Optical path combining system

Abstract

The application discloses an optical path beam combining system and belongs to the technical field of optical path beam combining. The optical path beam combining system comprises a 635nm light source module, a 1550nm light source module, a first collimating lens, a collimating filter module, a beam combining and splitting turning module, a corner cube prism and a light detection module. Through the precise design of the double aspheric collimating lens, the divergence angle of the 635nm light beam is less than or equal to 0.002 mrad after collimation, and the divergence angle of the 1550nm light beam is less than or equal to 0.001 mrad. Within the range of 0-20 meters, the diameter change rate of the 1550nm light beam spot is less than or equal to 0.4%, and the diameter change rate of the 635nm light beam spot is less than or equal to 5%. The core problem that the spot size increases with the distance in the prior art is solved, and the requirement of long-distance beam combining is met.

Description

Technical Field

[0001] This invention relates to the field of optical beam combining technology, and more specifically, to an optical beam combining system. Background Technology

[0002] In fields such as optical communication and long-distance measurement, the application of optical beam combining technology is crucial. Its core requirement is to achieve efficient beam combining of multi-band beams and ensure the stability of the beams during long-distance transmission.

[0003] Current beam combiners on the market have significant limitations in beam combining distance. Most existing products can only meet the requirements of short-distance beam combining within a few meters, and cannot adapt to the needs of long-distance applications exceeding 20 meters. The beam transmission stability is poor over long distances, and the beam aperture increases significantly with the transmission distance. Typically, the beam diameter increases by more than 5% for every 10-meter increase in distance, resulting in a significant decrease in beam combining accuracy. Furthermore, stray light and ghosting interference are severe. Due to the lack of targeted band filtering and optical path optimization design, interference and scattering are prone to occur during beam combining. The intensity of stray light often exceeds 5% of the main beam intensity, and the ghosting phenomenon is prominent, directly affecting the purity of signal transmission and the accuracy of measurement results.

[0004] To address this, an optical path beam combining system is proposed. Summary of the Invention

[0005] The technical objective of this invention is to provide an optical path beam combining system to address the above-mentioned shortcomings and solve the problems mentioned above.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The optical beam combining system includes a 635nm light source module, a 1550nm light source module, a first collimating lens, a collimating filter module, a beam combining, splitting, and steering module, a cornerstone prism, and a light detection module, wherein:

[0008] The output end of the 635nm light source module is connected to the first collimating lens, and the output end of the first collimating lens is connected to the beam combining, splitting and steering module.

[0009] The beam emitted by the 635nm light source module is collimated by the first collimating lens and then incident on the corner prism through the beam combining, splitting and turning module.

[0010] The beam emitted by the 1550nm light source module is collimated and filtered by the collimation and filtering module, and then combined with the beam emitted by the 635nm light source module by the beam combining and splitting and turning module before being emitted to the corner prism. The combined beam spot is reflected by the corner prism and then passes through the beam combining and splitting and turning module so that the beam emitted by the 635nm light source module reaches the photodetector module.

[0011] The collimating filter module includes a second collimating lens connected to the output end of the 1550nm light source module. The output end of the second collimating lens is connected to a first filter. Both the first collimating lens and the first filter are connected to a corner prism through a beam combining and splitting steering module. The beam combining and splitting steering module is connected to a light detection module.

[0012] Both the first collimating lens and the second collimating lens are aspherical lenses;

[0013] The beam splitter in the beam combining, splitting and steering module is adapted to the beam combining and splitting requirements of 635nm and 1550nm dual-band beams. It can ensure the effective transmission of the target band beam with a transmission or reflection ratio of ≥70%, and at the same time realize the directional splitting of the dual-band beams to avoid cross interference.

[0014] Preferably, the beam combining, splitting, and steering module includes a first reflecting mirror, a first beam splitter, a second beam splitter, and a second reflecting mirror; the output end of the first collimating lens is connected to the incident end of the first reflecting mirror, the output end of the first reflecting mirror is connected to the incident end of the first beam splitter, and the output end of the first filter is also connected to the incident end of the first beam splitter; the output end of the first beam splitter is connected to the second beam splitter, one path of the second beam splitter is connected to a corner bevel prism, and the other path is connected to the second reflecting mirror; the output end of the second reflecting mirror is connected to a light detection module.

[0015] Preferably, the light detection module includes a second filter connected to the output end of the second reflector, and the output end of the second filter is sequentially connected to a focusing lens and a PSD detection module.

