Multi-axis interferometer parallelism detection system and detection method

Abstract

The invention provides a multi-axis interferometer parallelism detection system and detection method. The detection method comprises the following steps: after being shaped, a laser beam is divided into a first to-be-detected light beam and a second to-be-detected light beam by a multi-axis interferometer; adjusting a camera mirror surface in the detection module to be vertical to the x direction; the detection module obtains near-end imaging information and far-end imaging information of the first to-be-detected light beam and the second to-be-detected light beam; calculating the parallelism of the second to-be-detected light beam and the first to-be-detected light beam; and when not parallel, calculating an included angle for angle compensation. Through imaging comparison of the near end and the far end, the light beam parallelism of the multi-axis interferometer is accurately measured, and the effectiveness of the measurement result is high; meanwhile, a reflection module is arranged to ensure that the camera is perpendicular to the optical axis of the first to-be-detected light beam, and measurement accuracy and effectiveness are improved; in addition, the light beam converging tool converges the light beams, so that the camera does not need to move when imaging the two to-be-detected light beams, and the detection convenience is improved; finally, the imaging beam radius is set to adjust the beam collimation effect, and the detection precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser measurement, and particularly relates to a multi-axis interferometer parallelism detection system and a detection method. Background Art

[0002] With the development and demands of information science semiconductor technology, the requirements for precision in various aspects such as processing, alignment, and detection of various semiconductor devices, instruments, and maintenance systems are increasing day by day, resulting in higher and higher requirements for high-precision detection technologies. Currently, for the detection of nanometer-level precision, a laser interferometer is usually used. In the manufacturing and use of a multi-axis interferometer, the beam parallelism is an important index of the multi-axis interferometer, which will directly affect the measurement accuracy of the multi-axis interferometer.

[0003] Although it is difficult to achieve a completely parallel setting of the beam parallelism of the multi-axis interferometer, if the parallelism between each optical axis can be accurately measured through high-precision measurement technology, in the subsequent data processing and displacement calculation processes, the influence caused by the non-parallelism of the beams can be compensated or corrected by using the parallelism between each optical axis. Thus, even if there is a certain deviation in the beam parallelism during the manufacturing process, the deviation can be corrected through later data processing, thereby ensuring the accuracy of the final measurement result.

[0004] However, in the prior art, no effective detection method has been found for measuring the beam parallelism between the axes of a multi-axis interferometer. In traditional methods, the beam parallelism is usually subjectively judged by visual inspection, resulting in low measurement accuracy and poor repeatability of the actual obtained beam parallelism, and it is difficult to improve the measurement result accuracy of the multi-axis interferometer.

[0005] Therefore, there is an urgent need for a structure or method that can effectively, accurately, and with high precision measure the parallelism between the beams of a multi-axis interferometer.

[0006] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art, and it cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0007] In view of the above-mentioned drawbacks of the prior art, the purpose of the present invention is to provide a multi-axis interferometer parallelism detection system and a detection method, which are used to solve the problems of low measurement accuracy and poor effectiveness of the beam parallelism between multi-axis interferometers in the prior art.

[0008] To achieve the above purpose, the present invention provides a multi-axis interferometer parallelism detection system, and the detection system includes: a light source module, a beam shaping module, a multi-axis interferometer, a detection module, and a calculation module; The laser beam emitted by the light source module is shaped into a collimated single-polarized incident light by the beam shaping module. The incident light enters the multi-axis interferometer and is divided into n beams, including 1 first beam to be detected and n - 1 second beams to be detected, where n is an integer greater than or equal to 2. A preset x direction is set, and the optical axis of the first beam to be detected is parallel to the x direction. The detection module is used to receive and measure the proximal imaging information and the distal imaging information of the first beam to be detected and the second beams to be detected on the imaging surface perpendicular to the x direction in the proximal position area and the distal position area. The distance between the distal position area and the multi-axis interferometer in the x direction is greater than the distance between the proximal position area and the multi-axis interferometer in the x direction. The calculation module is connected to the detection module and is used to obtain the parallelism between the second beam to be detected and the first beam to be detected based on the proximal imaging information and the distal imaging information.

[0009] Optionally, the multi-axis interferometer parallelism detection system further includes a displacement device. The detection module is located on the displacement device, and the displacement device is used to drive the detection module to move between the distal position area and the proximal position area, and / or the displacement device is used to drive the detection module to move within the distal position area or the proximal position area.

[0010] Optionally, the multi-axis interferometer includes n exit holes. The detection system further includes a beam convergence tooling, which includes a convergence tooling plate and n - 1 rhombic prisms. The convergence tooling plate includes n light passing holes, and the positions of the n light passing holes correspond to the positions of the n exit holes one by one. The n - 1 rhombic prisms are respectively fixed on the side of the n - 1 light passing holes away from the multi-axis interferometer. The n beams emitted by the multi-axis interferometer can respectively pass through the corresponding light passing holes from the n exit holes. The first beam to be detected enters the detection module after passing through the corresponding light passing hole, and the n - 1 second beams to be detected enter the detection module after passing through the corresponding light passing holes and the rhombic prisms respectively.

[0011] Optionally, the beam shaping module includes a linear polarizer, a converging lens, an exit hole, and a collimating lens arranged in sequence along the x direction. The laser beam emitted by the light source module is adjusted to a single-polarized light after entering the linear polarizer. The single-polarized light is converged into a converging beam after entering the converging lens. The converging beam exits as a collimated beam from the exit hole and is collimated after entering the collimating lens to obtain a collimated single-polarized incident light.

[0012] Optionally, the collimating lens has the same parameters as the converging lens. The focal length of the converging lens is f, the aperture of the light exit hole is D1, and the beam diameter of the laser beam incident on the beam shaping module is D2, and .

[0013] Optionally, the detection module includes a positioning hole and a camera. The positioning hole is used to image the beam incident on the camera in the central area of the camera.

[0014] Optionally, the multi-axis interferometer parallelism detection system further includes a reflection module. The reflection module includes a camera mirror bracket detachably mounted on the camera mirror surface of the detection module and a reflector. The reflector is mounted on the side of the camera mirror bracket away from the camera. The first beam to be detected can be reflected by the reflector to the multi-axis interferometer.

[0015] The present invention also provides a method for detecting the parallelism of a multi-axis interferometer. The detection method uses any one of the above-mentioned multi-axis interferometer detection systems to detect the parallelism of the multi-axis interferometer. The detection method includes: The light source module emits a laser beam. The laser beam is shaped into a collimated single-polarized incident light by the beam shaping module. After the incident light enters the multi-axis interferometer, it is divided into 1 first beam to be detected and n - 1 second beams to be detected, where n is an integer greater than or equal to 2; Adjust the mirror angles of the cameras in the detection module so that the mirror surfaces of the cameras are all perpendicular to the first beam to be detected; The detection module receives and measures the proximal imaging information of the first beam to be detected and each of the second beams to be detected on the imaging surface perpendicular to the first beam to be detected in the proximal position area; the detection module receives and measures the distal imaging information of the first beam to be detected and each of the second beams to be detected on the imaging surface perpendicular to the first beam to be detected in the distal position area; The calculation module determines the parallelism between each of the second beams to be detected and the first beam to be detected according to the proximal imaging information and the distal imaging information; when it is determined that there is a second beam to be detected that is not parallel to the first beam to be detected, calculate the angle θ between the second beam to be detected and the first beam to be detected, and perform angle compensation on the exit angle of the second beam to be detected according to the calculated angle θ.

