Terahertz radiation generation system based on a combination of chirped beat and tilted wavefront techniques

Abstract

The utility model discloses a terahertz radiation generation system based on chirp beat frequency and tilt wave front technology combination, include: multichannel laser output device based on initial laser signal output first laser signal and second laser signal, the second laser signal of multichannel laser output device output produces chirp pulse after parallel grating, and the chirp pulse produces two outgoing pulses with relative time delay and forms an electromagnetic wave pulse of quasi-sine light intensity envelope modulation after the Fabry -Perot cavity, the electromagnetic wave pulse produces tilt wave front pulse through reflection grating, and the tilt wave front pulse incidence to terahertz radiation source produces multi -cycle terahertz pulse, the first laser signal of multichannel laser output device output enters first off -axis mirror after the cambered surface mirror, and the multi -cycle terahertz pulse of terahertz radiation source produces the beam combination and acts on electro-optic crystal to generate terahertz wave signal. Visible, the utility model can improve the energy conversion efficiency of laser to terahertz wave.

Description

Technical Field

[0001] This utility model relates to the field of optoelectronic technology, and in particular to a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology. Background Technology

[0002] Terahertz waves (THz) are electromagnetic waves with frequencies ranging from 0.1 THz to 10 THz (wavelengths of approximately 30 μm to 3 mm), representing a transitional frequency band between microwaves and infrared radiation. This band possesses both electrical and optical characteristics, serving as a crucial bridge between traditional electronics and microscopic spectroscopy, thus holding significant importance in spectral structure analysis. Compared to microwaves, terahertz waves offer higher frequency resolution; compared to infrared light, they have longer wavelengths and stronger penetrating power. These properties make terahertz waves an ideal tool for studying low-energy excitation processes, material spectral responses, and vibrational modes of biomolecules, attracting widespread attention in several cutting-edge fields in recent years.

[0003] Traditional terahertz wave generation methods, such as optical rectification using low-nonlinear crystals like ZnTe, typically produce terahertz waves with energy levels in the nJ range and limited tuning capabilities. In other words, traditional terahertz wave generation methods suffer from low energy conversion efficiency. Therefore, designing a terahertz radiation generation device to improve the energy conversion efficiency from laser to terahertz waves is essential. Utility Model Content

[0004] This invention provides a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology, which can improve the energy conversion efficiency from laser to terahertz wave.

[0005] To address the aforementioned technical problems, the first aspect of this utility model discloses a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology, the system comprising: A multi-channel laser output device, wherein the multi-channel laser output device is used to output a first laser signal and a second laser signal based on an initial laser signal, wherein the energy percentage of the first laser signal is less than the energy percentage of the second laser signal; The first laser processing branch includes a first off-axis parabolic mirror; The second laser processing branch includes a pair of parallel gratings, a Fabry-Perot cavity, a reflecting grating, and a terahertz radiation source. The second laser signal output from the multi-channel laser output device is processed by the pair of parallel gratings to generate a chirped pulse. The chirped pulse is then processed by the Fabry-Perot cavity to generate two outgoing pulses with relative time delays, which overlap to form a quasi-sinusoidal intensity envelope-modulated electromagnetic wave pulse. The electromagnetic wave pulse is processed by the reflecting grating to generate a tilted wavefront pulse. The tilted wavefront pulse is incident on the terahertz radiation source to generate a multi-period terahertz pulse. A terahertz wave generating device, wherein the terahertz wave generating device includes an electro-optic crystal; Wherein, the first laser signal output by the multi-channel laser output device enters the first off-axis parabolic mirror, and is combined with the multi-period terahertz pulse generated by the terahertz radiation source and acts on the electro-optic crystal to generate a terahertz wave signal.

[0006] As an optional implementation, in the first aspect of this invention, the multi-channel laser output device includes: Femtosecond lasers and beam splitters; The single-pulse femtosecond laser output by the femtosecond laser is split by the beam splitter to generate the first laser signal and the second laser signal.

