Chirped pulse stretching and compressing device and amplification system

Abstract

The application discloses a chirp pulse stretching and compressing device and an amplification system, and relates to the field of lasers. The chirp pulse stretching and compressing device comprises a first polarization beam splitter prism, a pulse stretching and compressing device and a dispersion regulator. The chirp pulse stretching and compressing device has a stretching port and a compressing port arranged oppositely, is divided into a stretching light path part and a compressing light path part, the two light path parts share one main stretching and compressing module, and the stretching light path part is additionally provided with a dispersion regulator to provide adjustable and additional dispersion compensation. The chirp pulse stretching and compressing device provided by the application can be flexibly adapted to different amplification systems, so that the output light pulse reaches near-zero chirp and ultra-short pulse width is realized.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a chirped pulse broadening and compression device and amplification system. Background Technology

[0002] Femtosecond lasers are characterized by high peak power and extremely short pulse widths, enabling low thermal impact and high-quality precision micromachining of metals and various brittle materials. With the continuous development of process technology in recent years, they have broad application prospects in the industrial field. Current commercial high-power femtosecond lasers are typically implemented using chirped pulse amplification (CPA) technology. Its basic structure and principle are as follows: a femtosecond seed source generates an ultrashort pulse laser sequence with a fixed repetition rate. This sequence is then stretched in the time domain to tens of picoseconds to several nanoseconds by a pulse stretcher with significant second-order dispersion. A pulse selector then down-converts the pulse frequency or outputs a pulse train. A multi-stage power amplifier enhances the average power and single-pulse energy. Finally, a pulse compressor compensates for dispersion to achieve ultrashort pulse output in the femtosecond or picosecond range.

[0003] However, current femtosecond pulsed CPA lasers employ a pulse stretching-compression scheme using a chirped volume bragg grating (CVBG) as the stretcher / compressor. A CVBG is a chirped grating structure etched on a photorefractive crystal. By using a CVBG as both a stretcher and a compressor, and allowing the seed light and the amplified laser to be incident in opposite directions, their dispersion processes within the CVBG are exactly opposite and can compensate for each other. However, the dispersion of this scheme cannot be adjusted, and it cannot compensate for additional material dispersion in the amplification path or optimize the compression effect, resulting in the final output pulse width not reaching its minimum value. Summary of the Invention

[0004] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and to provide a chirped pulse broadening compression device.

[0005] This application provides:

[0006] A chirped pulse broadening and compression device, comprising:

[0007] The first polarizing beam splitter has a first port, a second port, a third port, and a fourth port;

[0008] A pulse stretching and compression device has a stretching port for receiving an optical pulse to be stretched and a compression port for receiving an optical pulse to be compressed, which are disposed opposite to each other, the stretching port being disposed on one side of the fourth port;

[0009] A dispersion modulator, disposed on one side of the third port, is used to provide group delay dispersion for the light pulse emitted through the third port;

[0010] The seed pulse enters the first polarization beam splitter through the first port and exits from the third port. After entering the dispersion modulator, it is reflected back along the original path, enters the first polarization beam splitter again through the third port, and then enters the pulse stretching compressor through the fourth port. After time-domain stretching in the pulse stretching compressor, it exits sequentially through the fourth port, the first polarization beam splitter, and the second port.

[0011] In addition, the chirped pulse broadening and compression device according to this application may also have the following additional technical features:

[0012] In some embodiments of this application, the dispersion modulator includes:

[0013] The dispersive element is one of a chirped grating pair, a chirped mirror, a chirped mirror group, or a prism pair;

[0014] A reflector is disposed on the side of the dispersive element opposite to the third port.

[0015] In some embodiments of this application, the chirped pulse broadening and compression device further includes an electrically controlled displacement stage. When the dispersive element is a grating pair or a prism pair, the dispersive element is mounted on the electrically controlled displacement stage. The electrically controlled displacement stage is used to adjust the distance between the two gratings in the grating pair or the distance between the two prisms in the prism pair.

[0016] In some embodiments of this application, the dispersive element is a chirped grating pair, wherein the two gratings in the grating pair are parallel to each other.