[0016] Optionally, the method for the detection module to receive and measure the proximal imaging information includes: When using a beam convergence tooling to move the n - 1 second beams to be detected emitted by the multi-axis interferometer to a preset imaging position fixed in the proximal position area of the detection module, the detection module can simultaneously image at least one of the 1 first beam to be detected and the n - 1 second beams to be detected; Fix the detection module at the preset imaging position within the proximal position area. The detection module receives and measures the proximal imaging information, which is the distance A1 between the imaging center position coordinates of the first beam to be detected and the corresponding one of the second beams to be detected. The method for the detection module to receive and measure the distal imaging information includes: When using a beam convergence tooling to move n - 1 of the second beams to be detected emitted by the multi - axis interferometer to the preset imaging position where the detection module is fixed within the distal position area, the detection module can simultaneously image at least one of the second beams to be detected among one first beam to be detected and n - 1 second beams to be detected. Fix the detection module at the preset imaging position within the distal position area. The detection module receives and measures the distal imaging information, which is the distance A2 between the imaging center position coordinates of the first beam to be detected and the corresponding one of the second beams to be detected. Calculate whether A1 is equal to A2. If A1 is equal to A2, it is determined that the first beam to be detected is parallel to the corresponding one of the second beams to be detected. If A1 is not equal to A2, calculate the included angle θ between the first beam to be detected and the corresponding one of the second beams to be detected, and perform angle compensation according to the calculated included angle θ corresponding to the emission angle of the second beam to be detected.

[0017] Optionally, the method for the detection module to receive and measure the proximal imaging information includes: After moving the detection module perpendicular to the x - direction within the proximal position area until the first beam to be detected is imaged at the center point of the camera, the detection module moves a preset distance perpendicular to the x - direction with this position as the center position and then receives and measures the proximal imaging information, which is the distance A1 between the imaging coordinate of one of the n - 1 second beams to be detected on the camera and the center point. The preset distance is the designed optical axis spacing between the first beam to be detected and this second beam to be detected. The method for the detection module to receive and measure the distal imaging information includes: After moving the detection module perpendicular to the x - direction within the distal position area until the first beam to be detected is imaged at the center point of the camera, the detection module moves the designed optical axis spacing perpendicular to the x - direction with this position as the center position and then receives and measures the distal imaging information, which is the distance A2 between the imaging coordinate of one of the n - 1 second beams to be detected on the camera and the center point. Calculate whether A1 is equal to A2. If A1 is equal to A2, then determine that the first beam to be detected is parallel to the corresponding one of the second beams to be detected. If A1 is not equal to A2, then calculate the included angle θ between the first beam to be detected and the corresponding one of the second beams to be detected, and perform angle compensation on the exit angle of the second beam to be detected according to the calculated included angle θ.

[0018] Optionally, the method for calculating the included angle θ between the first beam to be detected and the corresponding one of the second beams to be detected is as follows: The calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module, and calculates the included angle between the second beam to be detected and the first beam to be detected according to A1 and A2. , where B is the pixel size of the camera in the detection module, L1 is the distance between the imaging position of the detection module in the proximal position area and the exit hole of the multi-axis interferometer, and L2 is the distance between the imaging position of the detection module in the distal position area and the exit hole of the multi-axis interferometer.

[0019] Optionally, the method for adjusting the mirror angle of the camera in the detection module includes: A fixed reflection module is detachably installed on the detection module. The reflection module includes a camera mirror bracket and a reflecting mirror. The camera mirror bracket is installed on the camera mirror of the detection module, and the reflecting mirror is located on the camera mirror bracket so that the reflecting mirror is parallel to the mirror of the camera. The detection module is moved from the first position in the distal position area or the proximal position area to the second position perpendicular to the first beam to be detected. The distance between the first position and the second position is fixed. The reflecting mirror fixedly installed with the detection module can receive the first beam to be detected at both the first position and the second position, and the first reflected beam and the second reflected beam after the first beam to be detected is reflected by the reflecting mirror at the first position and the second position can both be received by the multi-axis interferometer. The multi-axis interferometer receives the first reflected beam reflected back from the first position by the first beam to be detected and the second reflected beam reflected back from the second position by the first beam to be detected, and measures the reflection displacement between the first reflected beam and the second reflected beam received by the multi-axis interferometer. Rotate the mirror angle of the camera installed parallel to the reflecting mirror until the obtained reflection displacement is the smallest, determine that the mirror of the camera is perpendicular to the first beam to be detected at this time, and fix the angle position of the camera mirror at this time. After the adjustment of the camera is completed, remove the reflection module.

[0020] As above, the multi-axis interferometer parallelism detection system and detection method of the present invention have the following beneficial effects: By comparing the imaging information of the proximal and distal detection modules, the present invention can accurately measure the beam parallelism of the multi-axis interferometer, with high measurement accuracy, strong repeatability, and strong validity of the measurement results; The present invention adjusts the perpendicular relationship between the camera mirror surface and the optical axis of the first beam to be detected through the reflection modules arranged correspondingly at the distal and proximal ends, further ensuring the accuracy and repeatability of the beam parallelism measurement; The present invention converges the beams of the multi-axis interferometer in a smaller area through a beam convergence tooling, enabling the camera to image two beams to be detected without moving, thereby improving the detection convenience; The present invention adjusts the collimation effect of the beam shaping module through the imaging beam radii of the proximal and distal detection modules, further improving the detection accuracy of the beam parallelism of the multi-axis interferometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic structural diagram of the multi-axis interferometer parallelism detection system in Embodiment 1 of the present invention.

[0022] Figure 2 Shown is a schematic structural diagram of the multi-axis interferometer parallelism detection system in an example of Embodiment 1 of the present invention in the direction of the multi-axis interferometer outgoing beam.

[0023] Figure 3 Shown is a schematic structural diagram of the beam shaping module of the multi-axis interferometer parallelism detection system in Embodiment 1 of the present invention.

[0024] Figure 4 Shown is a schematic structural diagram of the detection module of the multi-axis interferometer parallelism detection system in Embodiment 1 of the present invention.

[0025] Figure 5 Shown is a schematic structural diagram of the reflection module of the multi-axis interferometer parallelism detection system in Embodiment 1 of the present invention installed in the detection module.

[0026] Figure 6 Shown is a schematic structural diagram presented by the detection module and the reflection module in the multi-axis interferometer parallelism detection system of Embodiment 1 of the present invention.

[0027] Figure 7 Shown is a schematic structural diagram presented by the detection module and the reflection module in the proximal position area in the multi-axis interferometer parallelism detection method of Embodiment 1 of the present invention.

[0028] Figure 8 Shown is a schematic structural diagram presented by the detection module and the reflection module in the distal position area in the multi-axis interferometer parallelism detection method of Embodiment 1 of the present invention.

[0029] Figure 9It shows a schematic diagram of the principle for calculating the included angle in the parallelism detection method of the multi-axis interferometer according to Embodiment 1 of the present invention.

[0030] Figure 10 It shows a schematic diagram of the principle for calculating the approximate included angle in the parallelism detection method of the multi-axis interferometer according to Embodiment 1 of the present invention.

[0031] Figure 11 It shows a schematic diagram of adjusting the angle of the camera mirror surface in the parallelism detection method of the multi-axis interferometer according to Embodiment 1 of the present invention.