[0007] As an optional implementation, in the first aspect of this utility model, the femtosecond laser is a Ti:sapphire laser with a center wavelength of 800 nm, energy in the millijoule range, and pulse width in the hundreds of femtosecond range, which outputs the single-pulse femtosecond laser.

[0008] As an optional implementation, in the first aspect of this invention, the parallel grating pair adjusts the position of each frequency component in the second laser signal in the time domain by introducing a frequency-related phase shift to generate the chirped pulse.

[0009] As an optional implementation, in the first aspect of this utility model, the second laser processing branch further includes: a first half-wave plate and a thin-film polarizer; The first half-wave plate and the thin-film polarizer are sequentially arranged after the Fabry-Perot cavity and before the reflective grating. After the electromagnetic wave pulse is polarized by the first half-wave plate, it enters the thin-film polarizer, which splits the electromagnetic wave pulse according to the polarization direction and outputs a continuous laser beam.

[0010] As an optional implementation, in the first aspect of this utility model, the second laser processing branch further includes: an optical chopper; The optical chopper is positioned after the thin-film polarizer and before the reflective grating, and the optical chopper is used to modulate the continuous laser beam output by the thin-film polarizer; Furthermore, the second laser processing branch also includes: a second half-wave plate; The second half-wave plate is disposed after the optical chopper and before the reflective grating, and is used to adjust the direction of the continuous laser beam to a horizontal direction.

[0011] As an optional implementation, in the first aspect of this utility model, the second laser processing branch further includes: a third half-wave plate and an imaging device; The third half-wave plate and the imaging device are sequentially arranged after the reflective grating and before the terahertz radiation source; the tilted wavefront pulse generated by the reflective grating passes through the third half-wave plate and the imaging device and is incident perpendicularly on the terahertz radiation source along the optical path.

[0012] As an optional implementation, in the first aspect of this utility model, the imaging device includes a first convex lens and a second convex lens, wherein the focal length of the first convex lens is f1 and the focal length of the second convex lens is f2. Wherein, the tilted wavefront pulse generated by the reflected grating and incident on the terahertz radiation source must satisfy the following: The distance from the reflective grating to the first convex lens is f1; the distance from the first convex lens to the second convex lens is f1+f2; and the distance from the second convex lens to the surface of the terahertz radiation source is f2.

[0013] As an optional implementation, in the first aspect of this utility model, the second laser processing branch further includes: a second off-axis parabolic mirror; The second off-axis parabolic mirror is disposed after the terahertz radiation source, and the second off-axis parabolic mirror is used to convert the divergent conical multi-period terahertz radiation output by the terahertz radiation source into parallel-emitting multi-period terahertz pulses through off-axis reflection.

[0014] As an optional implementation, in the first aspect of this utility model, the first laser processing branch further includes: an optical delayer; The optical delay unit is positioned in front of the first off-axis parabolic mirror, and the optical delay unit is used to adjust the time delay of the first laser signal; Furthermore, the first laser processing branch also includes: a filter; The filter is disposed between the optical delay unit and the first off-axis parabolic mirror, and the filter is used to reduce the light intensity of the first laser signal.

[0015] Implementing this utility model has the following beneficial effects: In this invention, a multi-channel laser output device outputs a first laser signal and a second laser signal based on an initial laser signal. The second laser signal output by the multi-channel laser output device generates a chirped pulse after passing through a parallel grating pair. The chirped pulse, after passing through a Fabry-Perot cavity, generates two outgoing pulses with relative time delays, which overlap to form a quasi-sinusoidal intensity envelope-modulated electromagnetic wave pulse. The electromagnetic wave pulse passes through a reflective grating to generate a tilted wavefront pulse. The tilted wavefront pulse is incident on a terahertz radiation source to generate a multi-period terahertz pulse. The first laser signal output by the multi-channel laser output device enters a first off-axis parabolic mirror and is combined with the multi-period terahertz pulse generated by the terahertz radiation source and acts on an electro-optic crystal to generate a terahertz wave signal. It is evident that this invention can combine chirped beat frequency technology and tilted wavefront technology in a terahertz wave signal generation system, significantly improving the conversion efficiency from laser to terahertz wave and thus increasing the generated terahertz energy. Furthermore, multi-cycle pulses can be controlled by adjusting the pulse width of the chirped pulse and the time delay between two pulses, improving the ease and flexibility of multi-cycle pulse control, and the structure is simple. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology disclosed in an embodiment of this utility model; Figure 2 This is a schematic diagram of another terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology disclosed in this utility model embodiment. Detailed Implementation

