Wide-spectrum laser pulse energy amplification method

Abstract

The invention discloses a broadband spectrum laser pulse energy amplification method, and belongs to the technical field of ultrafast laser, and the method comprises the steps: sequentially carrying out the spectrum broadening, difference frequency and pulse time domain broadening of a titanium sapphire kilohertz laser pulse, and carrying out the pre-compensation of high-order dispersion introduced in the subsequent pulse energy amplification process; a double-chirp optical parametric amplification technology is utilized, a first wave band in the obtained infrared seed laser pulse is amplified to a first set value, a second wave band is pre-amplified to a second set value, and the first wave band is smaller than the second wave band; the chirped pulse amplification technology is utilized, a third wave band in the infrared seed laser pulse is amplified to a third set value, and the third wave band covers the long wave band in the first wave band and the second wave band; and performing pulse time domain compression on the output infrared seed laser pulse to obtain an infrared seed laser pulse with a near Fourier transform limit pulse width. According to the method, the high-peak-power single-optical-period infrared laser pulse can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrafast laser, and more specifically, relates to a method for amplifying the energy of a broadband laser pulse. Background Art

[0002] High-order Harmonic Generation (HHG) based on the interaction between femtosecond driving laser and atoms / molecules is an important way to generate attosecond pulses. The properties of the femtosecond driving laser largely determine the properties of the generated attosecond pulses. According to the three-step model theory of high-order harmonic generation, the cutoff photon energy of the high-order harmonic spectrum increases with the increase of the wavelength of the driving laser. On the other hand, in order to obtain isolated attosecond pulses, the electron recombination in the HHG process is restricted within half a cycle, which requires the driving laser to have a few optical cycle pulse width and the property of maintaining the stability of the Carrier to Envelope Phase (CEP). At present, isolated attosecond pulses driven by few optical cycle infrared lasers have been widely demonstrated by experiments, but the energy of the generated isolated attosecond pulses is less than picojoules (10 -12 J). In order to greatly improve the photon energy, pulse energy of isolated attosecond pulses and further shorten the pulse width of attosecond pulses, developing infrared lasers with higher pulse energy, shorter pulse width and CEP stability has become one of the research hotspots in the field of ultrafast optics.

[0003] Chirped Pulse Amplification (CPA) is the main technical means to obtain high-energy laser pulses. However, due to the limitation of the gain bandwidth of the laser gain crystal and the gain narrowing in the amplification process, it is difficult to obtain a wider bandwidth laser pulse amplification only by the CPA technology, and thus it is impossible to obtain few optical cycle infrared lasers. Optical Parameter Amplification (OPA) is the mainstream technical path to obtain few optical cycle infrared lasers. However, the damage threshold of the nonlinear crystal limits the further improvement of the energy.

[0004] Optical parametric chirped pulse amplification (OPCPA) and dual-chirped optical parametric amplification (DC-OPA) can effectively reduce the limitation of the crystal damage threshold on the output energy. By introducing chirp to the seed light, or simultaneously to the seed light and the pump light for pulse broadening, it is ensured that OPA and DC-OPA can perform the above-mentioned nonlinear frequency conversion process with higher pulse energy under the condition of the same peak power. It should be emphasized that the gain bandwidth of a single nonlinear crystal is limited, and it is difficult to directly obtain an optical-cycle laser pulse. Therefore, researchers have proposed a technical path of combining multiple nonlinear crystals to broaden the gain bandwidth, namely "Advanced DC-OPA". In 2024, based on the Advanced DC-OPA technology, researchers obtained an optical-cycle infrared laser pulse with a peak power of 6 TW and a single-pulse energy of 53 mJ. However, to obtain an infrared laser pulse energy of hundreds of millijoules or even higher, the inevitable parametric fluorescence effect in the DC-OPA process, the titanium-sapphire laser pump source with a higher single-pulse energy, etc. will be the limiting factors.

[0005] Generally speaking, the existing techniques for ultrafast infrared laser pulse amplification are difficult to directly amplify an optical-cycle infrared laser pulse and obtain a single-pulse energy exceeding hundreds of millijoules. Summary of the Invention

[0006] Aiming at the defects and improvement requirements of the existing technology, the present invention provides a method for amplifying the energy of a broadband laser pulse, aiming to solve the technical problem that the existing ultrafast infrared laser pulse amplification technology is difficult to directly amplify an optical-cycle infrared laser pulse and obtain a single-pulse energy exceeding hundreds of millijoules.