[0032] Figure 12 It shows a schematic diagram of the principle for judging the slope of the camera mirror surface in the parallelism detection method of the multi-axis interferometer according to Embodiment 1 of the present invention.

[0033] Figure 13 It shows a schematic structural diagram of the light-emitting hole of the multi-axis interferometer in the parallelism detection system of the multi-axis interferometer according to Embodiment 2 of the present invention.

[0034] Figure 14 It shows a schematic structural diagram of the light beam converging tooling in the parallelism detection system of the multi-axis interferometer according to Embodiment 2 of the present invention.

[0035] Figure 15 It shows a schematic structural diagram of the outgoing light beam of the light beam converging tooling in the parallelism detection system of the multi-axis interferometer according to Embodiment 2 of the present invention.

[0036] Figure 16 It shows a schematic diagram of the principle of the parallelism detection method of the multi-axis interferometer according to Embodiment 2 of the present invention.

[0037] Explanation of the reference numerals in the drawings 11. Light source module; 12. Beam shaping module; 13. Multi-axis interferometer; 14. Angle deflection structure; 15. Proximal position area; 16. Distal position area; 17. Detection module; 17a. Proximal detection module; 17b. Distal detection module; 18. Reflection module; 18a. Proximal reflection module; 18b. Distal reflection module; 21. Linear polarizer; 22. Converging lens; 23. Light-emitting hole; 24. Collimating lens; 30, 31, 32. Light-emitting holes; 41. Positioning hole; 42. Camera; 45. Reflector; 451. First reflected light beam; 452. Second reflected light beam; 46. Camera mirror support; 51. Laser beam; 52. Single-polarized light; 53. Converging light beam; 54. Collimated light beam; 55. Incident light; 56. First beam to be detected; 57, 58. Second beams to be detected; 71. Converging tooling plate; 72, 73. Rhombic prisms; 74, 75, 76. Light-passing holes. Detailed implementation manners

[0038] The embodiments of the present invention will be described below through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0039] When detailing the embodiments of the present invention, for ease of explanation, the schematic diagrams showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0040] For convenience of description, spatial relationship terms such as "beneath", "below", "lower", "under", "above", "on" may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatial relationship terms are intended to encompass other directions of the device in use or operation in addition to the directions depicted in the drawings.

[0041] In the context of the present application, the structure in which the first feature is "above" the second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0042] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation may be arbitrarily changed, and the component layout type may also be more complex; the numerical ranges given in the present invention default to include the two boundary values of the numerical range without special limitations. Embodiment 1

[0043] This embodiment provides a multi-axis interferometer 13 parallelism detection system, as Figures 1 to 8 shown, the detection system includes: a light source module 11, a beam shaping module 12, a multi-axis interferometer 13, a detection module 17, and a calculation module (not shown); The laser beam 51 emitted by the light source module 11 is shaped into a collimated single-polarized incident light 55 by the beam shaping module 12. The incident light 55 enters the multi-axis interferometer 13 and is divided into n beams, including 1 first beam to be detected 56 and n - 1 second beams to be detected 57, where n is an integer greater than or equal to 2. A preset x direction is set, and the optical axis of the first beam to be detected 56 is parallel to the x direction. The detection module 17 is configured to receive and measure the proximal imaging information and the distal imaging information of the first beam to be detected 56 and the second beam to be detected 57 on the imaging plane perpendicular to the x direction within the proximal position region 15 and the distal position region 16. The distance between the distal position region 16 and the multi-axis interferometer 13 along the x direction is greater than the distance between the proximal position region 15 and the multi-axis interferometer 13 along the x direction. The calculation module is connected to the detection module 17 and is configured to obtain the parallelism between the second beam to be detected 57 and the first beam to be detected 56 based on the proximal imaging information and the distal imaging information.

[0044] In the present invention, by setting the detection module 17 to measure the proximal imaging information and the distal imaging information of the first beam to be detected 56 and the second beam to be detected 57 on the imaging plane perpendicular to the x direction within the proximal position region 15 and the distal position region 16, when the first beam to be detected 56 and the second beam to be detected 57 are not parallel, the distance between the first beam to be detected 56 and the second beam to be detected 57 is different in the direction perpendicular to the first beam to be detected 56 at different positions (the proximal position region 15 and the distal position region 16). Therefore, it is possible to determine whether the first beam to be detected 56 and the second beam to be detected 57 are parallel based on whether the distances between the first beam to be detected 56 and the second beam to be detected 57 obtained from the proximal imaging information and the distal imaging information are equal.

[0045] Specifically, Figure 1 Only 1 first beam to be detected 56 and 1 second beam to be detected 57 are shown in the figure. In practical applications, the number of the second beams to be detected 57 can be set according to requirements.

[0046] Specifically, Figure 1 In the figure, a dotted line guide between the beam and the detection module 17 is set to show the movement of the detection module 17 between two different positions for imaging the first beam to be detected 56 and the second beam to be detected 57. In actual detection, the detection module 17 needs to be positioned according to the imaging requirements in the detection method, and it is not necessary to image the beam after offsetting.

[0047] In one embodiment, as Figure 2As shown, the first beam to be detected 56 and the second beam to be detected 57 emitted by the multi-axis interferometer 13 can change the optical path direction after passing through the angle deflection structure 14 (such as a reflecting mirror, etc.), and then pass through the preset proximal position area 15 and distal position area 16 for imaging. At this time, the preset x direction is the optical axis direction parallel to the incident proximal position area 15 and distal position area 16 of the first beam to be detected 56; when the site size is limited, the arrangement method in this embodiment can be adopted to shorten the optical path and facilitate measurement.

[0048] In one embodiment, the multi-axis interferometer parallelism detection system further includes a displacement device (not shown in the figure); the detection module 17 is located on the displacement device, and the displacement device is used to drive the detection module 17 to move between the distal position area 16 and the proximal position area 15, and / or the displacement device is used to drive the detection module 17 to move within the distal position area 16 or within the proximal position area 15.

[0049] In one embodiment, the displacement device is a nanoscale piezoelectric displacement stage.

[0050] The present invention moves the detection module 17 by setting the displacement device, so that the moving distance and direction of the detection module 17 can be precisely controlled, and the obtained measurement result is more accurate.

[0051] In one embodiment, the light source module 11 is a dual-frequency laser, the emitted laser beam 51 is orthogonally polarized light, and it has interference rings itself.

[0052] In one embodiment, as Figure 3 shown, the beam shaping module 12 includes a linear polarizer 21, a converging lens 22, an output aperture 23, and a collimating lens 24 arranged in sequence along the x direction; The laser beam 51 emitted by the light source module 11 is adjusted to single-polarized light 52 after entering the linear polarizer 21. The single-polarized light 52 is converged into a converging beam 53 after entering the converging lens 22. The converging beam 53 exits from the output aperture 23 as a collimated beam 54, and is collimated after entering the collimating lens 24 to obtain a collimated single-polarized incident light 55.

[0053] The present invention sequentially polarizes, converges, and collimates the laser beam 51 by setting the linear polarizer 21, the converging lens 22, the output aperture 23, and the collimating lens 24 in the beam shaping module 12, so as to obtain the incident light 55 emitted when the multi-axis interferometer 13 is normally used, and shape the messy and irregular beam into a better circular regular light spot, which is convenient for collecting the beam imaging information when detecting parallelism, improves the detection accuracy, and enables the laser after detecting parallelism to be used in actual production.