[0017] In some embodiments of this application, the reflector causes the incident light to pass through the grating pair or prism pair again and return to the third port along the original path.

[0018] In some embodiments of this application, a first waveplate is provided at the first port, a second waveplate is provided between the third port and the dispersion modulator, and a third waveplate is provided between the fourth port and the widening port.

[0019] In some embodiments of this application, the first waveplate is a 1 / 2 waveplate, and the second and third waveplates are both 1 / 4 waveplates.

[0020] In some embodiments of this application, the chirped pulse broadening and compression device further includes a second polarizing beam splitter, the second polarizing beam splitter having a fifth port, a sixth port and a seventh port, the sixth port and the seventh port being located on two opposite sides of the second polarizing beam splitter, the sixth port being correspondingly disposed to the compression port, and a fourth waveplate being disposed between the compression port and the sixth port, and a fifth waveplate being disposed at the fifth port;

[0021] The amplified beam enters from the compression input end, passes through the fifth waveplate and the second polarizing beam splitter, and exits perpendicular to the incident beam. It then enters the pulse broadening compressor from the sixth port for compression, passes through the fourth waveplate and the second polarizing beam splitter again, and exits from the seventh port.

[0022] In some embodiments of this application, the fourth waveplate is a quarter waveplate and the fifth waveplate is a half waveplate.

[0023] In some embodiments of this application, the pulse broadening compressor is a chirped volume grating.

[0024] This application also provides an amplification system, including the chirped pulse broadening and compression device described in any of the above embodiments.

[0025] Compared to existing technologies, the advantages of this application are as follows: This application proposes a chirped pulse stretching and compression device. Through the configuration of a dispersion modulator and a first polarizing beam splitter, the seed pulse enters the first polarizing beam splitter through the first port and exits from the third port. After entering the dispersion modulator, it is reflected back along the original path, enters the first polarizing beam splitter again through the third port, and then enters the pulse stretching and compression device through the fourth port. Within the pulse stretching and compression device, the pulse is stretched in the time domain and then exits sequentially through the fourth port, the first polarizing beam splitter, and the second port. Compared to existing solutions that use a single CVBG as both a stretcher and a compressor, the stretching and compression device provided by this application overcomes the shortcomings of unadjustable dispersion and uncompensated additional dispersion in the amplification link. This allows the final output optical pulse width to reach the femtosecond level, and the pulse width can also be adjusted according to application requirements. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a chirped pulse broadening and compression apparatus in some embodiments of this application is shown;

[0028] Figure 2 A schematic diagram is shown of a chirped pulse broadening and compression device in some embodiments of this application, in which the dispersive element is a pair of transmission gratings;

[0029] Figure 3 A schematic diagram is shown of a chirped pulse broadening and compression device in some embodiments of this application, in which the dispersive element is a pair of reflective gratings;

[0030] Figure 4 A schematic diagram of one embodiment of the pulse broadening compressor in the chirped pulse broadening compressor apparatus of this application is shown;

[0031] Figure 5 A schematic diagram of the amplification system in some embodiments of this application is shown.

[0032] Explanation of key component symbols:

[0033] 100 - Chirped pulse broadening and compression device; 110 - First polarizing beam splitter prism; 111 - First port; 112 - Second port; 113 - Third port; 114 - Fourth port; 120 - Second polarizing beam splitter prism; 121 - Fifth port; 122 - Sixth port; 123 - Seventh port; 130 - Pulse broadening and compression unit; 131 - Broadening port; 132 - Compression port; 140 - Dispersion modulator; 141 - Dispersion element; 1411 - Grating pair; 14111 - Grating; 142 - Mirror; 150 - First waveplate; 151 - Second waveplate; 152 - Third waveplate; 153 - Fourth waveplate; 154 - Fifth waveplate; 200 - Amplification system; 210 - Preamplifier; 220 - Frequency selector; 230 - Multistage amplifier; 300 - Femtosecond seed laser. Detailed Implementation

[0034] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] In related technologies, a CVBG is used as both a stretcher and a compressor, with the seed light and the amplified laser incident in opposite directions. This results in opposite dispersion processes within the CVBG, allowing for mutual compensation. However, this approach lacks adjustable dispersion and cannot optimize compression, preventing the final output pulse width from reaching its minimum. For example, in a high-power fiber femtosecond amplification system at the 1µm wavelength, the material dispersion of the fiber at this wavelength is approximately 0.02 ps.2 / m, assuming the total length of the fiber optic link is 10m and the spectral bandwidth of the laser is 10nm, the final output pulse width is approximately 3.5ps, while the width of the Fourier transform-restricted pulse is approximately 160fs, the pulse width increases by nearly 20 times, and the peak power of the pulse is greatly reduced.