[0007] To achieve the above object, according to one aspect of the present invention, a method for amplifying the energy of a broadband laser pulse is provided, including: S1, performing spectral broadening and difference frequency on a titanium sapphire kHz laser pulse in sequence to obtain an infrared seed laser pulse; S2, performing pulse time-domain broadening on the infrared seed laser pulse and pre-compensating for the high-order dispersion introduced during the subsequent pulse energy amplification processes of S3 and S4; S3, using the double-chirped optical parametric amplification technique to amplify the first wavelength band in the infrared seed laser pulse output from S2 to a first set value and pre-amplify the second wavelength band to a second set value, where the first wavelength band is smaller than the second wavelength band, and the range of the second set value is 0.1 - 1 mJ; S4, using the chirped pulse amplification technique to amplify the third wavelength band in the infrared seed laser pulse output from S3 to a third set value, where the third wavelength band covers the long wavelength band in the first wavelength band and the second wavelength band; S5, performing pulse time-domain compression on the infrared seed laser pulse output from S4 to obtain an infrared seed laser pulse with a near Fourier transform-limited pulse width.

[0008] Further, in S1, the spectral range after spectral broadening is 500 - 1000 nm, and the spectral range after difference frequency is 1450 - 3000 nm.

[0009] Further, the first wavelength band is 1450 - 2400 nm, the second wavelength band is 2400 - 3000 nm, and the third wavelength band is 2200 - 3000 nm.

[0010] Further, in S3, using a BiBO crystal and adopting the double-chirped optical parametric amplification technique to amplify the first wavelength band in the infrared seed laser pulse output from S2 to a first set value; using an MgO:LN crystal and adopting the double-chirped optical parametric amplification technique to amplify the second wavelength band in the infrared seed laser pulse output from S2 to a second set value.

[0011] Further, in S4, using a Cr:ZnSe crystal and adopting the chirped pulse amplification technique to amplify the third wavelength band in the infrared seed laser pulse output from S3 to a third set value.

[0012] Further, in S2, using a chirped mirror to perform pulse time-domain broadening on the infrared seed laser pulse, and using an acousto-optic programmable dispersion filter to pre-compensate for the high-order dispersion introduced during the subsequent pulse energy amplification processes of S3 and S4.

[0013] Further, in S5, using a chirped mirror to perform pulse time-domain compression on the infrared seed laser pulse output from S4 to obtain an infrared seed laser pulse with a near Fourier transform-limited pulse width.

[0014] Further, in step S4, by using the two-pass chirped pulse amplification technology, the third wavelength band in the infrared seed laser pulse output from step S3 is amplified to a third set value; wherein, when the crystal energy storage reaches the peak value, the infrared seed laser pulse is injected, and the second-pass amplification is performed after a set time has elapsed since the completion of the first-pass amplification, and the set time is related to the crystal used in step S4.

[0015] Generally speaking, through the above technical solution conceived by the present invention, the following beneficial effects can be achieved:

[0016] (1) A method for amplifying the energy of a broadband spectral laser pulse is provided, which fully combines the advantages of wide gain bandwidth of DC-OPA and high amplification energy of CPA. The short wavelength band is amplified in the DC-OPA process, and the long wavelength band is amplified in the CPA process, and an extremely high peak power output with a bandwidth exceeding one octave and an energy exceeding 100 mJ can be obtained; according to theoretical calculations, the peak power of the mid-infrared laser pulse output by this method can exceed 20 TW, breaking the existing reported records, and obtaining a high peak power single optical cycle infrared laser pulse;

[0017] (2) In order to avoid excessive energy in the spectral overlap region (such as 2200 - 2400 nm) of the DC-OPA stage and the CPA stage, the second wavelength band (such as 2400 - 3000 nm) in the infrared seed laser pulse is pre-amplified in the DC-OPA stage, so as to obtain an ideal output spectrum; if the part of 2400 - 3000 nm is not pre-amplified, then the initial energy of the part of 2200 - 2400 nm in the CPA stage is much greater than that of 2400 - 3000 nm, resulting in this part obtaining most of the energy in the CPA process, and 2400 - 3000 nm cannot be amplified, and the output spectrum is not ideal;

[0018] (3) In order to obtain a single optical cycle infrared laser pulse, this method strictly controls the dispersion introduced into the laser pulse; specifically, the high-order dispersion mainly comes from the materials of the DC-OPA and CPA processes themselves, and this type of high-order dispersion is compensated by an acousto-optic programmable dispersion filter. For the requirement of the time-domain broadening of the laser pulse during the amplification process, chirped mirrors are used to provide second-order dispersion, realizing the time-domain compression of the laser pulse after time-domain broadening before amplification. Description of the Drawings