[0054] Specifically, the beam shaping module 12 is located between the output port of the light source module 11 and the input port of the multi-axis interferometer 13.

[0055] In one embodiment, the linear polarizer 21 is used to adjust the laser beam 51 into a horizontally polarized light, avoiding the interference fringes produced by the double-polarized light beam emitted by the light source module 11 from affecting image recognition, and further ensuring the accuracy and effectiveness of the parallelism detection result.

[0056] In one embodiment, as Figure 3 shown, the collimating lens 24 and the converging lens 22 have the same parameters. The focal length of the converging lens 22 is f, the aperture of the light exit hole 23 is D1, and the beam diameter of the laser beam 51 of the incident beam shaping module 12 is D2, and .

[0057] Specifically, λ is the wavelength of the laser beam 51.

[0058] In one embodiment, the position of the collimating lens 24 is adjusted to achieve the best collimation effect. Specifically, the collimated beam 54 emitted from the collimating lens 24 is directly imaged by the detection module 17 in the proximal position area 15 and the distal position area 16 respectively to obtain a proximal collimated image and a distal collimated image. In the calculation module, 1 / e of the beam intensities of the proximal collimated image and the distal collimated image 2 is used as the beam radius. The difference between the beam radius of the proximal collimated image and the beam radius of the distal collimated image is compared. The collimating lens 24 is moved back and forth along the optical axis of the collimated beam 54. When the difference between the beam radius of the obtained proximal collimated image and the beam radius of the distal collimated image is the smallest, it indicates that the best collimation effect is achieved. Fix the position of the collimating lens 24 at this time to obtain the incident light 55 of the incident multi-axis interferometer 13. Specifically, e is an irrational constant.

[0059] By setting the relationship between the aperture of the light exit hole 23 and the beam diameter of the laser beam 51, the present invention can further optimize the collimation effect of the beam shaping module 12, thereby improving the detection accuracy of the beam parallelism of the multi-axis interferometer 13.

[0060] In one embodiment, as Figure 4 shown, the detection module 17 includes a positioning hole 41 and a camera 42. The positioning hole 41 is used to image the beam incident on the camera 42 in the central region of the camera 42.

[0061] By setting the positioning hole 41 to image the beam incident on the camera 42 in the central region of the camera 42, the present invention defines the position where the beam to be detected reaches the camera 42, thereby ensuring the repeatability of the detection result. The effectiveness of the result can be verified by multiple measurements, and a more accurate detection result can be obtained.

[0062] Specifically, Figure 1The positioning holes 41 and the camera 42 in the detection module 17 that moves between two different positions are shown, rather than two detection modules 17 placed simultaneously.

[0063] In one embodiment, as Figure 5 and Figure 7 shown, the multi-axis interferometer parallelism detection system further includes a reflection module 18. The reflection module 18 includes a camera mirror bracket 46 detachably mounted on the mirror surface of the camera 42 in the detection module 17 and a reflecting mirror 45. The reflecting mirror 45 is mounted on the side of the camera mirror bracket 46 away from the camera 42. The first beam to be detected 56 can be reflected by the reflecting mirror 45 to the multi-axis interferometer 13.

[0064] In the present invention, by providing the camera mirror bracket 46 detachably mounted on the mirror surface of the camera 42 and the reflecting mirror 45 placed on the camera mirror bracket 46 in the reflection module 18, the camera mirror bracket 46 provides a fixed support for the reflecting mirror 45 and makes the reflecting mirror 45 parallel to the mirror surface of the camera 42. Thus, it is possible to use the reflected light of the reflecting mirror 45 reflected back to the multi-axis interferometer 13 to determine whether the mirror surface of the camera 42 is perpendicular to the first beam to be detected 56, so as to reduce the distance difference between the first beam to be detected 56 and the second beam to be detected 57 to the detection module 17 caused by the slope error of the installation of the camera 42, ensure that the mirror surface of the camera 42 is perpendicular to 56, and thus make the imaging information obtained by the camera 42 more accurately reflect the beam parallelism of the multi-axis interferometer 13.

[0065] Preferably, the accuracy of the reflecting mirror 45 is at the nanometer level.

[0066] In one embodiment, as Figure 6 shown, in the proximal position area 15 and the distal position area 16, there are corresponding proximal detection modules 17a, proximal reflection modules 18a, distal detection modules 17b and distal reflection modules 18b respectively. The proximal detection modules 17a and proximal reflection modules 18a obtain proximal imaging information, and the distal detection modules 17b and distal reflection modules 18b obtain distal imaging information. When collecting the distal imaging information, the proximal detection modules 17a and proximal reflection modules 18a are removed.

[0067] In another embodiment, as Figures 7 - 8 shown, only one detection module 17 and one reflection module 18 are provided, and they move between the proximal position area 15 and the distal position area 16 to obtain proximal imaging information and distal imaging information respectively. As Figure 7 shown is a schematic diagram when the detection module 17 and the reflection module 18 obtain proximal imaging information in the proximal position area 15, and as Figure 8 shown is a schematic diagram when the detection module 17 and the reflection module 18 obtain distal imaging information in the distal position area 16.

[0068] As shown Figures 7 - 8 in the figure, this embodiment further provides a method for detecting the parallelism of the multi-axis interferometer 13. The detection method uses the multi-axis interferometer 13 detection system of any of the above to detect the parallelism of the multi-axis interferometer 13. The detection method includes: The light source module 11 emits a laser beam 51. The laser beam 51 is shaped into a collimated single-polarized incident light 55 by the beam shaping module 12. After the incident light 55 enters the multi-axis interferometer 13, it is divided into one first beam to be detected 56 and n - 1 second beams to be detected 57, where n is an integer greater than or equal to 2; Adjust the mirror angles of the cameras 42 in the detection module 17 so that the mirrors of the cameras 42 are all perpendicular to the first beam to be detected 56; As shown Figure 7 in the figure, the detection module 17 receives and measures the proximal imaging information of the first beam to be detected 56 and each second beam to be detected 57 on the imaging surface perpendicular to the first beam to be detected 56 in the proximal position area 15; as shown Figure 8 in the figure, the detection module 17 receives and measures the distal imaging information of the first beam to be detected 56 and each second beam to be detected 57 on the imaging surface perpendicular to the first beam to be detected 56 in the distal position area 16; The calculation module determines the parallelism between each second beam to be detected 57 and the first beam to be detected 56 according to the proximal imaging information and the distal imaging information; when a second beam to be detected 57 that is not parallel to the first beam to be detected 56 is determined, calculate the angle θ between the second beam to be detected 57 and the first beam to be detected 56, and perform angle compensation on the outgoing angle of the second beam to be detected 57 according to the calculated angle θ.

[0069] Specifically, the proximal imaging information of the first beam to be detected 56 and each second beam to be detected 57 on the imaging surface perpendicular to the first beam to be detected 56 in the proximal position area 15 is the distance between the centers of the light spot images of the cameras 42 in the detection module 17 of the first beam to be detected 56 and the second beam to be detected 57 in the proximal position area 15.

[0070] Specifically, since the multi-axis interferometer 13 divides the incident light 55 into multiple beams, one of them (the first beam to be detected 56) is used as the reference beam for judging the beam parallelism. The x direction is confirmed according to the optical axis direction of the first beam to be detected 56 as the reference beam, so as to obtain the respective angles between the other beams (n - 1 second beams to be detected 57) and the first beam to be detected 56, thereby calculating and compensating the detection results of the subsequent multi-axis interferometer and correcting the detection results of the multi-axis interferometer.