[0016] Preferably, both the first collimating lens and the second collimating lens are made of N-SF6. The first collimating lens has a lens diameter of 25mm, a center thickness of 9.8mm, an effective focal length of 25mm, a light-transmitting aperture of 22.5mm, and an edge thickness of 5.9mm. The second collimating lens has a lens diameter of 25mm, a center thickness of 8.3mm, an effective focal length of 25mm, a light-transmitting aperture of 22.5mm, and an edge thickness of 4.4mm.

[0017] Preferably, the surface profile parameters of the first collimating lens are: K=-0.872, A4=3.148E-06, A6=-1.842E-09, A8=-3.342E-12; and the surface profile parameters of the second collimating lens are: K=-1, A4=6.493E-06, A6=-7.475E-10, A8=-4.679E-12. The surface profile errors of both the first and second collimating lenses are 0.4λRMS, and both are coated with anti-reflective coatings with a transmittance T>99.7%.

[0018] Preferably, the first and second reflectors have a reflectivity of ≥99% for 635nm wavelength beams and a flatness error of ≤0.1λRMS for the reflective surface.

[0019] Preferably, both the first and second beam splitters are N-BK7 cemented cubic prisms with a side length of 25.4 mm, and the beam splitting ratio for 635 nm and 1550 nm beams is 1:9 (reflectivity:transmittance).

[0020] Preferably, the first filter is a 1550nm narrowband pass filter with a center wavelength of 1550±2nm, a half-width of 10nm, a peak transmittance of ≥90%, and a cutoff rate of ≥OD4 for 635nm beams; the second filter is a 635nm narrowband pass filter with a center wavelength of 635±2nm, a half-width of 10nm, a peak transmittance of ≥90%, and a cutoff rate of ≥OD4 for 1550nm beams.

[0021] Preferably, the cornerstone prism is fixed to a two-dimensional displacement platform, which is mounted on a triangular bracket; the cornerstone prism is driven by manually tightening the drive rod to achieve longitudinal movement of 0-20 meters, and by tightening the displacement platform nut to achieve lateral movement, with a repeatability of 0.01 mm.

[0022] Preferably, the effective detection area of ​​the PSD detection module is 10mm×10mm, its response wavelength range is 320-1100nm, its detection depth is 3.05mm, and its resolution is 0.75μm; the focal length of the focusing lens is 25mm, and its distance from the detection surface of the PSD detection module is 25mm.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0024] 1. This invention, through the precise design of dual aspherical collimating lenses, achieves a divergence angle of ≤0.002mrad for the 635nm beam after collimation and ≤0.001mrad for the 1550nm beam. Within a round trip range of 0-20 meters (40 meters), the change rate of the 1550nm beam spot diameter is ≤0.4%, and the change rate of the 635nm beam spot diameter is ≤5%, completely solving the core problem of spot diameter expansion with distance in existing technologies and meeting the requirements for long-distance beam combining.

[0025] 2. This invention, through the synergistic effect of the pre-filtering of the collimation filter module and the secondary filtering of the light detection module, combined with a high-reflectivity mirror and a beam splitter with a specific beam splitting ratio, ensures that the stray light intensity within 9mm of the center diameter of the PSD detection module accounts for ≤1% of the 635nm main beam intensity, and there are no obvious identifiable ghost images, thus significantly improving beam purity. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a diagram of the optical transmission path according to an embodiment of the present invention.

[0028] In the diagram: 100nm and 635nm light source modules;

[0029] 200nm and 1550nm light source modules;

[0030] 300. First collimating lens;

[0031] 400. Collimating filter module; 410. Second collimating lens; 420. First filter;

[0032] 500. Beam combining, splitting, and steering module; 510. First reflecting mirror; 520. First beam splitter; 530. Second beam splitter; 540. Second reflecting mirror;

[0033] 600. Cornerstone prism;

[0034] 700, Light detection module; 710, Second filter; 720, Focusing lens; 730, PSD detection module. Detailed Implementation