[0019] Figure 1 It is a flowchart of the method for amplifying the energy of a broadband spectral laser pulse provided by an embodiment of the present invention;

[0020] Figure 2A It is a phase matching efficiency diagram of difference frequency based on a BiBO crystal for a pulse with a spectral width of 500 - 1000 nm;

[0021] Figure 2BThe Fourier transform-limited pulse corresponding to the broadband infrared seed laser pulse obtained by difference frequency;

[0022] Figure 3A The phase matching efficiency diagrams based on the BiBO crystal for amplifying the 1450 - 2400 nm band and based on the MgO:LN crystal for preventing the 2400 - 3000 nm band;

[0023] Figure 3B The predicted output result after the seed light passes through double chirped optical parametric amplification and pre-amplification;

[0024] Figure 3C The simulated output result after the seed light passes through two-pass chirped pulse amplification;

[0025] Figure 3D The schematic diagram of the crystal energy storage change during the amplification process;

[0026] Figure 4A The pulse broadening effect after the initial seed light introduces about 4500 fs 2 group delay dispersion through the chirped mirror;

[0027] Figure 4B The spectral phase after the double chirped optical parametric amplification and chirped pulse amplification process;

[0028] Figure 4C The spectral phase corresponding to the residual dispersion after using the chirped mirror to make the second-order dispersion zero;

[0029] Figure 4D For Figure 4C The time-domain pulse obtained after performing the inverse Fourier transform on the spectral phase in

[0030] Figure 5 The schematic diagram of the system structure for obtaining mid-infrared single-cycle pulses with high peak power provided by the embodiments of the present invention. Detailed implementation manners

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence.

[0033] Figure 1The flowchart of the wide-spectrum laser pulse energy amplification method provided by the embodiments of the present invention. Refer to Figure 1 , in combination with Figures 2A - 5 , the wide-spectrum laser pulse energy amplification method in this embodiment is described in detail. The method includes operations S1 - S5.

[0034] Operation S1: Spectrally broaden and difference-frequency the titanium-sapphire kHz laser pulse in sequence to obtain an infrared seed laser pulse.

[0035] In operation S1, for example, use an air-core fiber to spectrally broaden the titanium-sapphire kHz laser pulse (750 - 850 nm), and the broadened spectral range is 500 - 1000 nm. Based on the bismuth borate (BiBO) crystal, difference-frequency the laser pulse output after broadening, and then obtain an infrared seed laser pulse with a spectral range of 1450 - 3000 nm. The seed light is generated by difference-frequency of the laser pulse with a wavelength range of 500 - 1000 nm, and its spectral range is about 1450 - 3000 nm, exceeding one octave.

[0036] Operation S2: Temporally broaden the infrared seed laser pulse, and pre-compensate the high-order dispersion introduced in the subsequent pulse energy amplification processes of operations S3 and S4.

[0037] According to the embodiments of the present invention, in operation S2, use a chirped mirror to temporally broaden the infrared seed laser pulse, and use an acousto-optic programmable dispersive filter (Dazzler) to pre-compensate the high-order dispersion (third-order dispersion, fourth-order dispersion, etc.) introduced in the subsequent pulse energy amplification process, ensuring that operation S5 can completely compensate for the dispersion and obtain a pulse width close to the Fourier transform limit.

[0038] Operation S3: Use the dual-chirped optical parametric amplification technology to amplify the first wavelength band in the infrared seed laser pulse output by operation S2 to a first set value and pre-amplify the second wavelength band to a second set value. The first wavelength band is smaller than the second wavelength band, and the range of the second set value is 0.1 - 1 mJ.

[0039] Preferably, in this embodiment, the first wavelength band is 1450 - 2400 nm, the second wavelength band is 2400 - 3000 nm, and the third wavelength band is 2200 - 3000 nm. Use the BiBO crystal and adopt the dual-chirped optical parametric amplification technology to amplify the first wavelength band in the infrared seed laser pulse output by S2 to the first set value; use the MgO:LN crystal and adopt the dual-chirped optical parametric amplification technology to amplify the second wavelength band in the infrared seed laser pulse output by S2 to the second set value.

