CN111668691A - A high-power high-repetition-rate 100-picosecond laser - Google Patents

Abstract

The invention discloses a high-power and high-repetition-frequency hundred-picosecond laser, comprising: a seed laser emits a first frequency seed light, enters a double-pass amplifier through a first optical isolator for amplification, and passes through a first reflecting mirror, a first After the beam shaper, the first single-pass amplifier, the second mirror, the third mirror, the second beam shaper and the second optical isolator, enter the SBS pulse compressor to compress the first frequency seed light to the second frequency laser ; The second frequency laser is amplified by the fourth mirror, the third beam shaper, several second single-pass amplifiers, the fifth mirror, the sixth mirror, the fourth beam shaper, and several four-pass slat amplifiers in turn; The amplified laser light passes through the seventh reflector, the fifth beam shaper, and the frequency multiplier to generate a third frequency laser light, which is finally output through a beam splitter. The invention overcomes the problems of small size of solid SBS medium, damage of high-power laser to SBS material, and low output laser power of narrow pulse width.

Description

A high-power high-repetition-rate 100-picosecond laser

technical field

The invention relates to the field of lasers, in particular to a high-power and high-repetition-frequency hundred picosecond laser.

Background technique

With the deepening of people's exploration of space, the activities of human beings entering space are also increasing, but similar activities also produce more and more space debris, which has a great impact on satellite launch and space exploration. Debris in space orbit needs to be detected. The traditional space target measurement is achieved by radar, but there is no corner reflector on the surface of space debris, which cannot receive and reflect the signal sent by the radar. It is not feasible to measure it with radar. Detection has become a major research hotspot in recent years.

The laser source used for space debris detection needs to transmit a very long distance, so it requires high energy, and in order to achieve high-precision space measurement, it also requires good beam quality, narrow pulse width and high repetition frequency. Therefore, obtaining a narrow linewidth, high power, and high repetition frequency laser source is a key step in optimizing space detection.

The traditional method of space debris detection is to use nanosecond lasers combined with master oscillator power amplification (MOPA), but the current pulse width cannot meet people's requirements for ranging accuracy, so people are exploring the realization of high-energy picosecond lasers. method.

At present, the technical means to obtain picosecond pulsed laser output is mainly to adopt the passive mode-locking method of saturable absorber (SESAM). However, due to the low damage threshold of the saturable absorber, the output power of the passively mode-locked picosecond pulsed laser is limited, and complex structures such as regenerative amplifiers are often required for amplification. The cost is high and the stability is difficult to control. Therefore, using high-energy nanosecond pulse compression to obtain high-energy output in the order of hundreds of picoseconds and amplify it can effectively avoid the difficult and efficient amplification problem encountered by SESAM mode-locked lasers. It is expected to improve the ranging accuracy by 1-2 orders of magnitude, and the cost of the laser is effectively controlled and the stability is higher.

SUMMARY OF THE INVENTION

The invention provides a high-power and high-repetition-frequency 100-picosecond laser. The invention combines multiple structures such as multi-stage amplification, multiple stimulated Brillouin scattering (SBS) solid media in series, and compression after amplification. This method overcomes the problems of small size of solid SBS medium, damage to SBS material caused by high-power laser, and low output laser power with narrow pulse width.

A high-power high-repetition-frequency hundred-picosecond laser, the laser comprising:

The seed laser emits seed light of the first frequency, and after passing through the first optical isolator, it enters a double-pass amplifier for amplification, and then passes through the first mirror, the first beam shaper, the first single-pass amplifier, the second mirror, and the first mirror in turn. After the three mirrors, the second beam shaper and the second optical isolator, enter the SBS pulse compressor to compress the first frequency seed light to the second frequency laser;

The second frequency laser is sequentially amplified by a fourth mirror, a third beam shaper, several second single-pass amplifiers, a fifth mirror, a sixth mirror, a fourth beam shaper, and several four-pass slat amplifiers;

The amplified laser passes through the seventh reflector, the fifth beam shaper, and the frequency multiplier to generate a third frequency laser, and finally outputs through a beam splitter.

Wherein, the first optical isolator and the second optical isolator are both composed of a first polarizer, a Faraday rotator, and a first half-wave plate, so that the incident seed light passes in one direction, and the light transmitted in the opposite direction The exit is deflected when passing through the first polarizer due to the change in polarization state.