[0035] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 1As shown, the optical beam combining system according to an embodiment of the present invention includes a 635nm light source module 100, a 1550nm light source module 200, a first collimating lens 300, a collimating filter module 400, a beam combining / splitting and steering module 500, a cornerstone prism 600, and a light detection module 700. The output end of the 635nm light source module 100 is connected to the first collimating lens 300, and the output end of the first collimating lens 300 is connected to the beam combining / splitting and steering module 500. The light beam emitted from the 635nm light source module 100 is collimated by the first collimating lens 300 and then incident on the cornerstone prism 600 after passing through the beam combining / splitting and steering module 500. The light beam emitted from the 1550nm light source module 200 is collimated and filtered by the collimating filter module 400, and then combined with the light beam emitted from the 635nm light source module 100 by the beam combining / splitting and steering module 500 before exiting onto the cornerstone prism 600. The combined light spot passes through the cornerstone prism. After reflection at 600 nm, the beam emitted by the 635 nm light source module 100 is directed to the photodetector module 700 via the beam combining and splitting steering module 500. The collimating filter module 400 includes a second collimating lens 410 connected to the output of the 1550 nm light source module 200. The output of the second collimating lens 410 is connected to a first filter 420. Both the first collimating lens 300 and the first filter 420 are connected to a corner bevel prism 600 via the beam combining and splitting steering module 500. The beam combining and splitting steering module 500 is connected to the photodetector module 700. The beam combining and splitting steering module 500 and the photodetector module 700 are physically connected via a second reflecting mirror 540 inside the module: the output of the second reflecting mirror 540 is directly connected to the input of the photodetector module 700, specifically, the light outlet of the second reflecting mirror 540 is aligned with the light inlet of the second filter 710 in the photodetector module, forming a continuous optical path (see attached diagram). Figure 1 (Connection relationship between the second reflecting mirror 540 and the second filter 710); both the first collimating lens 300 and the second collimating lens 410 are aspherical lenses; the divergence angle of the 635nm beam after collimation is ≤0.002mrad, and the divergence angle of the 1550nm beam after collimation is ≤0.001mrad; the coaxiality error of the two beams after beam combining is ≤30um; the divergence angles of ≤0.002mrad (635nm) and ≤0.001mrad (1550nm) directly ensure the stability of the long-distance beam spot, and the coaxiality error of ≤30um ensures the beam combining accuracy of the dual-band beams and improves the overall performance of the system; the beam spot diameter change rate of the 1550nm beam in the round trip range of 0-20 meters is ≤0.4%; the change rate of ≤0.4% highlights the superiority of long-distance beam combining in this band and meets the requirements of application scenarios with extremely high requirements for beam spot stability (such as long-distance optical communication).

[0039] Example 2

[0040] like Figure 1As shown, the optical path beam combining system provided in this embodiment differs from that in Embodiment 1 in that:

[0041] The beam combining, splitting, and steering module 500 includes a first reflecting mirror 510, a first beam splitter 520, a second beam splitter 530, and a second reflecting mirror 540. The output end of the first collimating lens 300 is connected to the incident end of the first reflecting mirror 510, and the output end of the first reflecting mirror 510 is connected to the incident end of the first beam splitter 520. The output end of the first filter 420 is also connected to the incident end of the first beam splitter 520. The output end of the first beam splitter 520 is connected to the second beam splitter 530. One path of the second beam splitter 530 is connected to the corner prism 600, and the other path is connected to the second reflecting mirror 540. The output end of the second reflecting mirror 540 is connected to the photodetector module 700. Through the synergistic effect of the first reflecting mirror 510, the first beam splitter 520, the second beam splitter 530, and the second reflecting mirror 540, the beam transmission direction is precisely controlled, achieving interference-free beam combining of dual-band beams and directional beam splitting of reflected beams, ensuring beam coaxiality and optical path stability.

[0042] The optical detection module 700 includes a second filter 710 connected to the output end of the second reflector 540. The output end of the second filter 710 is sequentially connected to a focusing lens 720 and a PSD detection module 730. Through the secondary stray light filtering of the second filter 710, the precise focusing of the focusing lens 720, and the high-precision detection of the PSD detection module 730, the pure reception and position identification of the 635nm reflected beam are achieved, thereby improving the detection accuracy and anti-interference capability.

[0043] Both the first collimating lens 300 and the second collimating lens 410 are made of N-SF6. The first collimating lens 300 has a lens diameter of 25mm, a center thickness of 9.8mm, an effective focal length of 25mm, a light-transmitting aperture of 22.5mm, and an edge thickness of 5.9mm. The second collimating lens 410 has a lens diameter of 25mm, a center thickness of 8.3mm, an effective focal length of 25mm, a light-transmitting aperture of 22.5mm, and an edge thickness of 4.4mm. The N-SF6 material is suitable for dual-band transmittance requirements, and the specific size design ensures the stability of the lens structure. Combined with the aspherical surface shape, it provides structural support for long-distance low-divergence collimation of the beam.

[0044] The surface profile parameters of the first collimating lens 300 are: K=-0.872, A4=3.148E-06, A6=-1.842E-09, A8=-3.342E-12; the surface profile parameters of the second collimating lens 410 are: K=-1, A4=6.493E-06, A6=-7.475E-10, A8=-4.679E-12. The surface profile errors of both the first collimating lens 300 and the second collimating lens 410 are 0.4λRMS, and both are coated with anti-reflection coatings with a transmittance T>99.7%. By compensating for spherical aberration through higher-order surface profile parameters, the surface profile error of 0.4λRMS and the anti-reflection coating with T>99.7% ensure that the beam divergence angle is controlled within an extremely low range, achieving stable long-distance beam spot.

