Laser M based on beam Gaussian transmission transformation 2 Factor measurement device and method

Abstract

The application relates to a laser M 2 The application relates to a factor measuring device and method, wherein the optical conversion system is provided with a focusing optical element, the first light spot detection system is provided with a first cross-section detector, a first camera and a leading-out mirror, the second light spot detection system is provided with a second cross-section detector and a second camera, the third light spot detection system is provided with a third cross-section detector and a third camera, the original Gaussian light beam is converted into a measuring main light path through the focusing optical element and the leading-out mirror, the first cross-section detector, the second cross-section detector and the third cross-section detector are all provided with fluorescent elements which can enter and exit the measuring main light path, and the fluorescent elements form fluorescent light paths after entering the measuring main light path and are shot into corresponding cameras, a length adjusting pipe is arranged on a vacuum pipe between the second light spot detection system and the third light spot detection system, and the third cross-section detector is located at the beam waist of the measuring main light path. 2 The application fills up the blank of the factor detection technology in the field of free electron lasers.

Description

Technical Field

[0001] This invention relates to the field of free-electron laser measurement, specifically to a laser M-type laser measurement method based on Gaussian beam propagation transformation. 2 Factor measurement device and method. Background Technology

[0002] Free-electron lasers have numerous applications in the interaction of light with atoms, molecules, and condensed matter, particularly in ion imaging. The unique properties of free-electron lasers make them highly promising for imaging the ionization of water ions. The M-axis of the laser... 2 The laser factor is an important parameter of lasers and a core parameter in imaging; the output light's M... 2 Factors directly affect parameters such as the emissivity and cross-sectional area of ​​emitted light, which are essential parameters for the design and operation of imaging experiments.

[0003] But M 2 Factor measurement requires measuring the beam waist, but the beam waist of a free electron laser is inside a undulator. The space inside the undulator is too small to install detection equipment. Furthermore, the beam and electron beam propagate together at the undulator, and the presence of the electron beam will affect the detection of the cross-sectional area. In addition, too much beam loss and too strong radiation will also affect the normal use of the detector.

[0004] In the infrared or visible light bands, lenses are typically used to transform the laser beam, and the size and position of the transformed laser beam waist, as well as the spot size at the lens focal length, are measured. The Gaussian distribution parameters of the original laser are then derived using the optical transmission transformation matrix of the paraxial lens. However, free-electron lasers have shorter wavelengths, and it is difficult to find transmissive materials in the short-wavelength band. Therefore, lenses cannot be used to transform the beam of free-electron lasers. The M in the visible light band... 2 The design concept and principle of the factor measurement device are no longer applicable, and a new device structure needs to be designed. Summary of the Invention

[0005] The purpose of this invention is to provide a laser M based on Gaussian beam propagation transformation. 2 The device and method for measuring the factor derives a conversion formula applicable to free-electron lasers based on the transformation theory of grazing incidence using a focusing optical element (super-toroidal mirror), filling a gap in the field of free-electron laser M... 2 The gap in factor detection technology.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A laser M based on beam Gaussian transmission transformation 2The factor measurement device includes an optical conversion system, a first spot detection system, a second spot detection system, and a third spot detection system connected in sequence through a vacuum pipe. The optical conversion system is equipped with a movable focusing optical element. The first spot detection system is equipped with a first cross-section detector, a first camera, and an extraction mirror. The second spot detection system is equipped with a second cross-section detector and a second camera. The third spot detection system is equipped with a third cross-section detector and a third camera. The original Gaussian beam is converted by the focusing optical element and the extraction mirror to form the main measurement optical path. The first, second, and third cross-section detectors are all equipped with fluorescent elements that can enter and exit the main measurement optical path. After entering the main measurement optical path, the fluorescent elements form a fluorescent light path that is directed into the corresponding camera. A length adjustment tube is provided on the vacuum pipe between the second and third spot detection systems, and the third cross-section detector is located at the waist of the main measurement optical path.

[0008] The vacuum cavity of the optical conversion system is equipped with a vacuum linear displacement stage, and the vacuum linear displacement stage is equipped with a focusing optical element.