[0018] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] It should be noted that, unless otherwise explicitly specified and limited, the term "electrical connection" in the specification, claims, and accompanying drawings of this utility model should be interpreted broadly. For example, it can refer to a fixed electrical connection, a detachable electrical connection, or an integral electrical connection; it can refer to a mechanical electrical connection or a mutually communicating connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two components or the interaction between two components. Furthermore, the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish different objects, not to describe a specific order. The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] This invention discloses a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront techniques. This system combines chirped beat frequency and tilted wavefront techniques for terahertz wave signal generation, significantly improving the laser-to-terahertz wave conversion efficiency and thus increasing the generated terahertz energy. Furthermore, multi-cycle pulses can be controlled by adjusting the pulse width of the chirped pulse and the time delay between two pulses, improving the ease and flexibility of multi-cycle pulse control, while maintaining a simple structure. The following descriptions are based on... Figure 1-2 The structure of a terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront techniques is described in detail.

[0021] like Figure 1-2 As shown, the terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront techniques may include: A multi-channel laser output device 101 is used to output a first laser signal and a second laser signal based on an initial laser signal, wherein the energy percentage of the first laser signal is less than the energy percentage of the second laser signal. The first laser processing branch 102 includes a first off-axis parabolic mirror 1021; The second laser processing branch 103 includes a parallel grating pair 1031, a Fabry-Perot cavity 1032, a reflection grating 1033, and a terahertz radiation source 1034. The second laser signal output by the multi-channel laser output device 101 generates a chirped pulse after passing through the parallel grating pair 1031. The chirped pulse then passes through the Fabry-Perot cavity 1032 to generate two outgoing pulses with relative time delays, which overlap to form a quasi-sinusoidal intensity envelope modulated electromagnetic wave pulse. The electromagnetic wave pulse passes through the reflection grating 1033 to generate a tilted wavefront pulse. The tilted wavefront pulse is incident on the terahertz radiation source 1034 to generate a multi-period terahertz pulse. Terahertz wave generating device 104, which includes an electro-optic crystal 1041; In this process, the first laser signal output from the multi-channel laser output device 101 enters the first off-axis parabolic mirror 1021, and is then combined with multi-period terahertz pulses generated by the terahertz radiation source 1034, acting on the electro-optic crystal 1041 to generate a terahertz wave signal. Optionally, the terahertz wave signal can be detected by a terahertz detection device. Figure 1-2 Not shown in the image.

[0022] Optionally, the terahertz radiation source 1034 can be a lithium niobate crystal. More preferably, the lithium niobate crystal is doped with 5-6.2 mol% magnesium oxide, and the lithium niobate crystal has a triangular prism structure with a base angle of approximately 63 degrees and a apex angle of approximately 54 degrees. The polarization direction of the incident light is parallel to the crystal axis of the lithium niobate crystal, and the angle between the incident and exit surfaces is approximately 63 degrees. This is done to ensure that the generated terahertz radiation direction is perpendicular to the exit surface, thereby reducing energy loss due to reflection and improving conversion efficiency.

[0023] As can be seen, the present invention can combine chirped beat frequency technology and tilted wavefront technology in a terahertz wave signal generation system, which significantly improves the conversion efficiency from laser to terahertz wave and is beneficial to increasing the generated terahertz energy. In addition, multi-cycle pulses can be controlled by adjusting the pulse width of the chirped pulse and the time delay between the two pulses, which improves the convenience and flexibility of multi-cycle pulse control and the structure is simple.