Further, the double-pass amplifier is composed of a second polarizer, a first side pump module, a first quarter-wave plate and a zero-degree total reflection mirror;

The first quarter-wave plate is used to change the polarization state of the seed light; the zero-degree total reflection mirror is coated with a total reflection film for the first frequency seed light, and forms an included angle of 90° with the incident direction of the first frequency seed light to achieve Total reflection.

Wherein, the first single-pass amplifier is composed of a second side pump module, a first 90° quartz rotor, and a third side pump module.

Further, the SBS pulse compressor is composed of a third polarizer, a second quarter-wave plate, a first focusing lens, and several Brillouin media;

The second quarter-wave plate is used to change the laser polarization state after pulse compression; the first focusing lens focuses the incident seed light into the Brillouin medium; the first frequency seed light is in the horizontal polarization state and transmits into the third The polarizer is converted into elliptically polarized light through the second quarter-wave plate, and is focused into the Brillouin medium by the first focusing lens to generate the second frequency laser. After the second frequency laser is backscattered and pulse compressed, it passes through The first focusing lens and the second quarter-wave plate become vertically polarized, and finally the compressed laser light of the second frequency is reflected out of the SBS pulse compressor through the third polarizer.

In specific implementation, the second single-pass amplifier consists of a fourth side pump module, a second 90° quartz rotor, a second focusing lens, a first vacuum tube, a third focusing lens, a fifth side pump module, a second half A wave plate and a fourth polarizer are formed, wherein a first aperture diaphragm is arranged in the first vacuum tube;

The second focusing lens, the first vacuum tube, the first aperture diaphragm and the third focusing lens together form a spatial filter, which is used to eliminate the spontaneous radiation amplification effect generated during the amplification process; the second half-wave plate and the fourth Polarizer combinations are used to control the laser output energy without changing the laser polarization state.

The four-way slab amplifier consists of a fifth polarizer, a slab gain medium, an eighth reflector, a sixth beam shaper, a ninth reflector, a tenth reflector, a seventh beam shaper, a third One-half wave plate, eleventh reflection mirror, fourth focusing lens, second vacuum tube, fifth focusing lens and third one-half wave plate, wherein the second vacuum tube is provided with a second aperture diaphragm;

The sixth beam shaper and the seventh beam shaper are composed of a single optical lens or optical lens group, and are used to shape the amplified seed beam to reduce the negative effect of reducing the amplification efficiency caused by the beam divergence; the third quarter-wave The mirror is used to change the polarization state of the laser during the amplification process; the eleventh mirror is coated with a total reflection film for the second frequency laser, and forms an angle of 90° with the incident direction of the second laser, so as to realize the full reflection of the second frequency laser reflection.

The beneficial effects of the technical scheme provided by the present invention are:

1. The laser uses multiple solid SBS media in series to increase the working distance of SBS pulse compression, which can effectively compress high repetition frequency laser pulses, improve pulse compression efficiency, and make up for the small size of a single solid SBS medium. ;

2. The laser uses SBS to compress the pulse first, and then amplifies the laser power, which avoids the problem of high-power laser damage to the SBS material;

3. The laser uses a multi-stage amplification method of double-pass amplifier and single-pass amplifier to amplify the seed laser, and at the same time uses a four-pass slat amplifier to amplify the pulse-compressed seed light, which can achieve hundreds of picosecond pulses. Effective amplification of laser, and can improve energy utilization and amplification efficiency.

Description of drawings

1 is a schematic structural diagram of a high-power, high-repetition-rate, 100-picosecond laser;

2 is a schematic structural diagram of a first optical isolator;

FIG. 3 is a schematic structural diagram of a dual-pass amplifier;

4 is a schematic structural diagram of a first single-pass amplifier;

Fig. 5 is the structural representation of SBS pulse compressor;

6 is a schematic structural diagram of a second single-pass amplifier;

7 is a schematic structural diagram of a four-way slat amplifier;

FIG. 8 is a schematic structural diagram of a series connection of multi-stage four-way slat amplifiers.