[0009] The outer side of the vacuum cavity of the optical conversion system is equipped with an observation window and a vacuum gauge.

[0010] The vacuum cavity of the first spot detection system is provided with a first window, a first vacuum gauge and a first angle valve on the outside, wherein the first window is aligned with the first camera and the first angle valve is connected to the first vacuum generating component.

[0011] The vacuum cavity of the second spot detection system is provided with a second window and a second vacuum gauge on the outside, wherein the second window is aligned with the second camera.

[0012] The vacuum cavity of the third spot detection system is provided with a third window, a third vacuum gauge and a second angle valve on the outside. The third window is aligned with the third camera and the second angle valve is connected to the second vacuum generating component.

[0013] The first cross-section detector, the second cross-section detector, and the third cross-section detector have the same structure, each including a fluorescent element, a mounting base, an adjustment base, and an adjustment base driving mechanism. The fluorescent element is disposed on the mounting base, the upper end of the mounting base is fixedly connected to the adjustment base, and the adjustment base is driven to move by the adjustment driving mechanism.

[0014] The focusing optical element is a toroidal mirror.

[0015] A laser M based on the aforementioned Gaussian beam propagation transformation 2 The measurement method of the factor measurement device involves the fluorescent element of the first cross-section detector entering the main measurement optical path first, and the first camera obtaining the radius size W of the first measurement spot. 21Then, the fluorescent element of the first cross-section detector exits, and the fluorescent element of the second cross-section detector enters the main measurement optical path, allowing the second camera to obtain the second measurement spot radius size W. 22 The distance between the first and second cross-section detectors is ΔZ. The divergence angle θ2 of the main optical path is obtained according to the following formula:

[0016]

[0017] Then, the divergence angle θ1 of the original Gaussian beam is obtained according to the following formula (2):

[0018]

[0019] Then the fluorescent element of the second cross-section detector exits, and the fluorescent element of the third cross-section detector enters the main optical path for measurement. The beam waist distance Z and the corresponding spot radius size W2(Z) of multiple points are obtained by adjusting the length of the length adjustment tube. Substituting these values ​​into the following formula (3) determines multiple sets of Z2 and W2. 02 The values ​​were calculated using software fitting to obtain the final waist position Z2 and dimension W. 02 :

[0020]

[0021] In equation (3) above, λ is the laser wavelength;

[0022] Then, the original beam waist position Z1 and size W are obtained according to the following equations (4) and (5). 01 :

[0023]

[0024]

[0025] In equation (5) above, f is the focal length of the focusing optical element 102;

[0026] Then, the M of the original Gaussian beam is obtained according to the following formula (6). 2 factor:

[0027]

[0028] Before measurement, the optical conversion system, the first spot detection system, the second spot detection system, the third spot detection system, and each vacuum pipe are evacuated to a set vacuum level. After the vacuum level is reached, the focusing optical element in the optical conversion system moves into the incident original Gaussian beam. The original Gaussian beam is converted by the focusing optical element and the lead-out mirror to form the main optical path for measurement.

[0029] The advantages and positive effects of this invention are as follows:

[0030] 1. This invention derives a conversion formula applicable to free-electron lasers using the transformation theory of grazing incidence of a focusing optical element (super-toroidal mirror), filling a gap in the field of free-electron lasers. 2 The gap in factor detection technology.

[0031] 2. The present invention includes a spot detection system, and the cross-sectional detector fluorescent element in each spot detection system can enter and exit the main optical path as needed to obtain the spot radius size, which is simple and convenient to control.

[0032] 3. The last set of spot detection systems in this invention can be adjusted in position by length adjustment tube, thereby driving the third cross-section detector to obtain multiple points near the waist of the converted Gaussian beam. Then, the precise size and accurate position of the waist of the converted Gaussian beam are determined by software fitting calculation, ensuring measurement accuracy.