[0071] The present invention utilizes the proximal position and the distal position to magnify the spacing perpendicular to the x-direction when the first beam to be detected 56 and the second beam to be detected 57 are not parallel, so that the beam angle that is difficult to clearly distinguish with the naked eye is magnified, making the detection result more accurate after the multi-axis interferometer is corrected.

[0072] Preferably, as Figure 7 shown, when the detection module 17 receives the proximal imaging information in the proximal position area 15, the distance between the detection module 17 and the multi-axis interferometer 13 is L1. As Figure 8 shown, when the detection module 17 receives the distal imaging information in the distal position area 16, the distance between the detection module 17 and the multi-axis interferometer 13 is L2, and L2 is much greater than L1.

[0073] In one embodiment, when the detection module 17 receives the proximal imaging information in the proximal position area 15, the distance L1 between the detection module 17 and the multi-axis interferometer 13 is less than 100 mm. When the detection module 17 receives the distal imaging information in the distal position area 16, the distance L2 between the detection module 17 and the multi-axis interferometer 13 is greater than 5000 mm.

[0074] In one embodiment, L2 can be a distance preset in the experiment or a distance measured in the actual experiment. The result obtained by the latter has higher accuracy and can be selected according to the requirements of the detection accuracy.

[0075] It should be noted that the above order does not strictly represent the order of the method for detecting the parallelism of the multi-axis interferometer 13 protected by the present invention, and those skilled in the art can change it according to the actual detection steps.

[0076] In one embodiment, the method for the detection module 17 to receive and measure the proximal imaging information includes: As Figure 7 shown, after the detection module 17 is moved perpendicular to the x-direction within the proximal position area 15 until the first beam to be detected 56 is imaged at the center point of the camera 42, the detection module 17 is moved perpendicular to the x-direction by a preset distance with this position as the center position, and then the proximal imaging information is received and measured. The distance A1 between the imaging coordinate of one of the n-1 second beams to be detected 57 and the center point in the camera 42 is obtained. The preset distance is the designed optical axis spacing between the first beam to be detected 56 and this second beam to be detected 57. The method for the detection module 17 to receive and measure the distal imaging information includes: As Figure 8As shown, after moving the detection module 17 vertically in the x - direction within the remote position area 16 until the first beam to be detected 56 is imaged at the center point of the camera 42, the detection module 17 moves vertically in the x - direction by the designed optical axis spacing with this position as the center position, and then receives and measures the distance A2 between the imaging coordinate of one of the n - 1 second beams to be detected 57 and the center point on the camera 42 for the remote imaging information. Calculate whether A1 and A2 are equal. If A1 and A2 are equal, it is determined that the first beam to be detected 56 and the corresponding one second beam to be detected 57 are parallel. If A1 and A2 are not equal, calculate the angle θ between the first beam to be detected 56 and the corresponding one second beam to be detected 57, and perform angle compensation on the outgoing angle of the second beam to be detected 57 according to the calculated angle θ.

[0077] Through the present invention, a high - precision and highly effective parallelism detection result can be obtained. According to the calculated angle between the beams, the influence caused by non - parallel beams can be compensated or corrected during subsequent data processing and displacement calculation, thus ensuring the accuracy of the final measurement result of the multi - axis interferometer 13.

[0078] Specifically, Figures 7 - 8 Both positions where the detection module 17 is located during the detection process are shown in the same figure. In practice, it is necessary to move the detection module 17 to each position.

[0079] Preferably, as Figure 9 shown, when the detection module 17 moves vertically in the x - direction by a preset distance, the moving direction of the detection module 17 is parallel to the direction of the optical axis spacing connection line E. The direction of the optical axis spacing connection line is the direction of the connection line E between the two designed outgoing holes corresponding to the first beam to be detected 56 and the beam to be detected when they exit from the multi - axis interferometer 13.

[0080] In one embodiment, as Figure 9 shown, the direction of the optical axis spacing connection line is the y - direction in the figure, or it can be other corresponding directions of the optical axis spacing connection line.

[0081] In one embodiment, when moving the detection module 17 vertically in the x - direction until the first beam to be detected 56 is imaged on the camera 42, it may not be imaged at the center point of the camera 42. However, this will increase the complexity of calculating the imaging positions of the first beam to be detected 56 and the second beam to be detected 57 on the camera 42, and it is more likely to generate calculation errors.

[0082] Specifically, the designed optical axis spacing is the optical axis spacing between the first beam to be detected 56 set by the multi - axis interferometer 13 and the second beam to be detected 57 for comparison, and it is a fixed ideal parameter value.

[0083] Specifically, asFigure 9 As shown, since the detection module 17 moves the same optical axis design spacing E perpendicular to the x-direction at both the proximal position and the distal position, the imaging positions of the first beam to be detected 56 and the second beam to be detected 57 on the camera 42 are used to determine whether the first beam to be detected 56 and the second beam to be detected 57 can still maintain the optical axis design value when exiting the multi-axis interferometer 13 while moving away from the multi-axis interferometer 13. At the same time, since only judging the proximal position may not show a visible distance due to the small angle between the first beam to be detected 56 and the second beam to be detected 57, resulting in a misjudgment as parallel, the present invention sets the proximal position and the distal position to compare the imaging position differences, so as to further improve the detection accuracy of the beam parallelism, thereby improving the measurement accuracy of the multi-axis interferometer 13.

[0084] In one embodiment, as Figure 9 shown, the method for calculating the angle θ between the first beam to be detected 56 and one corresponding second beam to be detected 57 is as follows: The calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module 17, and calculates the angle between the second beam to be detected 57 and the first beam to be detected 56 according to A1 and A2 , where B is the pixel size of the camera 42 in the detection module 17, L1 is the distance between the imaging position of the detection module 17 in the proximal position area 15 and the exit hole of the multi-axis interferometer 13, and L2 is the distance between the imaging position of the detection module 17 in the distal position area 16 and the exit hole of the multi-axis interferometer 13. Specifically, the calculation principle is as follows: As Figure 9As shown, after the first light beam 56 to be detected is translated perpendicularly to the x direction by an optical axis design spacing E, a straight line l is obtained. The imaging center point O of the first light beam 56 to be detected is the camera 42 in the near-end position area 15. The point P reached after the point O is translated perpendicularly to the x direction by an optical axis design spacing is the position of the imaging center point of the camera 42 after the detection module 17 is translated. At this time, the imaging position of the second light beam 57 to be detected is the camera 42 in the near-end position area 15. The imaging distance between the points P and P1 is A1, and the actual distance between the points P and P1 is the product A1B of A1 and the pixel B of the camera 42. Similarly, the imaging center point M of the first light beam 56 to be detected is obtained in the far-end position area 16. The point M is translated perpendicularly to the x direction by an optical axis design spacing. Point N reached after distance E is the position of the imaging center point of the corresponding camera 42 after the detection module 17 is translated. At this time, the imaging position of the second light beam 57 to be detected in the far-end position area 16 of the camera 42 is point N1, the imaging distance between point N and point N1 is A2, and the actual distance between point N and point N1 is the product A2B of A2 and the pixel B of the camera 42; an end line i is made from point P1 along the direction parallel to the first light beam 56 to be detected, and the end line i intersects with NN1 at point Q to obtain a triangle P1QN1. From the figure, it can be seen that the distance corresponding to (A2-A1)×B, the angle θ between the first light beam 56 to be detected and the second light beam 57 to be detected, and the spacing L2-L1 between the near-end position area 15 and the far-end position area 16 can be obtained by using the tangent angle relationship in the triangle. .