[0024] In an optional embodiment, please refer to Figure 2 The aforementioned multi-channel laser output device 101 may include: Femtosecond laser 1011 and beam splitter 1012; The single-pulse femtosecond laser output by the femtosecond laser 1011 is split by the beam splitter 1012 to generate a first laser signal and a second laser signal.

[0025] Optionally, the beam splitter 1012 is a non-polarizing beam splitter. After the single-pulse femtosecond laser is split by the non-polarizing beam splitter, the incident beam is incident on the coated surface. Most of the incident light is reflected by the coated surface to form a second laser signal, while a small portion of the transmitted light forms a first laser signal for subsequent electro-optic sampling. The splitting ratio of the beam splitter 1012 can be adjusted or set according to actual needs.

[0026] Alternatively, the femtosecond laser 1011 can be a Ti:sapphire laser with a center wavelength of 800 nm, energy in the millijoule range, and pulse width in the hundreds of femtosecond range to output a single-pulse femtosecond laser.

[0027] As can be seen, this optional embodiment can split a single-pulse femtosecond laser into two laser beams using the beam splitter 1012, improving the convenience and flexibility of laser beam splitting, and is simple in structure and easy to implement. Furthermore, outputting a single-pulse femtosecond laser from a Ti:sapphire laser with a center wavelength of 800 nm, energy in the millijoule range, and pulse width in the hundreds of femtosecond range helps ensure the stable output of high-intensity terahertz wave signals.

[0028] In yet another alternative embodiment, the parallel grating pair 1031 generates chirped pulses by introducing a frequency-dependent phase shift to adjust the position of each frequency component in the time domain of the second laser signal.

[0029] As can be seen, this optional embodiment can generate chirped pulses with a larger pulse width based on the parallel grating 1031. This not only reduces the peak power of the second laser signal and avoids or reduces damage to the terahertz radiation source 1034, thus improving the upper limit of energy injection, but also broadens the spectral coverage of the terahertz wave, thereby adapting to the requirements of wide-band applications. It can also compensate for group velocity mismatch, extend the effective action length, improve terahertz conversion efficiency, and regulate the time-domain characteristics of the terahertz pulse to generate multi-period, stable terahertz signals. Furthermore, it is conducive to adapting to high-power terahertz generation systems and is compatible with subsequent optical control links.

[0030] In yet another optional embodiment, the second laser processing branch 103 further includes: a first half-wave plate 1035 and a thin-film polarizer 1036; The first half-wave plate (HWP) 1035 and the thin film polarizer (TFP) 1036 are sequentially arranged after the Fabry-Perot cavity 1032 and before the reflective grating 1033. After the electromagnetic wave pulse is polarized by the first half-wave plate 1035, it enters the thin film polarizer 1036. The thin film polarizer 1036 splits the electromagnetic wave pulse according to the polarization direction and outputs a continuous laser beam.

[0031] In this optional embodiment, the first half-wave plate (HWP) and the thin-film polarizer (TFP) can constitute a light intensity regulator. The thin-film polarizer (TFP) has different reflection and transmission characteristics for light with different polarization directions. By rotating the half-wave plate to change the polarization direction of the linearly polarized light incident on the thin-film polarizer, the splitting ratio can be continuously adjusted, thereby achieving precise control of the energy of the second laser signal light during the terahertz wave generation process, and thus optimizing the terahertz wave generation efficiency.

[0032] In yet another optional embodiment, the second laser processing branch 103 further includes an optical chopper 1037; An optical chopper 1037 is positioned after the thin-film polarizer 1036 and before the reflective grating 1033. The optical chopper 1037 is used to modulate the continuous laser beam output by the thin-film polarizer 1036. In this optional embodiment, the polarization-modulated light after passing through the first half-wave plate 1035 and the thin-film polarizer 1036 is continuously and stably linearly polarized light. The optical chopper 1037 can modulate it into a fixed-frequency alternating light signal (such as a square wave or sine wave signal) by periodically blocking it, while the background stray light (a small amount of co-polarized light and ambient light mixed in after non-target polarized light is scattered) remains a DC signal. In addition, the optical chopper 1037 causes the second laser signal to irradiate the crystal at a fixed frequency, and the first laser processing branch 102 synchronously collects the terahertz wave signal to ensure that the terahertz wave excited by the second laser processing branch 103 can be accurately captured each time, avoiding or reducing signal misalignment in time.