[0033] 4. This invention can obtain the distance Z1 from the source point of the original Gaussian beam to the super-toroidal mirror and the beam waist radius W. 01 M 2 By analyzing multiple parameters such as the factor, a comprehensive understanding of the original beam information can be obtained, facilitating subsequent design reference and adjustments. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the present invention.

[0035] Figure 2 for Figure 1 A schematic diagram of the cross-section detector structure in the image.

[0036] Figure 3 for Figure 2 Schematic diagram of the drive mechanism of the mid-section detector.

[0037] Figure 4 This is a schematic diagram of the original Gaussian beam.

[0038] Wherein, 1 is an optical conversion system, 101 is a vacuum linear displacement stage, 102 is a focusing optical element, 103 is an observation window, 104 is a vacuum gauge, 2 is a vacuum inlet pipe, 201 is a connecting flange, 3 is a first spot detection system, 301 is an extraction mirror, 302 is a first angle adjustment frame, 303 is a first cross-section detector, 304 is a first vacuum gauge, 305 is a first angle valve, 306 is a first vacuum generating assembly, 307 is a first window, 308 is a first camera, 4 is a first vacuum pipe, 401 is a first flange, 5 is a second spot detection system, 501 is a second window, and 502 is... The second angle adjustment frame, 503 is the second cross-section detector, 504 is the second vacuum gauge, 505 is the second camera, 6 is the second vacuum pipe, 601 is the vacuum connection pipe, 602 is the length adjustment pipe, 603 is the second flange, 7 is the third spot detection system, 701 is the second angle valve, 702 is the third angle adjustment frame, 703 is the third cross-section detector, 704 is the third vacuum gauge, 705 is the third window, 706 is the third camera, 707 is the second vacuum generating assembly, 8 is the mechanical pump, 9 is the molecular pump, 10 is the mounting base, 11 is the adjustment base, 12 is the fluorescent element, 13 is the motor, and 14 is the lead screw. Detailed Implementation

[0039] The invention will now be described in further detail with reference to the accompanying drawings.

[0040] like Figures 1-4 As shown, the present invention includes an optical conversion system 1, a first spot detection system 3, a second spot detection system 5, and a third spot detection system 7 connected sequentially through a vacuum pipe. The first spot detection system 3 is equipped with a first cross-section detector 303, a first camera 308, and an extraction mirror 301. The second spot detection system 5 is equipped with a second cross-section detector 503 and a second camera 505. The third spot detection system 7 is equipped with a third cross-section detector 703 and a third camera 706. The original Gaussian beam is converted by the optical conversion system 1 and the extraction mirror 301 to form a parallel measurement main optical path (converted Gaussian beam), as shown below. Figure 2 As shown, the first cross-section detector 303, the second cross-section detector 503, and the third cross-section detector 703 are all equipped with fluorescent elements 12 that can enter and exit the main measurement optical path. After the fluorescent element 12 enters the main measurement optical path, it forms a fluorescent light path that is directed into the corresponding camera to obtain the measurement spot size. A length adjustment tube 602 is provided on the vacuum pipe between the second spot detection system 5 and the third spot detection system 7, and the third cross-section detector 703 is located at the waist of the main measurement optical path (i.e., the converted Gaussian beam). In this embodiment, the fluorescent element 12 is a fluorescent target. The principle is that after ultraviolet light irradiates the fluorescent element 12, a fluorescent spot will be formed on the fluorescent element 12. The size of this spot is the size that needs to be measured by the corresponding camera. The length adjustment tube 602 is a corrugated tube.

[0041] like Figure 1 As shown, the vacuum cavity of the optical conversion system 1 is provided with a vacuum linear displacement stage 101, and a focusing optical element 102 is provided on the vacuum linear displacement stage 101. The focusing optical element 102 is moved by the vacuum linear displacement stage 101 and the original Gaussian beam is focused and transformed and introduced into the first spot detection system 3. In this embodiment, the vacuum linear displacement stage 101 can be driven by a lead screw and nut structure, wherein the lead screw is driven to rotate by a motor, the nut is fitted on the lead screw, the displacement seat is fixedly connected to the nut, and the focusing optical element 102 is installed on the displacement seat. In addition, in this embodiment, the focusing optical element 102 is a toroidal mirror.