[0085] In one embodiment, Figure 10 As shown, since L2 is much larger than L1, when the accuracy requirement is low, L2-L1≈L2 can be approximated as .

[0086] In one embodiment, the method of adjusting the mirror angle of the camera 42 in the detection module 17 includes: like Figure 5 and Figure 7 As shown, the detection module 17 is detachably mounted with a fixed reflection module 18, the reflection module 18 includes a camera mirror bracket 46 and a reflection mirror 45, the camera mirror bracket 46 is mounted on the mirror surface of the camera 42 of the detection module 17, and the reflection mirror 45 is located on the camera mirror bracket 46 so that the reflection mirror 45 is parallel to the mirror surface of the camera 42; like Figure 11As shown, the detection module 17 is moved from the first position in the distal position area 16 or the proximal position area 15 to the second position perpendicular to the first beam to be detected 56. The distance between the first position and the second position is fixed. The mirror 45 fixedly installed with the detection module 17 can receive the first beam to be detected 56 at both the first position and the second position, and the first reflected beam 451 and the second reflected beam 452 after the first beam to be detected 56 is reflected by the mirror 45 at the first position and the second position can both be received by the multi-axis interferometer 13. The multi-axis interferometer 13 receives the first reflected beam 451 reflected back by the first beam to be detected 56 from the first position and the second reflected beam 452 reflected back by the first beam to be detected 56 from the second position, and measures the reflection displacement ΔC between the first reflected beam 451 and the second reflected beam 452 received by the multi-axis interferometer 13. Rotate the mirror surface angle of the camera 42 installed in parallel with the mirror 45 until the obtained reflection displacement is minimized, and determine that the mirror surface of the camera 42 is perpendicular to the first beam to be detected 56 at this time, and fix the angular position of the mirror surface of the camera 42 at this time. After the adjustment of the camera 42 is completed, the reflection module 18 is removed.

[0087] In the present invention, the reflection module 18 is installed to fix the mirror 45 and the mirror surface of the camera 42 in parallel. The beam emitted by the multi-axis interferometer 13 is reflected by the mirror 45 and then received by the multi-axis interferometer 13. By using the effect that the light reflected by the mirror surface of the camera 42 that is not perpendicular to the first beam to be detected 56 is offset after being translated perpendicular to the first beam to be detected 56, the included angle between the mirror surface of the camera 42 and the direction perpendicular to the first beam to be detected 56 is amplified, so that the mirror surface of the camera 42 can be accurately adjusted to be perpendicular to the first beam to be detected 56, reducing the deviation of the detection result caused by the slope error of the mirror surface of the camera 42, so that the imaging information measured by the mirror surface of the camera 42 can more accurately reflect the parallelism between the beams.

[0088] As Figure 12 shown, the left figure is the reflection path when the mirror surface of the mirror 45 is perpendicular to the x direction. It can be seen that when the mirror surface of the mirror 45 moves from C1 perpendicular to the x direction to C2, there will be no reflection displacement ΔC, and the reflection displacement ΔC is always 0. The right figure is the reflection path when there is a slope error between the mirror surface of the mirror 45 and the direction perpendicular to the x direction. It can be seen that when the mirror surface of the mirror 45 moves from C1 perpendicular to the x direction to C2 (the translation distance is the same as G in the left figure), a reflection displacement ΔC will be generated, and the smaller the slope between the mirror surface of the mirror 45 and the direction perpendicular to the x direction, the closer the reflection displacement ΔC is to 0.

[0089] In one embodiment, the reflection module 18 is moved with the detection module 17 to a position where the distance from the multi-axis interferometer 13 is less than 100 mm for adjusting the angle of the mirror surface of the camera 42 within the proximal position area 15, and the reflection module 18 is moved with the detection module 17 to a position where the distance from the multi-axis interferometer 13 is greater than 5000 mm for adjusting the angle of the mirror surface of the camera 42 within the distal position area 16.

[0090] Specifically, the distance between the reflection module 18 and the multi-axis interferometer 13 is not a fixed value and needs to be arranged according to the measurement results so that the multi-axis interferometer 13 can obtain the reflected light beam of the mirror 45.

[0091] In one embodiment, the reflection module 18 is first set in the distal position area 16 to minimize the reflected displacement measured by the multi-axis interferometer 13; then the reflection module 18 is set in the proximal position area 15 to make the reflected displacement obtained by the multi-axis interferometer 13 as close to 0 as possible, so as to eliminate the slopes of the mirror surface of the camera 42 in the proximal position area 15 and the distal position area 16. Embodiment 2

[0092] This embodiment provides a multi-axis interferometer 13 parallelism detection system. Other features of the multi-axis interferometer 13 parallelism detection system are basically the same as those in Embodiment 1, and the differences are as follows: In this embodiment, as Figure 13 shown, the multi-axis interferometer 13 includes n exit holes; The detection system further includes a beam convergence tooling. As Figure 14 shown, the beam convergence tooling includes a convergence tooling plate 71 and n - 1 rhomboid prisms. The convergence tooling plate 71 includes n light passing holes, and the positions of the n light passing holes correspond to those of the n exit holes one by one. The n - 1 rhomboid prisms are respectively fixed on the side of the n - 1 light passing holes away from the multi-axis interferometer 13; As Figure 15 shown, the n light beams emitted by the multi-axis interferometer 13 can respectively pass through the corresponding light passing holes from the n exit holes; the first beam to be detected 56 is incident on the detection module 17 after passing through the corresponding light passing hole, and the n - 1 second beams to be detected 57, 58 ( Figure 15 shown as 2 in

[0093] are respectively incident on the detection module 17 after passing through the corresponding light passing holes and rhomboid prisms. Figure 13 In one embodiment, as Figure 14 shown, the multi-axis interferometer 13 has 3 exit holes 30, 31, 32 emitting the beams to be detected; asFigure 15 As shown, after the second beams to be detected 57 and 58 emitted from the emission holes 31 and 32 respectively pass through the light-passing holes 75 and 76 on the beam-converging tooling plate 71, they pass through the rhombic prisms 72 and 73 respectively and then are converged onto the detection module 17 for imaging; while the first beam to be detected 56 emitted from the emission hole 30 directly enters the detection module 17 for imaging after passing through the light-passing hole 74 on the beam-converging tooling plate 71, so that the three beams are all converged onto the detection module 17 at the same position for imaging.

[0094] In the present invention, the second beam to be detected 57 is offset by the rhombic prism, so that the second beam to be detected 57 is converged onto the detection module 17. Without moving the detection module 17, the imaging information of the first beam to be detected 56 and the second beam to be detected 57 can be measured. At the same time, since the rhombic prism can achieve the translation effect with the beam angle unchanged, the detection module 17 can still obtain the accurate parallelism between the first beam to be detected 56 and the second beam to be detected 57.

[0095] Specifically, as Figure 14 shown, the positions of the emission holes of the beam-converging tooling are consistent with the positions of the emission holes of the multi-axis interferometer 13.