[0040] Specifically, based on the BiBO crystal, the double-chirped optical parametric amplification technology is adopted to amplify the 1450 - 2400 nm band in the infrared seed laser pulse output by operation S2, obtaining a pulse energy of approximately 40 mJ in the 1450 - 2400 nm band; based on the MgO:LN crystal, the double-chirped optical parametric amplification technology is adopted to amplify the 2400 - 3000 nm band in the infrared seed laser pulse output by operation S2, obtaining a pulse energy of approximately 0.5 mJ in the 2400 - 3000 nm band; finally, a pulse energy of approximately 40 mJ in the 1450 - 2400 nm band and approximately 0.5 mJ in the 2400 - 3000 nm band, totaling approximately 40.5 mJ, is obtained.

[0041] Operation S4 uses the chirped pulse amplification technology to amplify the third band in the infrared seed laser pulse output by operation S3 to a third set value. The third band covers the long wavelength band in the first band and the second band.

[0042] Preferably, in operation S4, using the Cr:ZnSe crystal and the chirped pulse amplification technology, the third band in the infrared seed laser pulse output by operation S3 is amplified to the third set value.

[0043] For example, using the Cr:ZnSe crystal and the chirped pulse amplification technology, the 2200 - 3000 nm band in the infrared seed laser pulse output by operation S3 is amplified, and finally a pulse energy of approximately 200 mJ in the entire 1450 - 3000 nm band is obtained.

[0044] Preferably, in operation S4, the two-pass chirped pulse amplification technology is used to amplify the third band in the infrared seed laser pulse output by operation S3 to the third set value. Among them, the infrared seed laser pulse is injected when the crystal energy storage reaches the peak value, and the second pass amplification is carried out after a set time after the first pass amplification is completed. The set time is related to the crystal used in S4.

[0045] Operation S5 performs pulse temporal compression on the infrared seed laser pulse output by operation S4 to obtain an infrared seed laser pulse with a near Fourier transform limited pulse width.

[0046] Preferably, a chirped mirror is used to perform pulse temporal compression on the infrared seed laser pulse output by operation S4 to obtain an infrared seed laser pulse with a near Fourier transform limited pulse width.

[0047] It should be noted that the specific values of the broadened infrared seed laser pulse, the first band, the second band, the third band, the first set value, the second set value, and the third set value in the above embodiments are all one example, and can also be other values, which are applicable to other scenarios.

[0048] The following describes the specific process of the broadband laser pulse energy amplification method in conjunction with a specific example, including the following steps.

[0049] Step 1: Use an air-core fiber to broaden the spectrum of a Ti:sapphire kHz laser pulse. The broadened spectrum range is approximately 500 - 1000 nm.

[0050] The single-pulse energy output by the Ti:sapphire kHz is approximately 1 mJ, and the efficiency of the air-core fiber is approximately 70%.

[0051] Step 2: Based on a BiBO crystal, perform difference frequency on the laser pulse output in Step 1, and then obtain an infrared seed laser pulse with a spectrum range of approximately 1450 - 3000 nm.

[0052] In this embodiment, the BiBO cutting angle is approximately 63°, and the thickness is approximately 0.3 mm. The difference frequency effect is as Figure 2A and Figure 2B shown. Refer to Figure 2A , which shows the phase matching efficiency diagram of a pulse with a spectral width of 500 - 1000 nm based on a BiBO crystal for difference frequency. The phase matching angle is approximately 63°; refer to Figure 2B , which shows the Fourier transform-limited pulse corresponding to the broadband infrared seed laser pulse obtained by difference frequency. The spectrum of the seed laser pulse is 1450 - 3000 nm.

[0053] Step 3: Based on chirped mirrors and an acousto-optic programmable dispersive filter, introduce dispersion to the infrared seed laser pulse output in Step 2, perform pulse temporal broadening, and simultaneously pre-compensate for the high-order dispersion introduced during the amplification process.

[0054] In this embodiment, due to the inevitable losses introduced by chirped mirrors and Dazzler, according to estimates, the total energy of the seed light finally entering the amplification stage is approximately 20 nJ.

[0055] The dispersion control effect after adopting this method is as Figures 4A - 4D shown. Figure 4A is the pulse broadening effect after the initial seed light introduces approximately 4500 fs 2 group delay dispersion through a chirped mirror. The full width is approximately 4 ps; Figure 4B is the spectral phase after the DC-OPA and CPA processes; Figure 4C is the spectral phase corresponding to the residual dispersion after compensating the second-order dispersion to zero using a chirped mirror; Figure 4D is Figure 4C the temporal pulse obtained by performing an inverse Fourier transform on the spectral phase in

[0056] Step 4: Based on the BiBO crystal, using the DC-OPA technology, amplify the 1450 - 2400 nm band in the infrared seed laser pulse output in Step 3 to obtain a pulse energy of approximately 40 mJ in the 1450 - 2400 nm band.