In the accompanying drawings, the list of components represented by each number is as follows:

1: seed laser; 2: first optical isolator;

3: Double-pass amplifier; 4: First reflector;

5: the first beam shaper; 6: the first single-pass amplifier;

7: The second reflector; 8: The third reflector;

9: Second beam shaper; 10: Second optical isolator;

11: SBS pulse compressor; 12: Fourth mirror;

13: The third beam shaper; 14: The second single-pass amplifier;

15: Fifth reflector; 16: Sixth reflector;

17: Fourth beam shaper; 18: Four-way slat amplifier;

19: seventh mirror; 20: fifth beam shaper;

21: Frequency multiplier; 22: Beam splitter.

in

2-1: First polarizer; 2-2: Faraday rotator;

2-3: The first half wave plate;

3-1: Second polarizer; 3-2: First side pump module;

3-3: The first quarter wave plate; 3-4: Zero degree total reflection mirror;

6-1: The second side pump module; 6-2: The first 90° quartz rotor;

6-3: The third side pump module;

11-1: The third polarizer; 11-2: The second quarter wave plate;

11-3: first focusing lens; 11-4: Brillouin medium;

14-1: The fourth side pump module; 14-2: The second 90° quartz rotor;

14-3: The second focusing lens; 14-4: The first vacuum tube;

14-5: The first aperture diaphragm; 14-6: The third focusing lens;

14-7: The fifth side pump module; 14-8: The second half wave plate;

14-9: Fourth polarizer;

18-1: Fifth polarizer; 18-2: Slatted gain medium;

18-3: Eighth mirror; 18-4: Sixth beam shaper;

18-5: Ninth reflector; 18-6: Tenth reflector;

18-7: seventh beam shaper; 18-8: third quarter wave plate;

18-9: Eleventh mirror; 18-10: Fourth focusing lens;

18-11: The second vacuum tube; 18-12: The second aperture diaphragm;

18-13: Fifth focusing lens; 18-14: Third half-wave plate.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention are further described in detail below.

By understanding the shortcomings of traditional space target detection technology, it is found that the use of lasers can realize fast and accurate detection of space targets, especially the measurement of space debris in low-Earth orbit, which is important for satellite launch and further space exploration. significance. In order to achieve long-distance space target detection by laser, the laser source used is required to have high energy, and to achieve high-precision space measurement, it is also required to have good beam quality, narrow pulse width and high repetition frequency. Therefore, obtaining a narrow linewidth, high power, and high repetition frequency laser source is a key step in optimizing space detection. The SESAM passive mode-locking method can obtain a narrow linewidth laser output in the picosecond order, but due to the low damage threshold of the saturable absorber, the output power of the pulsed laser is greatly limited.

To sum up, the present invention proposes to obtain a high power, narrow linewidth, high repetition frequency laser source for space debris detection by combining multi-stage oscillation power amplification and SBS pulse compression with injected seed light.

In order to solve the problem that the traditional space target measurement technology is not suitable for space debris detection, an example of the present invention proposes a high-power, high-repetition-frequency, 100-picosecond laser. Referring to FIG. 1, a high-power, high-repetition-frequency, 100-picosecond laser includes: Seed laser 1, first optical isolator 2, double-pass amplifier 3, first mirror 4, first beam shaper 5, first single-pass amplifier 6, second mirror 7, third mirror 8, second beam shaper 9, second optical isolator 10, SBS pulse compressor 11, fourth mirror 12, third beam shaper 13, second single-pass amplifier 14, fifth mirror 15, sixth mirror 16, A fourth beam shaper 17 , a four-way slat amplifier 18 , a seventh mirror 19 , a fifth beam shaper 20 , a frequency multiplier 21 , and a beam splitter 22 .

Among them, the seed laser 1 emits nanosecond seed light of the order of kHz of single longitudinal mode of the first frequency (ω _p ), after passing through the first optical isolator 2 , it enters a double-pass amplifier 3 for amplification, and then passes through the first optical isolator 3 in turn. After the mirror 4, the first beam shaper 5, the first single-pass amplifier 6, the second mirror 7, the third mirror 8, the second beam shaper 9 and the second optical isolator 10, enter the SBS pulse compressor 11 Compress the nanosecond seed light of the first frequency to the laser light of the second frequency (ω _s ), the unit is hundreds of picoseconds;

The compressed laser passes through the fourth reflector 12, the third beam shaper 13, several second single-pass amplifiers 14, the fifth reflector 15, the sixth reflector 16, the fourth beam shaper 17, and several four-way plates in sequence. bar amplifier 18 for amplification;

The amplified laser light passes through the seventh reflecting mirror 19 , the fifth beam shaper 20 , and the frequency multiplier 21 to generate laser light with a third frequency (which is ω _H ), which is finally output through the beam splitter 22 .

Among them, the first beam shaper 5, the second beam shaper 9, the third beam shaper 13, the fourth beam shaper 17 and the fifth beam shaper 20 are used to adjust the divergence angle and aperture of the light beam, and are formed by a single optical beam shaper. Lens or optical lens group composition.