[0033] In yet another optional embodiment, the second laser processing branch 103 further includes a second half-wave plate 1038; The second half-wave plate 1038 is positioned after the optical chopper 1037 and before the reflective grating 1033. The second half-wave plate 1038 is used to adjust the direction of the continuous laser beam to a horizontal direction.

[0034] As can be seen, in this optional embodiment, the beam direction is adjusted to a horizontal direction by the second half-wave plate 1038 before being incident on the terahertz radiation source 1034, which is beneficial to improving the energy and stability of the multi-cycle terahertz pulses radiated by the terahertz radiation source 1034.

[0035] Optionally, the electromagnetic wave pulse generates a tilted wavefront pulse through the reflection grating 1033. The tilted wavefront at a specific angle can be generated by finely adjusting the angle of the incident electromagnetic wave pulse relative to the reflection grating 1033 to meet the phase matching condition, thereby ensuring that the incident light incident on the terahertz radiation source 1034 is non-collinearly phase matched with the terahertz wave.

[0036] In yet another optional embodiment, the second laser processing branch 103 further includes a third half-wave plate 1039 and an imaging device 10310. The third half-wave plate 1039 and the imaging device 10310 are sequentially arranged after the reflection grating 1033 and before the terahertz radiation source 1034; the tilted wavefront pulse generated by the reflection grating 1033 passes through the third half-wave plate 1039 and the imaging device 10310 and is then perpendicularly incident on the terahertz radiation source 1034 along the optical path.

[0037] In this optional embodiment, the third half-wave plate 1039 can not only correct the polarization shift and ensure that the pulse incident on the terahertz radiation source 1034 is "polarized matched" with the terahertz radiation source 1034, but also ensure that the tilted wavefront pulse is incident perpendicularly on the terahertz radiation source 1034 along the optical path. This not only ensures the quality of the terahertz signal, but also maximizes the nonlinear effect, thereby improving the energy conversion efficiency.

[0038] In yet another optional embodiment, the imaging device 10310 includes a first convex lens 103101 and a second convex lens 103102, the first convex lens 103101 having a focal length of f1 and the second convex lens 103102 having a focal length of f2. Specifically, the tilted wavefront pulse generated by the reflective grating 1033 and incident on the terahertz radiation source 1034 must satisfy the following: The distance from the reflective grating 1033 to the first convex lens 103101 is f1; the distance from the first convex lens 103101 to the second convex lens 103102 is f1+f2; and the distance from the second convex lens 103102 to the surface of the terahertz radiation source 1034 is f2.

[0039] In this optional embodiment, the tilted wavefront pulse generated by the reflective grating 1033 is ensured to be perpendicularly incident on the terahertz radiation source 1034 by adjusting the distance between the reflective grating 1033, the first convex lens 103101, the second convex lens 103102 and the surface of the terahertz radiation source 1034. The adjustment method is simple, flexible and easy to implement.

[0040] In yet another optional embodiment, the second laser processing branch 103 further includes: a second off-axis parabolic mirror 10311; The second off-axis parabolic mirror 10311 is positioned after the terahertz radiation source 1034, and is used to convert the divergent, cone-shaped multi-period terahertz radiation output from the terahertz radiation source into parallel-emitting multi-period terahertz pulses through off-axis reflection.

[0041] This optional embodiment can reduce energy diffusion during transmission through the second off-axis parabolic mirror 10311, thereby reducing energy waste and improving energy conversion efficiency.