[0057] Figures 3A - 3D The amplification effect diagram of the ultrashort pulse is shown. Figure 3A It is the phase matching efficiency diagram for amplifying the 1450 - 2400 nm band based on the BiBO crystal and preventing the phase matching of the large 2400 - 3000 nm band based on the MgO:LN crystal. Among them, θ is the phase matching angle and α is the non-collinear angle. Figure 3B It is the estimated output result after the seed light is amplified by DC-OPA and pre-amplified. Among them, the energy in the 1450 - 2400 nm band is approximately 40 mJ, and the energy in the 2400 - 3000 nm band is approximately 0.5 mJ. Figure 3C It is the simulated output result of the seed light after two-pass CPA amplification. After the first-pass amplification, the total energy of the laser pulse increases from 40.5 mJ to 73.22 mJ. After the second-pass amplification, the total energy of the laser pulse increases to 229.69 mJ. There is partial loss of the short-wave band energy, which is caused by the short-wave band being within the absorption spectrum range of the gain medium Cr:ZnSe crystal used in the CPA process. Figure 3D It is the schematic diagram of the crystal energy storage change during the amplification process. We inject the seed light when the energy storage reaches the peak, and at the same time, the second-pass amplification is carried out approximately 10 ns after the first-pass amplification to ensure that a large amount of short-wave band energy is not absorbed.

[0058] Step 5: Based on the MgO:LN crystal, using the DC-OPA technology, pre-amplify the 2400 - 3000 nm band in the infrared laser pulse output in Step 4 to obtain approximately 40 mJ in the 1450 - 2400 nm band and approximately 0.5 mJ in the 2400 - 3000 nm band, with a total pulse energy of approximately 40.5 mJ.

[0059] In this embodiment, the phase matching methods in Step 4 and Step 5 are both non-collinear type-I phase matching, as Figure 3A shown. Among them, the cutting angle of the BiBO crystal is 10.76°, the non-collinear angle is 0.85°, the cutting angle of the MgO:LN crystal is 48.4°, the non-collinear angle is 1°, and the phase matching bandwidth covers the entire wavelength band of the seed light. Refer to Figure 5 , and adopt a three-stage amplification method. The same phase matching method is used for each stage of amplification. The first two stages of DC-OPA use a combination of BiBO crystal and MgO:LN crystal. In order to reduce the absorption loss of the BiBO crystal to the long-wave band, the BiBO crystal is in the front and the MgO:LN crystal is in the back.

[0060] In this example, the pump in the DC-OPA stage comes from the 5 Hz laser pulses (750 - 850 nm) of a 50 TW titanium sapphire laser, with a total energy of approximately 300 mJ. The total energies of the first two-stage pumps are 1.5 mJ and 30 mJ respectively. The energies of the two-stage pumps distributed to the BiBO crystal are 1 mJ and 25 mJ respectively, and the energies of the two-stage pumps distributed to the MgO:LN crystal are 0.5 mJ and 5 mJ respectively. The third-stage amplification is a BiBO single crystal with a total pump energy of 270 mJ. After three-stage DC-OPA, the total energy of the seed light single pulse is approximately 40.5 mJ, about 40 mJ in the short wavelength band, and about 0.5 mJ in the long wavelength band.

[0061] Step 6: Based on the Cr:ZnSe crystal, using the CPA technology, amplify the 2200 - 3000 nm band in the infrared laser pulse output in Step 5, and finally obtain a pulse energy of approximately 200 mJ for the entire 1450 - 3000 nm band.

[0062] In this embodiment, the doping concentration of the utilized Cr:ZnSe crystal is approximately 6×10 18 cm -3 , with a size of 16.8×16.8×6.8 mm. The pump light comes from a 2000 nm Q-switched laser. In order to effectively suppress the short-wavelength energy loss caused by ground-state stimulated absorption, the pump power needs to be large enough to pump as many ground-state particles as possible to the upper energy level before the seed light hits the crystal. Therefore, the total energy of the Q-switched laser in this example is set to 2 J, and the pulse width is approximately 20 ns. After two-pass amplification of the seed light, the total energy is approximately 229.69 mJ, and the short-wavelength energy loss is approximately 5 mJ, which is within an acceptable range. The change in the seed light intensity during the two-stage amplification process is shown in Figure 3C .