In specific implementation, the first reflecting mirror 4, the second reflecting mirror 7, the third reflecting mirror 8, the fourth reflecting mirror 12, the fifth reflecting mirror 15, the sixth reflecting mirror 16 and the seventh reflecting mirror 19 are all flat reflecting mirrors , which is highly inverse to the seed light of the first frequency. The beam splitter 22 is coated with an anti-reflection coating for the second frequency (ω _s ) laser light and a total reflection coating for the third frequency (ω _H ) laser light.

Referring to FIG. 2, both the first optical isolator 2 and the second optical isolator 10 are composed of a first polarizer 2-1, a Faraday rotator 2-2, and a first half-wave plate 2-3; The seed light passes through the first optical isolator 2 and the second optical isolator 10 in one direction, and the reversely transmitted light is deflected and exited when passing through the first polarizer 2-1 due to the change of the polarization state, so it cannot pass through the first optical isolator 2 and the second optical isolator 10 , thereby protecting the seed laser 1 .

Referring to FIG. 3, the double-pass amplifier 3 is composed of a second polarizer 3-1, a first side pump module 3-2, a first quarter wave plate 3-3 and a zero-degree total reflection mirror 3-4; the first four The one-wave plate 3-3 is used to change the polarization state of the seed light; the zero-degree total reflection mirror 3-4 is coated with a total reflection film for the seed light of the first frequency, and forms an angle of 90° with the incident direction of the laser to realize the Total reflection of the first frequency seed light; the first frequency seed light incident to the double-pass amplifier 3 is in a horizontal polarization state, transmitted into the second polarizer 3-1, amplified by the first side pump module 3-2, and passed through the second polarizer 3-1. A quarter-wave plate 3-3 becomes elliptically polarized light, and then total reflection occurs at the zero-degree total reflection mirror 3-4, and the seed light after total reflection passes through the first quarter-wave plate 3-3 to become The vertical polarization state is then amplified again by the first side pump module 3-2 for the second time, and the seed light that is amplified for the last two times and becomes the vertical polarization state is reflected out of the double-pass amplifier 3 through the second polarizer 3-1 to complete The whole process of double-pass amplification.

Referring to FIG. 4, the first single-pass amplifier 6 is composed of a second side pump module 6-1, a first 90° quartz rotor 6-2, and a third side pump module 6-3; the first 90° quartz rotor 6-2 is used for The polarization direction of the seed light is rotated by 90° (in specific implementation, other values may also be used, which are not limited in this embodiment of the present invention) to compensate for some negative thermal effects generated during the amplification process.

5, the SBS pulse compressor 11 is composed of a third polarizer 11-1, a second quarter-wave plate 11-2, a first focusing lens 11-3, and several Brillouin media 11-4; the second The quarter-wave plate 11-2 is used to change the laser polarization state after pulse compression; the first focusing lens 11-3 focuses the incident seed light into the Brillouin medium 11-4; it is incident on the SBS pulse compressor 11 The seed light of the first frequency is in the horizontal polarization state, transmitted into the third polarizer 11-1, becomes elliptically polarized light through the second quarter-wave plate 11-2, and is focused to the cloth through the first focusing lens 11-3. The second frequency laser is generated in the Lillouin medium 11-4. After backscattering and pulse compression, the second frequency laser passes through the first focusing lens 11-3 again, and then passes through the second quarter-wave plate 11-2 to become In the vertical polarization state, the last pulse-compressed laser light of the second frequency is reflected out of the SBS pulse compressor 11 through the third polarizer 11-1.

Referring to FIG. 6, the second single-pass amplifier 14 is composed of a fourth side pump module 14-1, a second 90° quartz rotor 14-2, a second focusing lens 14-3, a first vacuum tube 14-4 (the first vacuum tube 14- 4 is provided with a first aperture diaphragm 14-5), a third focusing lens 14-6, a fifth side pump module 14-7, a second half-wave plate 14-8 and a fourth polarizer 14- 9 composition; the second focusing lens 14-3, the first vacuum tube 14-4, the first aperture diaphragm 14-5 and the third focusing lens 14-6 together form a spatial filter, which is used to eliminate spontaneous Radiation Amplification (ASE) effect; the second half wave plate 14-8 and the fourth polarizer 14-9 in combination are used to control the laser output energy without changing the laser polarization state.