[0042] In yet another optional embodiment, the first laser processing branch 102 further includes an optical delay unit 1022; The optical delay unit 1022 is positioned before the first off-axis parabolic mirror 1021, and the optical delay unit 1022 is used to adjust the time delay of the first laser signal; In this optional embodiment, when the first laser signal passes through the optical delay unit 1022, the time delay of the first laser signal relative to the terahertz radiation is changed by finely adjusting the optical path. Typically, a time interval of 50 fs is used to ensure that the first laser signal and the multi-cycle terahertz pulse reach the first off-axis parabolic mirror 1021 synchronously for beam combining, which helps to ensure effective beam combining / superposition of the first laser signal and the multi-cycle terahertz pulse.

[0043] In yet another alternative embodiment, such as Figure 2 As shown, the first laser processing branch 102 also includes: a filter 1023; The filter 1023 is disposed between the optical delay unit 1022 and the first off-axis parabolic mirror 1021, and the filter 1023 is used to reduce the light intensity of the first laser signal.

[0044] In this optional embodiment, the first laser signal is time-delayed by the optical delayer 1023 and then passes through the filter 1023. The filter 1023 reduces the light intensity of the first laser signal, thereby reducing the occurrence of damage to the optical element due to the light intensity exceeding the damage threshold of the optical element, which is beneficial to improving the safety and stability of the system.

[0045] In yet another alternative embodiment, such as Figure 2 As shown, the first laser processing branch 102 also includes a lens 1024; Lens 1024 is disposed between filter 1023 and first off-axis parabolic mirror 1021, and lens 1024 is used to incident the first laser signal parallel to the first off-axis parabolic mirror 1021.

[0046] This optional embodiment can use lens 1024 to incident the first laser signal parallel to the first off-axis parabolic mirror 1021 and combine it with multi-period terahertz pulses, which is beneficial to improving the energy conversion efficiency.

[0047] The foregoing has provided a detailed description of a terahertz radiation generation device based on a parallel grating pair and a Fabry-Perot cavity, as disclosed in the embodiments of this utility model. Specific embodiments have been used to illustrate the principles and implementation methods of this utility model. However, the above preferred embodiments are not intended to limit this utility model. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this utility model. Furthermore, for those skilled in the art, based on the ideas of this utility model, changes may be made in the specific implementation methods and application scope without departing from the spirit and scope of this utility model. Therefore, the protection scope of this utility model is determined by the scope defined in the claims.

Claims

1. A terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront techniques, characterized in that, The system includes: A multi-channel laser output device (101) is used to output a first laser signal and a second laser signal based on an initial laser signal, wherein the energy percentage of the first laser signal is less than the energy percentage of the second laser signal. The first laser processing branch (102) includes a first off-axis parabolic mirror (1021). The second laser processing branch (103) includes a parallel grating pair (1031), a Fabry-Perot cavity (1032), a reflection grating (1033), and a terahertz radiation source (1034). The second laser signal output by the multi-channel laser output device (101) generates a chirped pulse after passing through the parallel grating pair (1031). The chirped pulse generates two outgoing pulses with relative time delays after passing through the Fabry-Perot cavity (1032), which overlap to form a quasi-sinusoidal intensity envelope modulated electromagnetic wave pulse. The electromagnetic wave pulse generates a tilted wavefront pulse after passing through the reflection grating (1033). The tilted wavefront pulse is incident on the terahertz radiation source (1034) to generate a multi-period terahertz pulse. Terahertz wave generating device (104), the terahertz wave generating device (104) includes an electro-optic crystal (1041). The first laser signal output by the multi-channel laser output device (101) enters the first off-axis parabolic mirror (1021), and is then combined with the multi-period terahertz pulse generated by the terahertz radiation source (1034) and applied to the electro-optic crystal (1041) to generate a terahertz wave signal.

2. The terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront technology according to claim 1, characterized in that, The multi-channel laser output device (101) includes: Femtosecond laser (1011) and beam splitter (1012); The single-pulse femtosecond laser output by the femtosecond laser (1011) is split by the beam splitter (1012) to generate the first laser signal and the second laser signal.