[0096] This embodiment also provides a method for detecting the parallelism of the multi-axis interferometer 13. The detection method uses the above multi-axis interferometer 13 detection system to detect the parallelism of the multi-axis interferometer 13. Other features of the detection method are basically the same as those of Embodiment 1, and the difference lies in: In this embodiment, as Figure 15 shown, the method for the detection module 17 to receive the imaging information at the proximal end includes: When the beam-converging tooling moves the n-1 second beams to be detected 57 emitted from the multi-axis interferometer 13 to the preset imaging position within the proximal position area 15 where the detection module 17 is fixed, the detection module 17 can simultaneously image at least one of the n-1 second beams to be detected 57 and the 1 first beam to be detected 56; Fix the detection module 17 at the preset imaging position within the proximal position area 15, and the detection module 17 receives and measures the proximal imaging information as the distance A1 between the imaging center position coordinates of the first beam to be detected 56 and the corresponding 1 second beam to be detected 57; The method for the detection module 17 to receive the imaging information at the distal end includes: When the beam-converging tooling moves the n-1 second beams to be detected 57 emitted from the multi-axis interferometer 13 to the preset imaging position within the distal position area 16 where the detection module 17 is fixed, the detection module 17 can simultaneously image at least one of the n-1 second beams to be detected 57 and the 1 first beam to be detected 56; Fix the detection module 17 at a preset imaging position within the distal position area 16. The detection module 17 receives and measures the distal imaging information, which is the distance A2 between the imaging center position coordinates of the first beam to be detected 56 and the corresponding imaging center position coordinates of one second beam to be detected 57. Calculate whether A1 is equal to A2. If A1 is equal to A2, it is determined that the first beam to be detected 56 and the corresponding one second beam to be detected 57 are parallel; if A1 is not equal to A2, calculate the included angle θ between the first beam to be detected 56 and the corresponding one second beam to be detected 57, and perform angle compensation according to the calculated included angle θ corresponding to the exit angle of the second beam to be detected 57.

[0097] In the present invention, by arranging the rhombic prism in the beam convergence tooling, the n - 1 second beams to be detected 57 emitted by the multi - axis interferometer 13 can all be imaged with the first beam to be detected 56 at the same position where the detection module 17 is located. Thus, it is possible to directly calculate the imaging distance of the first beam to be detected 56 and any beam to be detected on the detection module 17 at the preset imaging position without having to move the detection module 17 perpendicular to the x - direction, reducing the required movement operations, improving the detection efficiency, and at the same time reducing the errors brought during the movement process, and further improving the accuracy of the detection results.

[0098] Specifically, as Figure 16 shown, due to the use of the beam convergence tooling, the optical axis spacing e between the first beam to be detected 56 and each second beam to be detected 57 after passing through the beam convergence tooling is greatly reduced, so that when in the proximal position area 15 or the distal position area 16, the detection module 17 can directly measure the imaging distance between the first beam to be detected 56 and the second beam to be detected 57 in the camera 42 as A2 - A1 at the same position, without having to move a distance of the optical axis design spacing E to obtain the imaging information of the first beam to be detected 56 and the second beam to be detected 57.

[0099] In summary, the multi - axis interferometer parallelism detection system and detection method of the present invention can accurately measure the beam parallelism of the multi - axis interferometer by comparing the imaging information of the proximal and distal detection modules, with high measurement accuracy, strong repeatability, and strong effectiveness of the measurement results; at the same time, by correspondingly setting the reflection modules at the distal and proximal ends to adjust the perpendicular relationship between the camera mirror surface and the optical axis of the first beam to be detected, the accuracy and repeatability of the beam parallelism measurement are further ensured; in addition, by using the beam convergence tooling to converge the beams of the multi - axis interferometer in a smaller area, the camera can image the two beams to be detected without moving, improving the detection convenience; finally, by adjusting the collimation effect of the beam shaping module through the imaging beam radii of the proximal and distal detection modules, the detection accuracy of the beam parallelism of the multi - axis interferometer is further improved.

[0100] Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0101] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A multi-axis interferometer parallelism detection system, characterized in that, The detection system includes: a light source module (11), a beam shaping module (12), a multi-axis interferometer (13), a detection module (17), and a calculation module; The laser beam (51) emitted by the light source module (11) is shaped into a collimated single-polarized incident light (55) by the beam shaping module (12). The incident light (55) enters the multi-axis interferometer (13) and is divided into n beams, including 1 first beam to be detected (56) and n - 1 second beams to be detected (57), where n is an integer greater than or equal to 2. A preset x direction is defined, and the optical axis of the first beam to be detected (56) is parallel to the x direction; The detection module (17) is configured to receive and measure the proximal imaging information and the distal imaging information of the first beam to be detected (56) and the second beams to be detected (57) on the imaging plane perpendicular to the x direction in the proximal position area (15) and the distal position area (16). The distance between the distal position area (16) and the multi-axis interferometer (13) along the x direction is greater than the distance between the proximal position area (15) and the multi-axis interferometer (13) along the x direction; The calculation module is connected to the detection module (17) and is configured to obtain the parallelism between the second beam to be detected (57) and the first beam to be detected (56) based on the proximal imaging information and the distal imaging information.

2. The multi-axis interferometer parallelism detection system according to claim 1, wherein, The detection system further includes a displacement device. The detection module (17) is located on the displacement device, and the displacement device is configured to drive the detection module (17) to move between the distal position area (16) and the proximal position area (15), and / or the displacement device is configured to drive the detection module (17) to move within the distal position area (16) or within the proximal position area (15).

3. The multi-axis interferometer parallelism detection system according to claim 1, wherein The multi-axis interferometer (13) includes n exit holes (30); The multi-axis interferometer parallelism detection system further includes a beam convergence tooling, which includes a convergence tooling plate (71) and n - 1 rhombic prisms (72). The convergence tooling plate (71) includes n light-passing holes (74), and the positions of the n light-passing holes (74) correspond one-to-one to the positions of the n exit holes (30). The n - 1 rhombic prisms (72) are respectively fixed on the side of the n - 1 light-passing holes (74) away from the multi-axis interferometer (13); The n beams emitted by the multi-axis interferometer (13) can respectively pass through the corresponding light-passing holes (74) from the n exit holes (30). The first beam to be detected (56) enters the detection module (17) after passing through the corresponding light-passing hole (74), and the n - 1 second beams to be detected (57) enter the detection module (17) after passing through the corresponding light-passing holes (74) and the rhombic prisms (72) respectively; 4. The multi-axis interferometer parallelism detection system according to claim 1, wherein The beam shaping module (12) includes a linear polarizer (21), a converging lens (22), an exit hole (23), and a collimating lens (24) arranged in sequence along the x direction; The laser beam (51) emitted by the light source module is incident on the linear polarizer (21) and adjusted to a single-polarized light (52). The single-polarized light (52) is converged into a converging beam (53) after passing through the converging lens (22). The converging beam (53) emits a collimated beam (54) from the light-emitting hole (23) and is collimated after passing through the collimating lens (24) to obtain a collimated single-polarized incident light (55).

5. The multi-axis interferometer parallelism detection system according to claim 4, wherein The collimating lens (24) has the same parameters as the converging lens (22). The focal length of the converging lens (22) is f, the aperture of the light exit hole (23) is D1, and the beam diameter of the laser beam (51) incident on the beam shaping module (12) is D2, and .

6. The multi-axis interferometer parallelism detection system according to claim 1, wherein The detection module (17) includes a positioning hole (41) and a camera (42). The positioning hole (41) is used to image the beam incident on the camera (42) in the central area of the camera (42).