Referring to FIG. 7, the four-way slat amplifier 18 is composed of a fifth polarizer 18-1, a slat gain medium 18-2, an eighth mirror 18-3, a sixth beam shaper 18-4, and a ninth mirror 18- 5. The tenth mirror 18-6, the seventh beam shaper 18-7, the third quarter wave plate 18-8, the eleventh mirror 18-9, the fourth focusing lens 18-10, the second Vacuum tube 18-11, second aperture diaphragm 18-12, fifth focusing lens 18-13, third half-wave plate 18-14; sixth beam shaper 18-4, seventh beam shaper 18-7 is composed of a single optical lens or optical lens group, which is used to shape the amplified seed beam to reduce the negative effects such as reducing the magnification efficiency caused by beam divergence; the third quarter-wave plate 18-8 is used to change the The laser polarization state during the amplification process; the eleventh mirror 18-9 is coated with a total reflection film for the second frequency laser, and forms an angle of 90° with the laser incident direction to achieve total reflection of the second frequency laser; incident The second frequency laser to the four-way slat amplifier 18 is in a horizontal polarization state, transmitted into the fifth polarizer 18-1, and then passed through the slat gain medium 18-2 for the first time (first amplification), through the eighth After the mirror 18-3, the sixth beam shaper 18-4, the ninth mirror 18-5, the second pass through the slat gain medium 18-2 (second amplification), and then through the tenth mirror 18- 6 and the seventh beam shaper 18-7, through the third quarter-wave plate 18-8 into elliptically polarized light, and then total reflection at the eleventh mirror 18-9, the second frequency after total reflection The laser becomes vertically polarized again via the third quarter wave plate 18-8, then passes through the seventh beam shaper 18-7 and the tenth mirror 18-6 again, and passes through the slab gain medium 18- 2 (the third amplification), and then pass through the ninth mirror 18-5, the sixth beam shaper 18-4 and the eighth mirror 18-3 in sequence, and then pass through the slat gain medium 18-2 for the fourth time to amplify (The fourth magnification), the second frequency laser that has been magnified for four times and has become vertically polarized is reflected by the fifth polarizer 18-1; the fourth focusing lens 18-10, the second vacuum tube 18-11 (wherein the The two vacuum tubes 18-11 are provided with a second aperture aperture 18-12), a second aperture aperture 18-12, and a fifth focusing lens 18-13 to form a spatial filter, which is used to eliminate the The ASE effect improves the beam quality; the third half-wave plate 18-14 is used to control the polarization state of the laser, on the one hand, it is convenient for multi-stage coupling four-pass amplification, and on the other hand, it is beneficial to control the deflection and output of the amplified laser.

Referring to FIG. 8 , a plurality of four-pass slat amplifiers 18 can be connected in series to amplify the second frequency (ω _s ) laser light according to power requirements. In practical application, the gain medium of the double-pass amplifier 3, the first single-pass amplifier 6, the second single-pass amplifier 14 and the four-pass slab amplifier 18 are the same (eg: Nd:YAG), wherein the double-pass amplifier 3 and the first The end faces of the gain medium in the single-pass amplifier 6 are all coated with a dielectric film that antireflects the seed light of the first frequency (ω _p ), and the end faces of the gain medium in the second single-pass amplifier 14 and the four-pass strip amplifier 18 are both coated with anti-reflection dielectric films. The second frequency (ω _s ) laser antireflection dielectric film can also increase or decrease the number of the second single-pass amplifiers 14 according to the power requirements; the SBS pulse compressor 11 adopts the way of connecting a plurality of solid SBS materials in series, and the SBS medium can be Fused quartz, or CaF ₂ , or sapphire crystal; both ends of the slat gain medium 18-2 have a certain end face cutting angle α (~45°) to improve energy utilization; the frequency multiplier 21 can be potassium titanyl phosphate (KTP ) or lithium triborate (LBO) crystal, both ends of which are coated with antireflection coatings for the second frequency (ω _s ) laser and the third frequency (ω _H ) laser generated after frequency doubling.

The Brillouin frequency shift of the Brillouin medium 11-4 is ω _Ω , and the second frequency ω _s =ω _p -ω _Ω , wherein the Brillouin frequency shift ω _Ω is far smaller than the first frequency ω _p and the second frequency respectively. ω _s , where the third frequency ω _H = 2ω _s .

In the embodiment of the present invention, the models of other devices are not limited unless otherwise specified.