[0042] like Figure 1 As shown, the outer side of the vacuum cavity of the optical conversion system 1 is provided with an observation window 103 and a detection vacuum gauge 104 for detecting the vacuum level inside the cavity. The detection vacuum gauge 104 is a technology known in the art and is a commercially available product.

[0043] like Figure 1 As shown, the optical conversion system 1 is connected to the first spot detection system 3 through the vacuum pipe 2. Both ends of the vacuum pipe 2 are provided with connecting flanges 201 for sealing connection with the corresponding system.

[0044] like Figure 1 As shown, the vacuum chamber of the first spot detection system 3 has a first window 307 on one side aligned with the first camera 308, and a first angle valve 305 on the other side connected to the first vacuum generating assembly 306. The first vacuum generating assembly 306 is used to achieve a vacuum. In this embodiment, it includes a mechanical pump 8 and a molecular pump 9. The vacuum generating assembly is a technology known in the art. Additionally, as... Figure 1 As shown, a first vacuum gauge 304 for detecting the vacuum level inside the vacuum chamber is provided on the outside of the vacuum chamber of the first spot detection system 3. The first vacuum generating assembly 306 and the subsequent second vacuum generating assembly 707 are used to evacuate each vacuum chamber and pipe to ensure laser transmission.

[0045] like Figure 1 As shown, the first spot detection system 3 is connected to the second spot detection system 5 through the first vacuum pipe 4. Both ends of the first vacuum pipe 4 are provided with first flanges 401, which are respectively sealed to the corresponding system.

[0046] like Figure 1 As shown, the vacuum cavity of the second spot detection system 5 is provided with a second window 501 and a second vacuum gauge 504 on the outside, wherein the second window 501 is aligned with the second camera 505, and the second vacuum gauge 504 is used to detect the vacuum level inside the second spot detection system 5.

[0047] like Figure 1 As shown, the second spot detection system 5 is connected to the third spot detection system 7 via a second vacuum pipe 6. The second vacuum pipe 6 includes a vacuum connecting pipe 601 with a non-adjustable length and the length adjusting pipe 602. The length adjusting pipe 602 can change the position of the third spot detection system 7, thereby enabling the third section detector 703, located near the waist of the converted Gaussian beam, to obtain multiple waist points. Then, the precise size and accurate position of the waist of the converted Gaussian beam are determined by software fitting calculation. Figure 1 As shown, both the vacuum connection pipe 601 and the length adjustment pipe 602 are sealed to the corresponding system through the second flange 603.

[0048] like Figure 1 As shown, the vacuum chamber of the third spot detection system 7 is provided with a third window 705, a third vacuum gauge 704 and a second angle valve 701 on the outside. The third window 705 is aligned with the third camera 706. The third vacuum gauge 704 detects the vacuum level inside the cavity of the third spot detection system 7. The second angle valve 701 is connected to the second vacuum generating component 707 to realize the vacuum generation in the system. The structure of the second vacuum generating component 707 is the same as that of the first vacuum generating component 306.