[0040] To solve the above problems, such as Figures 1 to 4 As shown, an embodiment of this application provides a chirped pulse broadening and compression device 100, mainly installed in the amplification system 200, to realize the functions of broadening and compression in the laser. The chirped pulse broadening and compression device 100 includes a first polarizing beam splitter 110, a pulse broadening and compression unit 130, and a dispersion modulator 140.

[0041] See also Figure 1 The first polarizing beam splitter 110 has a first port 111, a second port 112, a third port 113, and a fourth port 114. Optionally, the first port 111 and the third port 113 are located on opposite sides of the first polarizing beam splitter 110, and the second port 112 and the fourth port 114 are located on opposite sides of the first polarizing beam splitter 110. Furthermore, the first port 111, the second port 112, the third port 113, and the fourth port 114 are not on the same side of the first polarizing beam splitter 110.

[0042] The pulse stretching compressor 130 has a stretching port 131 for receiving optical pulses to be stretched and a compression port 132 for receiving optical pulses to be compressed, which are disposed opposite to each other. The stretching port 131 is disposed on one side of the fourth port 114.

[0043] The dispersion modulator 140 is disposed on one side of the third port 113 and is used to provide group delay dispersion for the light pulse emitted through the third port 113.

[0044] The seed pulse enters the first polarizing beam splitter 110 through the first port 111 and exits from the third port 113. After entering the dispersion modulator 140, it is reflected back along the original path, enters the first polarizing beam splitter 110 again through the third port 113, and then enters the pulse broadening compressor 130 through the fourth port 114. After being broadened in the pulse broadening compressor 130 in the time domain, it is emitted sequentially through the fourth port 114, the first polarizing beam splitter 110, and the second port 112.

[0045] It should be noted that the seed pulse can be emitted by a femtosecond seed laser 300. If an all-fiber mode-locked pulsed fiber laser is selected, a stable femtosecond laser pulse signal, i.e., the seed pulse, can be obtained. The arrows indicate the optical path of the light pulse.

[0046] like Figure 2 As shown, assuming the center wavelength of the femtosecond laser pulse signal emitted by the femtosecond seed laser 300 is 1030nm, the bandwidth is 10nm, and the total length of the fiber amplification link is 10m, then the material dispersion that needs to be compensated is 0.2ps. 2 If the dispersion modulator 140 uses a transmission grating pair with a grating constant of 1000 l / mm, the group delay dispersion (GDD) of the transmission grating pair is calculated according to the formula:

[0047]

[0048] Where N is the number of passes of the transmission grating pair (N = 2 in this example), m is the diffraction order (-1), λ is the center wavelength of the laser, L is the vertical spacing between the transmission grating pairs, d is the grating period, c is the speed of light, and θ... i θ is the angle of incidence, usually Littoral angle, in this example θ i The angle is 31°. Therefore, in this chirped pulse stretching and compression device 100, only a 33mm grating spacing is needed to pre-compensate for the dispersion of the amplification link. This results in a short optical path, a small spot size, and relatively low signal power. Small-area diffraction gratings can be used, making it less expensive than using chirped fiber gratings (CFBGs) as stretchers. Furthermore, it offers greater flexibility, a compact structure, and higher reliability. In addition, in the high-power fiber amplification system 200, the dispersion modulator 140 can also pre-compensate to some extent for the nonlinear phase shift caused by self-phase modulation (SPM) that may occur during the amplification process, thereby adjusting the dispersion and improving the quality of the output pulse.

[0049] Of course, in other embodiments, the parameters in the above formula can be selected with other values.