7. The multi-axis interferometer parallelism detection system according to claim 6, wherein, The multi-axis interferometer parallelism detection system further includes a reflection module (18). The reflection module (18) includes a camera mirror bracket (46) detachably mounted on the mirror surface of the camera (42) of the detection module (17) and a reflector (45). The reflector (45) is mounted on the side of the camera mirror bracket (46) away from the camera (42). The first beam to be detected (56) can be reflected by the reflector (45) to the multi-axis interferometer (13).

8. A method for detecting the parallelism of a multi-axis interferometer, characterized in that, The detection method uses the multi-axis interferometer (13) detection system according to any one of claims 1-7 to detect the parallelism of the multi-axis interferometer. The detection method includes: The light source module (11) emits a laser beam (51). The laser beam (51) is shaped into a collimated single-polarized incident light (55) after passing through the beam shaping module (12). The incident light (55) is divided into one first beam to be detected (56) and n-1 second beams to be detected (57) after passing through the multi-axis interferometer (13), where n is an integer greater than or equal to 2; Adjust the mirror angle of the camera (42) in the detection module (17) so that the mirror surfaces of the camera (42) are all perpendicular to the first beam to be detected (56); The detection module (17) receives and measures the proximal imaging information of the first beam to be detected (56) and each second beam to be detected (57) on the imaging surface perpendicular to the first beam to be detected (56) in the proximal position area (15); the detection module (17) receives and measures the distal imaging information of the first beam to be detected (56) and each second beam to be detected (57) on the imaging surface perpendicular to the first beam to be detected (56) in the distal position area (16); The calculation module determines the parallelism between each second beam to be detected (57) and the first beam to be detected (56) according to the proximal imaging information and the distal imaging information; when it is determined that there is a second beam to be detected (57) that is not parallel to the first beam to be detected (56), calculate the angle θ between the second beam to be detected (57) and the first beam to be detected (56), and perform angle compensation on the emission angle of the second beam to be detected (57) according to the calculated angle θ.

9. The parallelism detection method of the multi-axis interferometer according to claim 8, characterized in that The method for the detection module (17) to receive and measure the proximal imaging information includes: When moving n - 1 of the second beams to be detected (57) emitted from the multi - axis interferometer (13) to a preset imaging position within the proximal position area (15) where the detection module (17) is fixed by using a beam - converging tooling, the detection module (17) can simultaneously image at least one of the second beams to be detected (57) among one first beam to be detected (56) and n - 1 second beams to be detected (57). Fix the detection module (17) at the preset imaging position within the proximal position area (15). The detection module (17) receives and measures the proximal imaging information, which is the distance A1 between the imaging center position coordinates of the first beam to be detected (56) and one corresponding second beam to be detected (57). The method for the detection module (17) to receive and measure the distal imaging information includes: When moving n - 1 of the second beams to be detected (57) emitted from the multi - axis interferometer (13) to a preset imaging position within the distal position area (16) where the detection module (17) is fixed by using a beam - converging tooling, the detection module (17) can simultaneously image at least one of the second beams to be detected (57) among one first beam to be detected (56) and n - 1 second beams to be detected (57). Fix the detection module (17) at the preset imaging position within the distal position area (16). The detection module (17) receives and measures the distal imaging information, which is the distance A2 between the imaging center position coordinates of the first beam to be detected (56) and one corresponding second beam to be detected (57). Calculate whether A1 is equal to A2. If A1 is equal to A2, it is determined that the first beam to be detected (56) and one corresponding second beam to be detected (57) are parallel. If A1 is not equal to A2, calculate the included angle θ between the first beam to be detected (56) and one corresponding second beam to be detected (57), and perform angle compensation according to the calculated included angle θ corresponding to the emission angle of the second beam to be detected (57).

10. The parallelism detection method of the multi-axis interferometer according to claim 8, characterized in that, The method for the detection module (17) to receive and measure the proximal imaging information includes: After moving the detection module (17) vertically in the x - direction within the proximal position area (15) until the first beam to be detected (56) is imaged at the center point of the camera, the detection module (17) moves a preset distance vertically in the x - direction with this position as the center position and then receives and measures the proximal imaging information, which is the distance A1 between the imaging coordinate of one of the n - 1 second beams to be detected (57) in the camera and the center point. The preset distance is the designed optical axis spacing between the first beam to be detected (56) and this second beam to be detected (57). The method for the detection module (17) to receive and measure the distal imaging information includes: The detection module (17) is moved vertically in the remote position area (16) in the direction perpendicular to the x-axis until the first beam to be detected (56) forms an image at the center point of the camera. After that, with this position as the central position, the detection module (17) is moved in the direction perpendicular to the x-axis by the designed spacing of the optical axis, and then the remote imaging information is received and measured. The distance A2 between the imaging coordinate of one of the n - 1 second beams to be detected (57) and the center point in the camera is obtained. Calculate whether A1 is equal to A2. If A1 is equal to A2, it is determined that the first beam to be detected (56) is parallel to the corresponding one of the second beams to be detected (57). If A1 is not equal to A2, calculate the included angle θ between the first beam to be detected (56) and the corresponding one of the second beams to be detected (57), and perform angle compensation on the emission angle of the second beam to be detected (57) according to the calculated included angle θ.

11. The multi-axis interferometer parallelism detection method according to claim 9 or 10, characterized in that, The method for calculating the angle θ between the first beam to be detected (56) and one corresponding second beam to be detected (57) is as follows: The calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module (17), and calculates the angle between the second beam to be detected (57) and the first beam to be detected (56) according to A1 and A2. , where B is the pixel size of the camera in the detection module (17), L1 is the distance between the imaging position of the detection module (17) in the proximal position area (15) and the exit hole (30) of the multi-axis interferometer (13), and L2 is the distance between the imaging position of the detection module (17) in the distal position area (16) and the exit hole (30) of the multi-axis interferometer (13).

12. The multi-axis interferometer parallelism detection method according to any one of claims 8-10, characterized in that, The method for adjusting the mirror angle of the camera (42) in the detection module (17) includes: A reflection module (18) is detachably and fixedly installed on the detection module (17). The reflection module (18) includes a camera mirror bracket (46) and a reflector (45). The camera mirror bracket (46) is installed on the mirror surface of the camera (42) of the detection module (17), and the reflector (45) is located on the camera mirror bracket (46) so that the reflector (45) is parallel to the mirror surface of the camera (42). The detection module (17) is moved from the first position in the remote position area (16) or the proximal position area (15) to the second position perpendicular to the first beam to be detected (56). The distance between the first position and the second position is fixed. The reflector (45) fixedly installed with the detection module (17) can receive the first beam to be detected (56) at both the first position and the second position, and the first reflected beam (451) and the second reflected beam (452) after the first beam to be detected (56) is reflected by the reflector (45) at the first position and the second position can both be received by the multi-axis interferometer (13). The multi-axis interferometer (13) receives the first reflected beam (451) reflected back from the first position of the first beam to be detected (56) and the second reflected beam (452) reflected back from the second position of the first beam to be detected (56), and measures the reflection displacement between the first reflected beam (451) and the second reflected beam (452) received by the multi-axis interferometer (13). Rotate the mirror angle of the camera (42) installed in parallel with the reflector (45) until the obtained reflection displacement is the smallest, and determine that the mirror surface of the camera (42) is perpendicular to the first beam to be detected (56) at this time, and fix the angular position of the mirror surface of the camera (42) at this time. After the adjustment of the camera (42) is completed, the reflection module (18) is removed.

Images