[0049] like Figures 2-3 As shown, in this embodiment, the first cross-section detector 303, the second cross-section detector 503, and the third cross-section detector 703 have the same structure, each including a fluorescent element 12, a mounting base 10, an adjusting base 11, and an adjusting base driving mechanism. The fluorescent element 12 is disposed on the mounting base 10, the upper end of the mounting base 10 is fixedly connected to the adjusting base 11, and the adjusting base 11 is driven to move by the adjusting driving mechanism. In this embodiment, the adjusting driving mechanism includes a motor 13, a lead screw 14, and a lead screw nut. The lead screw 14 is driven to rotate by the motor 13, the lead screw nut is fitted onto the lead screw 14, and the adjusting base 11 is mounted on the lead screw nut and moved by the lead screw nut. Figure 1 As shown, the first spot detection system 3 is equipped with a first angle adjustment frame 302, the second spot detection system 5 is equipped with a second angle adjustment frame 502, and the third spot detection system is equipped with a third angle adjustment frame 702, as... Figures 2-3 As shown, the adjustment seat 11 and the adjustment seat drive mechanism are respectively mounted on the corresponding angle adjustment frame. The angle adjustment frame can adjust the angle of the fluorescent element 12 according to actual needs to ensure that each fluorescent light path is aligned with its respective camera, such as... Figure 1As shown, in this embodiment, the first fluorescent vertical light path branched off from the first cross-section detector 303 enters the first camera 308, the second fluorescent vertical light path branched off from the second cross-section detector 503 enters the second camera 505, and the third cross-section detector 702 directly emits the third fluorescent light path into the third camera 706. The fluorescent elements 12 of the first two cross-section detectors are at a 45° angle to the main measurement light path, and the camera field of view is perpendicular to the light path, ensuring that the spot size within the camera field of view is not distorted. The system obtains the measurement spot size of the first two cross-section detectors through a software fitting algorithm, while the last cross-section detector directly enters the main measurement light path. The position is adjusted by the length adjustment tube 602 to obtain the distance of multiple points near the waist of the main measurement light path and the corresponding spot radius size. The final waist position and waist spot radius size are then obtained through calculation and software fitting.

[0050] The working principle of this invention is as follows:

[0051] like Figure 1 As shown, the optical conversion system 1 and each spot detection system of the present invention are connected sequentially through vacuum tubes, and each spot detection system is equipped with a cross-section detector and a camera. The first spot detection system 3, located near the optical conversion system 1, is equipped with an extractor 301. The original Gaussian beam, after being converted by the optical conversion system 1 and the extractor 301, forms a measurement main optical path parallel to the original Gaussian beam. Figures 2-3 As shown, each cross-section detector includes a fluorescent element 12 that can move in and out of the main measurement optical path. After the fluorescent element 12 enters the main measurement optical path, the fluorescent light paths branching off are respectively injected into the corresponding cameras to form measurement spots. Then, the system of the present invention calculates the M of the original Gaussian beam by calculating the size of the measurement spots obtained by each camera. 2 Factors and other parameters.

[0052] like Figure 4 As shown in the figure, the symbols and the solution parameters of this invention are explained in detail below:

[0053] Waist radius W 01 The propagation of a laser beam follows the laws of Gaussian beams. The waist refers to the narrowest part of the Gaussian beam, and the waist radius refers to the radius of the cross-sectional circle at the narrowest part.

[0054] Light source position Z1: distance from the light source beam waist to the focusing optical element 102 (super toroidal mirror).

[0055] Far-field divergence angle θ: The propagation characteristic of a Gaussian beam is that it spreads at a specific angle along the propagation direction at a distance. This angle is the far-field divergence angle of the beam.

[0056] M 2Factor: Due to diffraction and other factors, the actual beam propagation characteristics differ from the ideal Gaussian propagation characteristics. By definition, M is the product of the actual beam waist width and the far-field beam divergence angle divided by the product of the ideal fundamental mode Gaussian beam waist width and the far-field beam divergence angle. 2 factor.

[0057] Figure 4 In the symbols, the last number of the subscript indicates the object side (1) and the image side (2).

[0058] like Figure 1 As shown, the present invention includes a first spot detection system 3, a second spot detection system 5, and a third spot detection system 7. The detection process of the present invention is as follows:

[0059] Before the light is transmitted, the gas in each vacuum chamber and pipe is extracted using the first vacuum generating component 306 and the second vacuum generating component 707. When the set vacuum level is reached in the chamber and pipe, the vacuum linear displacement stage 101 of the optical conversion system 1 moves to bring the focusing optical element 102 into the incident original Gaussian beam. The original Gaussian beam is converted by the optical conversion system 1 and the lead-out mirror 301 to form the measurement main optical path (converted Gaussian beam) parallel to it.