[0050] Compared with existing solutions that use a single CVBG as both a stretcher and compressor, the chirped pulse stretching and compression device 100 provided in this application overcomes the shortcomings of unadjustable dispersion and uncompensated additional dispersion in the amplification link. This allows the final output pulse width to reach the femtosecond level, and the pulse width can be adjusted according to the application requirements. It can be flexibly adapted to different amplification systems 200, enabling the output optical pulse to achieve near-zero chirp and realize ultra-short pulse width.

[0051] In some embodiments of this application, the dispersion modulator 140 may optionally include a dispersion element 141 and a reflector 142.

[0052] The dispersive element 141 is one of a grating pair 1411, a chirped mirror, a group of chirped mirrors, or a prism pair.

[0053] The grating pair 1411 can use a reflective grating (such as...) Figure 3 As shown,) or a transmissive grating (such as...) Figure 2 As shown, the diffraction grating has different diffraction angles for different wavelength components of the incident light, introducing angular dispersion. After the light passes through the grating, it has a gradually changing group delay within its spectral bandwidth. Figure 2 The example shown is a reflective grating pair.

[0054] Because chirped mirrors have spatially varying structures, light of different wavelengths enters the mirror structure at different depths, resulting in different group delays.

[0055] Of course, in other embodiments, the dispersive element 141 may also be selected as a pair of prisms for dispersion to achieve group delay dispersion.

[0056] A reflector 142 is disposed on the side of the dispersive element 141 opposite to the third port. Thus, the light beam entering the dispersive element 141 is reflected by the reflector 142 and returns along its original path to the third port 113. The reflector 142 is preferably a total internal reflection mirror.

[0057] In some embodiments of this application, optionally, the chirped pulse broadening and compression device 100 further includes an electrically controlled displacement stage. When the dispersive element 141 is a grating pair 1411 or a prism pair, the dispersive element 141 is mounted on the electrically controlled displacement stage. The electrically controlled displacement stage is used to adjust the distance between the two gratings 14111 in the grating pair 1411 or the distance between the two prisms in the prism pair.

[0058] In this embodiment, the distance between the two gratings 14111 and the distance between the two prisms are adjusted by setting the electronically controlled displacement stage to achieve functions such as online adjustment of the output pulse width.

[0059] Combination Figure 2 As shown, in the above embodiment, specifically, the dispersive element 141 is a grating pair 1411, in which the two gratings 14111 are parallel to each other. Alternatively, the dispersive element 141 is a prism pair.

[0060] Specifically, incident light pulses with a certain spectral bandwidth undergo spectral dispersion after being diffracted by a grating or refracted by a prism. Light components of different wavelengths are separated in space. When they exit through the grating pair or prism pair, they reassemble in the same direction in space. However, because the light pulses of different wavelengths travel different optical paths, some components travel shorter paths and are at the leading edge of the pulse, while others travel longer paths and are at the trailing edge. The resulting light pulses form a chirp.

[0061] Of course, in other embodiments, the dispersive element 141 may also be a chirped mirror assembly.

[0062] like Figure 1 As shown, in some embodiments of this application, a first waveplate 150 is provided at the first port 111, a second waveplate 151 is provided between the third port 113 and the dispersion modulator 140, and a third waveplate 152 is provided between the fourth port 114 and the widening port 131.

[0063] Specifically, the first waveplate 150 is a half-wave plate, and the second waveplate 151 and the third waveplate 152 are both quarter-wave plates.

[0064] In this embodiment, for example, a linearly polarized light pulse is incident along the first port 111, passes through a half-wave plate (first wave plate 150) and becomes polarized along the P direction, then is transmitted through the first polarizing beam splitter 110. After passing through a quarter-wave plate (second wave plate 151), it becomes circularly polarized light. After diffraction by a pair of transmission gratings with the same parameters (grating period), it forms a broadly elliptical light pulse with spatial dispersion, which is then incident perpendicularly onto the reflector 142. It is reflected by the reflector 142 and returns along the original path. Then, the light pulse passes through the quarter-wave plate (second wave plate 151) again and becomes S-light with a polarization direction perpendicular to the incident direction. Therefore, when it is incident again on the first polarizing beam splitter 110, it is reflected, passes through another quarter-wave plate (third wave plate 152) and becomes circularly polarized light. Then, it is incident into the CVBG along the direction of the grating period's density. The long-wavelength component of the light pulse is reflected at the forward position, and the short-wavelength component is reflected at the rear position. Therefore, the output light pulse has a positive chirp and is broadened in the time domain. After passing through the first polarization beam splitter 110 again, it is output from the fourth port 114, that is, from the broadened output end.