3. The terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront technology according to claim 2, characterized in that, The femtosecond laser (1011) uses a Ti:sapphire laser with a center wavelength of 800 nm, energy in the millijoule range, and pulse width in the hundreds of femtosecond range to output the single-pulse femtosecond laser.

4. The terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology according to any one of claims 1-3, characterized in that, The parallel grating pair (1031) generates the chirped pulse by introducing a frequency-related phase shift to adjust the position of each frequency component in the second laser signal in the time domain.

5. The terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology according to any one of claims 1-3, characterized in that, The second laser processing branch (103) further includes: a first half-wave plate (1035) and a thin-film polarizer (1036). The first half-wave plate (1035) and the thin-film polarizer (1036) are sequentially arranged after the Fabry-Perot cavity (1032) and before the reflective grating (1033). The electromagnetic wave pulse enters the thin-film polarizer (1036) after the polarization direction is adjusted by the first half-wave plate (1035). The thin-film polarizer (1036) splits the electromagnetic wave pulse according to the polarization direction and outputs a continuous laser beam.

6. The terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront technology according to claim 5, characterized in that, The second laser processing branch (103) also includes: an optical chopper (1037); The optical chopper (1037) is disposed after the thin-film polarizer (1036) and before the reflective grating (1033), and the optical chopper (1037) is used to modulate the continuous laser beam output by the thin-film polarizer (1036). In addition, the second laser processing branch (103) further includes: a second half-wave plate (1038). The second half-wave plate (1038) is disposed after the optical chopper (1037) and before the reflective grating (1033), and the second half-wave plate (1038) is used to adjust the direction of the continuous laser beam to the horizontal direction.

7. The terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront technology according to claim 6, characterized in that, The second laser processing branch (103) also includes: a third half-wave plate (1039) and an imaging device (10310). The third half-wave plate (1039) and the imaging device (10310) are sequentially arranged after the reflection grating (1033) and before the terahertz radiation source (1034); the tilted wavefront pulse generated by the reflection grating (1033) passes through the third half-wave plate (1039) and the imaging device (10310) and is then perpendicularly incident on the terahertz radiation source (1034) along the optical path.

8. The terahertz radiation generation system based on the combination of chirped beat frequency and tilted wavefront technology according to claim 7, characterized in that, The imaging device (10310) includes a first convex lens (103101) and a second convex lens (103102), wherein the focal length of the first convex lens (103101) is f1 and the focal length of the second convex lens (103102) is f2. Wherein, the tilted wavefront pulse generated by the reflective grating (1033) and incident on the terahertz radiation source (1034) must satisfy the following: The distance from the reflective grating (1033) to the first convex lens (103101) is f1; the distance from the first convex lens (103101) to the second convex lens (103102) is f1+f2; and the distance from the second convex lens (103102) to the surface of the terahertz radiation source (1034) is f2.

9. The terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology according to any one of claims 1-3, characterized in that, The second laser processing branch (103) also includes: a second off-axis parabolic mirror (10311); The second off-axis parabolic mirror (10311) is disposed after the terahertz radiation source (1034), and the second off-axis parabolic mirror (10311) is used to convert the divergent conical multi-period terahertz radiation output by the terahertz radiation source into parallel-emitting multi-period terahertz pulses through off-axis reflection.

10. The terahertz radiation generation system based on a combination of chirped beat frequency and tilted wavefront technology according to any one of claims 1-3, characterized in that, The first laser processing branch (102) further includes: an optical delay unit (1022); The optical delay unit (1022) is positioned in front of the first off-axis parabolic mirror (1021), and the optical delay unit (1022) is used to adjust the time delay of the first laser signal; In addition, the first laser processing branch (102) further includes: a filter (1023); The filter (1023) is disposed between the optical delay unit (1022) and the first off-axis parabolic mirror (1021), and the filter (1023) is used to reduce the light intensity of the first laser signal.

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