[0060] Then, the fluorescent element 12 of the first cross-section detector 303 enters the main measurement optical path, and the fluorescent element 12 of the first cross-section detector 303 forms the first fluorescent optical path, which is incident on the first camera 308 to obtain the first measurement spot radius size W. 21 After the measurement is completed, the fluorescent element 12 of the first cross-section detector 303 cuts out the main measurement optical path, and the fluorescent element 12 of the second cross-section detector 503 enters the main measurement optical path. The fluorescent element 12 of the second cross-section detector 503 forms a second fluorescent optical path that enters the second camera 505 to obtain the second measurement spot radius size W. 22 The distance between the first cross-section detector 303 and the second cross-section detector 503 is ΔZ. Since the positions of the first two cross-section detectors are relatively far from the beam waist, they belong to the far field of the Gaussian beam, and the far field divergence angle can be directly obtained. Figure 4 And the divergence angle θ2 of the transformed Gaussian beam (i.e., the main measurement optical path) is calculated using the following formula (1):

[0061]

[0062] Then, according to the following equation (2), the divergence angle θ1 of the original Gaussian beam is converted using the scaling relationship:

[0063]

[0064] Then, the fluorescent element 12 of the second cross-section detector 503 also exits the main measurement optical path, and the fluorescent element 12 of the third cross-section detector 703 enters the main measurement optical path. The third cross-section detector 703, through the length adjustment tube 602, obtains the beam waist size at multiple points near the beam waist of the main measurement optical path (i.e., the converted Gaussian beam). The beam waist position Z2 and size W of the main measurement optical path are then fitted using the following formula (3) and the software's built-in fitting algorithm. 02 Specifically, the beam waist distance and corresponding spot radius of multiple points near the beam waist are obtained by adjusting the length of the length adjustment tube 602, which is equivalent to obtaining several independent variables Z and their corresponding W2(Z). Substituting these values ​​into the following formula (3), multiple sets of Z2 and W2 are determined. 02 The values ​​are then used to obtain the final beam waist position Z2 and spot radius size W through the software's built-in fitting algorithm. 02 The software is a technology known in the art. In addition, in the following formula (3), λ is the laser wavelength, which is a constant.

[0065]

[0066] Then, the original beam waist position Z1 and size W are obtained according to the following equations (4) and (5). 01 :

[0067]

[0068]

[0069] In equation (4) above, f is the focal length of the focusing optical element 102 (super toroidal mirror), which is a constant.

[0070] Finally, the M of the original Gaussian beam is calculated using the following formula (6). 2 factor:

[0071]

[0072] In summary, this invention obtains the distance Z1 from the source point to the toroidal mirror and the beam waist radius W of the original Gaussian beam by measuring the Gaussian beam information after conversion by the optical conversion system 1 and the extractor 301. 01 and M 2 factor.

Claims

1. A laser M based on beam Gaussian transmission transformation 2 Factor measurement device, characterized in that: The system includes an optical conversion system (1), a first spot detection system (3), a second spot detection system (5), and a third spot detection system (7) connected sequentially via a vacuum pipe. The optical conversion system (1) is equipped with a movable focusing optical element (102). The first spot detection system (3) includes a first cross-section detector (303), a first camera (308), and an extraction mirror (301). The second spot detection system (5) includes a second cross-section detector (503) and a second camera (505). The third spot detection system (7) includes a third cross-section detector (703) and a third camera (706). The original Gaussian beam is converted by the focusing optical element (102) and the lead-out mirror (301) to form the main measurement optical path. The first cross-section detector (303), the second cross-section detector (503) and the third cross-section detector (703) are all equipped with fluorescent elements (12) that can enter and exit the main measurement optical path. After the fluorescent elements (12) enter the main measurement optical path, they form a fluorescent optical path that is injected into the corresponding camera. A length adjustment tube (602) is provided on the vacuum pipe between the second spot detection system (5) and the third spot detection system (7). The third cross-section detector (703) is located at the waist of the main measurement optical path. The focusing optical element (102) is a toroidal mirror; The first spot detection system (3) near the optical conversion system (1) is equipped with an extractor (301), and the original Gaussian beam is converted by the optical conversion system (1) and the extractor (301) to form a measurement main optical path parallel to the original Gaussian beam; The length adjusting tube (602) is a corrugated tube.

