A (en) * | 2021-08-19 | 2021-10-26 | 广东粤港澳大湾区硬科技创新研究院 | 266nm pulse solid laser with high energy, high repetition frequency and high beam quality |
| CN114865436B (en) * | 2022-04-29 | 2025-08-15 | 河北工业大学 | Narrow pulse width laser with high repetition frequency and high beam quality |
| CN115291192B (en) * | 2022-08-11 | 2025-05-02 | 中国科学院长春光学精密机械与物理研究所 | Integrated laser distance measuring device |
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