[0065] like Figure 1 As shown, in some embodiments of this application, the chirped pulse broadening and compression device 100 further includes a second polarizing beam splitter 120. The second polarizing beam splitter 120 has a fifth port 121, a sixth port 122, and a seventh port 123. The sixth port 122 and the seventh port 123 are located on two opposite sides of the second polarizing beam splitter 120. The sixth port 122 is correspondingly disposed with respect to the compression port 132, and a fourth waveplate 153 is disposed between the compression port 132 and the sixth port 122. A fifth waveplate 154 is disposed at the fifth port 121.

[0066] The amplified beam enters from the compression input end. After passing through the fifth waveplate 154, its polarization direction is perpendicular to the transmission polarization direction of the second polarizing beam splitter 120. Therefore, it is reflected by the beam splitting surface of the second polarizing beam splitter 120. The outgoing beam is perpendicular to the incoming beam and enters the pulse broadening compressor 130 from the sixth port 122 through the fourth waveplate 153 for compression. After being compressed again, it passes through the fourth waveplate 153, and its polarization direction becomes the same as the transmission polarization direction of the second polarizing beam splitter 120. It then exits from the seventh port 123.

[0067] Specifically, the fourth waveplate 153 is a quarter waveplate, and the fifth waveplate 154 is a half waveplate.

[0068] In this embodiment, the amplified laser light is incident from the compression input end (i.e., the fifth port 121), passes through a half-wave plate (the fifth wave plate 154) and is polarized along the S direction. It is then incident on the second polarizing beam splitter 120 and reflected. After passing through a quarter-wave plate (the fourth wave plate 153), it becomes circularly polarized light. Then, it is incident on the CVBG along the periodic dense-sparse direction of the grating 14111. The positive chirp originally present in the light pulse reflected and output by the CVBG is compensated and compressed in the time domain. It passes through the quarter-wave plate (the fourth wave plate 153) again and becomes P-polarized light. Finally, it is output through the seventh port 123 of the second polarizing beam splitter 120, i.e., output from the compression output end.

[0069] It should be noted that when light is incident on the surface of an optical element, the coordinate system used is defined by the plane containing the incident and reflected beams. If the polarization vector of the light is in this plane, it is called P-polarization, and if the polarization vector is perpendicular to the plane, it is called S-polarization.

[0070] like Figure 4 As shown, in the above embodiments of this application, the pulse broadening compressor 130 is a chirped volume grating. In this embodiment, the use of a chirped volume grating simplifies the structure, reduces cost, and significantly reduces the size / footprint of the laser using this product.

[0071] like Figure 5 As shown, embodiments of this application also provide an amplification system 200, including the chirped pulse broadening and compression device 100 described in any of the above embodiments.

[0072] Optionally, the amplification system 200 further includes a preamplifier 210, a frequency selector 220, and a multistage amplifier 230. In this embodiment, the preamplifier 210 and the multistage amplifier 230 can be solid-state laser amplifiers using laser crystals, fiber amplifiers using doped gain fibers, or a combination of both.

[0073] Frequency selector 220 can typically be an acoustic-optic modulator or an electro-optic modulator.

[0074] Specifically, the femtosecond laser pulse signal emitted from the femtosecond seed source laser 300 is amplified by the preamplifier 210 and then broadened to the tens of picoseconds to nanoseconds by the chirped pulse broadening and compression device 100. The pulse is then output from the broadened output end and enters the cascaded multi-stage amplifier 230. After being fully amplified, the optical pulse is output from the amplification system 200 and then re-injected into the chirped pulse broadening and compression device 100 from the compression input end. The time-domain pulse width is compressed to the femtosecond level and finally output from the compression output end.