[0063] Step 7: Based on the chirped mirror, perform pulse temporal compression on the output pulse of Step 6 to obtain a pulse width close to the Fourier transform limit.

[0064] In this example, it is estimated that the compression efficiency of the chirped mirror is greater than 70%, that is, the final output single pulse energy is greater than 160 mJ.

[0065] The wide-spectrum laser pulse energy amplification method provided by the embodiment of the present invention combines double chirped optical parametric amplification and chirped pulse amplification to obtain a single optical cycle infrared laser pulse with a high peak power. During the implementation of this method, the dispersion is strictly controlled. The second-order dispersion is compensated by a chirped mirror, and the higher-order dispersion is compensated by an acousto-optic programmable dispersion filter, which can achieve complete compensation of the dispersion and obtain a single optical cycle laser pulse. This method can obtain high energy and short pulse width, that is, a single optical cycle infrared laser pulse with a high peak power, and it is an ultrafast laser amplification technology with higher gain and wider gain bandwidth.

[0066] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for amplifying the energy of a wide spectrum laser pulse, characterized in that: include: S1, sequentially perform spectrum broadening and frequency difference on the Ti:Sapphire kilohertz laser pulse to obtain an infrared seed laser pulse; S2, performing pulse time domain broadening on the infrared seed laser pulse, and pre-compensating for the high-order dispersion introduced in the subsequent S3 and S4 pulse energy amplification processes; S3, using double chirp optical parametric amplification technology, amplifying the first band of the infrared seed laser pulse output by S2 to a first set value, and pre-amplifying the second band to a second set value, wherein the first band is smaller than the second band, and the second set value ranges from 0.1 to 1 mJ; S4, using chirped pulse amplification technology to amplify the third wavelength band of the infrared seed laser pulse output by S3 to a third set value, wherein the third wavelength band covers the long wavelength band in the first wavelength band and the second wavelength band; S5, performing pulse time domain compression on the infrared seed laser pulse output by S4 to obtain an infrared seed laser pulse with a pulse width close to the Fourier transform limit.

2. The method for amplifying wide spectrum laser pulse energy according to claim 1, characterized in that: The spectrum range after spectrum broadening in S1 is 500-1000nm, and the spectrum range after difference frequency is 1450-3000nm.

3. The method for amplifying wide spectrum laser pulse energy according to claim 2, characterized in that: The first waveband is 1450-2400nm, the second waveband is 2400-3000nm, and the third waveband is 2200-3000nm.

4. The method for amplifying wide spectrum laser pulse energy according to claim 3, characterized in that: In S3, a BiBO crystal is used to adopt a double-chirped optical parametric amplification technology to amplify the first wavelength band of the infrared seed laser pulse output by S2 to a first set value; MgO:LN crystal is used and double-chirp optical parametric amplification technology is adopted to amplify the second band of the infrared seed laser pulse output by S2 to a second set value.

5. The method for amplifying wide spectrum laser pulse energy according to claim 3, characterized in that: In S4, Cr:ZnSe crystal is used to adopt chirped pulse amplification technology to amplify the third band of the infrared seed laser pulse output by S3 to a third set value.

6. The method for amplifying wide spectrum laser pulse energy according to any one of claims 1 to 5, characterized in that: In S2, a chirped mirror is used to perform pulse time domain broadening on the infrared seed laser pulse, and an acousto-optic programmable dispersion filter is used to pre-compensate for high-order dispersion introduced in the subsequent S3 and S4 pulse energy amplification processes.

7. The method for amplifying wide spectrum laser pulse energy according to any one of claims 1 to 5, characterized in that: In S5, a chirped mirror is used to perform pulse time domain compression on the infrared seed laser pulse output by S4 to obtain an infrared seed laser pulse with a pulse width close to the Fourier transform limit.

8. The method for amplifying wide spectrum laser pulse energy according to any one of claims 1 to 5, characterized in that: In S4, a third wavelength band of the infrared seed laser pulse outputted by S3 is amplified to a third set value by using a two-pass chirped pulse amplification technology; When the crystal energy storage reaches a peak value, an infrared seed laser pulse is injected, and after a set time has passed since the first-pass amplification is completed, a second-pass amplification is performed, and the set time is related to the crystal used in S4.

Images