Any device that can perform the above functions can be used.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred embodiment, and the above-mentioned serial numbers of the embodiments of the present invention are only for description, and do not represent the advantages or disadvantages of the embodiments.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (7)

1. a high power high repetition frequency hundred picosecond laser, is characterized in that, described laser comprises: The seed laser emits seed light of the first frequency, and after passing through the first optical isolator, it enters a double-pass amplifier for amplification, and then passes through the first mirror, the first beam shaper, the first single-pass amplifier, the second mirror, and the first mirror in turn. After the three mirrors, the second beam shaper and the second optical isolator, enter the SBS pulse compressor to compress the first frequency seed light to the second frequency laser; The second frequency laser is sequentially amplified by a fourth mirror, a third beam shaper, several second single-pass amplifiers, a fifth mirror, a sixth mirror, a fourth beam shaper, and several four-pass slat amplifiers; The amplified laser passes through the seventh reflector, the fifth beam shaper, and the frequency multiplier to generate a third frequency laser, and finally outputs through a beam splitter. 2. The high-power high-repetition-frequency 100-picosecond laser according to claim 1, wherein the first optical isolator and the second optical isolator are composed of a first polarizer, a Faraday rotator, a first optical isolator, and a second optical isolator. It is composed of a half-wave plate, so that the incident seed light can pass through in one direction, and the reversely transmitted light is deflected and emitted when it passes through the first polarizer due to the change of the polarization state. 3. The high-power high-repetition-frequency 100-picosecond laser according to claim 1, wherein the double-pass amplifier is composed of a second polarizer, a first side pump module, and a first quarter-wave plate. It is composed of a zero-degree all-reflection mirror; The first quarter-wave plate is used to change the polarization state of the seed light; the zero-degree total reflection mirror is coated with a total reflection film for the first frequency seed light, and forms an included angle of 90° with the incident direction of the first frequency seed light to achieve Total reflection. 4. The high-power high-repetition-frequency 100-picosecond laser according to claim 1, wherein the first single-pass amplifier is composed of a second side pump module, a first 90° quartz rotor, a third side pump module composition. 5. a kind of high-power high repetition frequency hundred picosecond laser according to claim 1, is characterized in that, described SBS pulse compressor is composed of the third polarizer, the second quarter wave plate, the first focusing lens , composed of several Brillouin media; The second quarter-wave plate is used to change the laser polarization state after pulse compression; the first focusing lens focuses the incident seed light into the Brillouin medium; the first frequency seed light is in the horizontal polarization state and transmits into the third The polarizer is converted into elliptically polarized light through the second quarter-wave plate, and is focused into the Brillouin medium by the first focusing lens to generate the second frequency laser. After the second frequency laser is backscattered and pulse compressed, it passes through The first focusing lens and the second quarter-wave plate become vertically polarized, and finally the compressed laser light of the second frequency is reflected out of the SBS pulse compressor through the third polarizer. 6. The high-power high-repetition-frequency 100-picosecond laser according to claim 1, wherein the second single-pass amplifier is composed of a fourth side pump module, a second 90° quartz rotor, and a second focusing lens. , a first vacuum tube, a third focusing lens, a fifth side pump module, a second half-wave plate and a fourth polarizer, wherein the first vacuum tube is provided with a first aperture diaphragm; The second focusing lens, the first vacuum tube, the first aperture diaphragm and the third focusing lens together form a spatial filter, which is used to eliminate the spontaneous radiation amplification effect generated during the amplification process; the second half-wave plate and the fourth Polarizer combinations are used to control the laser output energy without changing the laser polarization state. 7. The high-power high-repetition-frequency 100-picosecond laser according to claim 1, wherein the four-way slab amplifier is composed of a fifth polarizer, a slab gain medium, an eighth mirror, a sixth Beam Shaper, Ninth Reflector, Tenth Reflector, Seventh Beam Shaper, Third Quarter-Wave Plate, Eleventh Reflector, Fourth Focusing Lens, Second Vacuum Tube, Fifth Focusing Lens, No. It is composed of a one-third wave plate, wherein a second aperture diaphragm is arranged in the second vacuum tube; The sixth beam shaper and the seventh beam shaper are composed of a single optical lens or optical lens group, and are used to shape the amplified seed beam to reduce the negative effect of reducing the amplification efficiency caused by the beam divergence; the third quarter-wave The mirror is used to change the polarization state of the laser during the amplification process; the eleventh mirror is coated with a total reflection film for the second frequency laser, and forms an angle of 90° with the incident direction of the second laser, so as to realize the full reflection of the second frequency laser reflection.

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