2. The laser M based on beam Gaussian transmission transformation according to claim 1 2 Factor measurement device, characterized in that: The optical conversion system (1) has a vacuum linear displacement stage (101) inside its vacuum cavity, and a focusing optical element (102) is provided on the vacuum linear displacement stage (101).

3. The laser M based on beam Gaussian transmission transformation according to claim 2 2 Factor measurement device, characterized in that: The optical conversion system (1) has an observation window (103) and a vacuum gauge (104) on the outside of the vacuum cavity.

4. The laser M based on beam Gaussian transmission transformation according to claim 1 2 Factor measurement device, characterized in that: The vacuum chamber of the first spot detection system (3) is provided with a first window (307), a first vacuum gauge (304) and a first angle valve (305), wherein the first window (307) is aligned with the first camera (308) and the first angle valve (305) is connected to the first vacuum generating component (306).

5. The laser M based on beam Gaussian transmission transformation according to claim 1 2 Factor measurement device, characterized in that: The second spot detection system (5) has a second window (501) and a second vacuum gauge (504) on the outside of the vacuum cavity, wherein the second window (501) is aligned with the second camera (505).

6. The laser M based on beam Gaussian transmission transformation according to claim 1 2 Factor measurement device, characterized in that: The vacuum chamber of the third spot detection system (7) is provided with a third window (705), a third vacuum gauge (704) and a second angle valve (701), wherein the third window (705) is aligned with the third camera (706) and the second angle valve (701) is connected to the second vacuum generating component (707).

7. The laser M based on beam Gaussian transmission transformation according to claim 1 2 Factor measurement device, characterized in that: The first cross-section detector (303), the second cross-section detector (503) and the third cross-section detector (703) have the same structure, each including a fluorescent element (12), a mounting base (10), an adjustment base (11) and an adjustment base driving mechanism. The fluorescent element (12) is disposed on the mounting base (10), the upper end of the mounting base (10) is fixedly connected to the adjustment base (11), and the adjustment base (11) is driven to move by the adjustment base driving mechanism.

8. A laser M based on beam Gaussian transmission transformation according to claim 1 2 The measurement method of the factor measurement device is characterized by: During measurement, the fluorescent element (12) of the first cross-section detector (303) first enters the main measurement optical path, and the first camera (308) obtains the radius size of the first measurement spot. Then, the fluorescent element (12) of the first cross-section detector (303) exits, and the fluorescent element (12) of the second cross-section detector (503) enters the main measurement optical path, and the second camera (505) obtains the second measurement spot radius size. The distance between the first cross-section detector (303) and the second cross-section detector (503) is The divergence angle of the main optical path is obtained according to the following formula (1). : （1）； Then, the divergence angle of the original Gaussian beam is obtained according to the following formula (2). : （2）； Then the fluorescent element (12) of the second cross-section detector (503) exits, and the fluorescent element (12) of the third cross-section detector (703) enters the main optical path for measurement. The beam waist distance Z and the corresponding spot radius of multiple points are obtained by length adjustment through the length adjustment tube (602). Substitute into the following formula (3) to determine multiple groups and The value is calculated using software fitting to obtain the final waist position. and size : （3）； In equation (3) above, λ is the laser wavelength; Then, the original beam waist position is obtained according to the following equations (4) and (5). and size : （4）； （5）； In equation (5) above, f is the focal length of the focusing optical element 102; Then, the M of the original Gaussian beam is obtained according to the following formula (6). 2 factor: （6）。 9. The laser M based on beam Gaussian transmission transformation according to claim 8 2 The measurement method of the factor measurement device is characterized by: Before measurement, the optical conversion system (1), the first spot detection system (3), the second spot detection system (5), the third spot detection system (7) and each vacuum pipe are evacuated to a set vacuum level. After the set vacuum level is reached, the focusing optical element (102) in the optical conversion system (1) moves into the incident original Gaussian beam. The original Gaussian beam is converted by the focusing optical element (102) and the lead-out mirror (301) to form the main optical path for measurement.

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