[0075] The amplification system 200 provided in this embodiment includes the chirped pulse broadening and compression device 100 in any of the above embodiments, and therefore has all the beneficial effects of the chirped pulse broadening and compression device 100 in any of the above embodiments, which will not be described in detail here.

[0076] In summary, this application proposes a chirped pulse stretching and compression device 100. Compared with the existing scheme that uses a single CVBG as both a stretcher and a compressor, this application overcomes the shortcomings of unadjustable dispersion and uncompensated additional dispersion in the amplification link. This allows the final output pulse width to reach the femtosecond level, and the pulse width can be adjusted according to the application requirements to flexibly adapt to different amplification systems 200, enabling the output optical pulse to achieve near-zero chirp and realize ultra-short pulse width.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A chirped pulse broadening and compression device, characterized in that, include: A first polarizing beam splitter has a first port, a second port, a third port and a fourth port. The first port and the third port are located on opposite sides of the first polarizing beam splitter, and the second port and the fourth port are located on opposite sides of the first polarizing beam splitter. The first port, the second port, the third port and the fourth port are not on the same side of the first polarizing beam splitter. A pulse stretching and compression device has a stretching port for receiving an optical pulse to be stretched and a compression port for receiving an optical pulse to be compressed, which are disposed opposite to each other, the stretching port being disposed on one side of the fourth port; A dispersion modulator, disposed on one side of the third port, is used to provide group delay dispersion for the light pulse emitted through the third port; The seed pulse enters the first polarization beam splitter through the first port and exits from the third port. After entering the dispersion modulator, it is reflected back along the original path, enters the first polarization beam splitter again through the third port, and then enters the pulse stretching compressor through the fourth port. After time-domain stretching in the pulse stretching compressor, it exits sequentially through the fourth port, the first polarization beam splitter, and the second port. The dispersion modulator includes: Dispersive element, wherein the dispersive element is one of a grating pair, a chirped mirror, a group of chirped mirrors, or a prism pair; A reflector is disposed on the side of the dispersive element opposite to the third port; It also includes an electrically controlled displacement stage. When the dispersive element is a grating pair or a prism pair, the dispersive element is mounted on the electrically controlled displacement stage. The electrically controlled displacement stage is used to adjust the distance between the two gratings in the grating pair or the distance between the two prisms in the prism pair.

2. The chirped pulse broadening and compression device according to claim 1, characterized in that, The dispersive element is a grating pair, in which the two gratings are parallel to each other.

3. The chirped pulse broadening and compression device according to claim 1, characterized in that, The reflector causes the incident light to pass through the grating pair or prism pair again and return to the third port along the original path.

4. The chirped pulse broadening and compression device according to any one of claims 1 to 3, characterized in that, A first waveplate is provided at the first port, a second waveplate is provided between the third port and the dispersion adjuster, and a third waveplate is provided between the fourth port and the widening port.

5. The chirped pulse broadening and compression device according to claim 4, characterized in that, The first waveplate is a half-wave plate, and the second and third waveplates are both quarter-wave plates.

6. The chirped pulse broadening and compression device according to claim 1, characterized in that, It also includes a second polarizing beam splitter, which has a fifth port, a sixth port and a seventh port. The sixth port and the seventh port are located on two opposite sides of the second polarizing beam splitter. The sixth port is correspondingly arranged with the compression port, and a fourth waveplate is arranged between the compression port and the sixth port. A fifth waveplate is arranged at the fifth port. The amplified beam enters from the compression input end, passes through the fifth waveplate and the second polarizing beam splitter, and exits perpendicular to the incident beam. It then enters the pulse broadening compressor from the sixth port for compression, passes through the fourth waveplate and the second polarizing beam splitter again, and exits from the seventh port.

7. The chirped pulse broadening and compression device according to claim 6, characterized in that, The fourth waveplate is a quarter waveplate, and the fifth waveplate is a half waveplate.

8. The chirped pulse broadening and compression device according to claim 1, characterized in that, The pulse broadening compressor is a chirped volume grating.

9. An amplification system, characterized in that, The device includes the chirped pulse broadening and compression apparatus according to any one of claims 1 to 8.

Images