[0045] The first reflector 510 and the second reflector 540 have a reflectivity of ≥99% for 635nm wavelength beams and a flatness error of ≤0.1λRMS for the reflective surface. The ≥99% reflectivity reduces beam energy loss, and the flatness error of ≤0.1λRMS avoids beam scattering, ensuring the accuracy of beam transmission direction and energy stability.

[0046] Both the first beam splitter 520 and the second beam splitter 530 are N-BK7 cemented cubic prisms with a side length of 25.4 mm. When the incident angle is 45°, the splitting ratio of the 635 nm and 1550 nm beams by the first beam splitter 520 and the second beam splitter 530 is reflectance:transmittance = 1:9. The N-BK7 cemented cubic prism ensures structural stability, and the 1:9 splitting ratio is suitable for dual-band beam combining and splitting requirements, achieving efficient beam combining and directional splitting without cross-interference. The first beam splitter 520 coaxially combines 10% of the reflected light from the 635 nm beam and 90% of the transmitted light from the 1550 nm beam, which is then incident on the second beam splitter 530.

[0047] It should be noted that the 1:9 splitting ratio described above is a preferred embodiment of the present invention and not the only limiting solution. As long as the splitting ratio of the beam splitter for the 635nm and 1550nm beams can ensure effective beam combining (transmission / reflection ratio ≥ 70%) and isolation of stray light in the target wavelength band, other reasonable splitting ratios (such as 2:8, 3:7, etc.) can achieve the technical effects of the present invention. The selection of the splitting ratio needs to be coordinated with the parameters of the filter module and the reflector. For example, when the cutoff rate of the filter module is increased, the transmission / reflection ratio of the beam splitter can be appropriately adjusted. Those skilled in the art can flexibly adjust it according to the actual application scenario (such as beam combining efficiency requirements, stray light suppression intensity requirements, etc.).

[0048] The first filter 420 is a 1550nm narrowband pass filter with a center wavelength of 1550±2nm, a half-width of 10nm, a peak transmittance ≥90%, and a cutoff rate ≥OD4 for 635nm beams; the second filter 710 is a 635nm narrowband pass filter with a center wavelength of 635±2nm, a half-width of 10nm, a peak transmittance ≥90%, and a cutoff rate ≥OD4 for 1550nm beams. Both filters precisely filter stray light from non-target wavelengths, ensuring the transmission efficiency of the target beam with a peak transmittance ≥90%, and completely suppressing stray light interference with a cutoff rate ≥OD4, thus providing dual protection for beam purity from both the source and the end.

[0049] The corner cube prism 600 is fixed to a two-dimensional displacement platform, which is mounted on a triangular bracket. The corner cube prism 600 is driven by manually turning the drive rod to achieve longitudinal movement from 0 to 20 meters, and by turning the displacement stage nut to achieve lateral movement, with a repeatability of 0.01 mm. The combined design of the two-dimensional displacement platform and the triangular bracket enables longitudinal distance adjustment from 0 to 20 meters and lateral position fine-tuning. The 0.01 mm repeatability ensures the accuracy of the incident position of the combined beam and improves the system's measurement repeatability. The drive rod is equipped with millimeter-level graduations, and the lateral displacement stage has a locking device to ensure no offset after positioning.

[0050] The PSD detection module 730 has an effective detection area of ​​10mm × 10mm, a response wavelength range of 320-1100nm, a detection depth of 3.05mm, and a resolution of 0.75μm. The focusing lens 720 has a focal length of 25mm, and its distance from the detection surface of the PSD detection module 730 is 25mm. The wide response wavelength range and high resolution of the PSD detection module 730, combined with the precise focal length design of the focusing lens and the fixed spacing of 25mm, ensure that the focused light falls accurately on the detection surface, realizing micron-level detection of the lateral position of the corner cube prism and ensuring measurement accuracy.

[0051] Within a 9mm diameter area at the center of the detection surface of the PSD detection module 730, the stray light intensity accounts for ≤1% of the intensity of the 635nm main beam, and there are no obvious identifiable ghost images. The stray light intensity ratio of ≤1% and the absence of obvious ghost images significantly improve the purity of the detection signal, avoid measurement errors caused by stray light interference, and ensure the accuracy of the detection results.

[0052] Working principle:

[0053] 635nm beam transmission path: The beam emitted by the 635nm light source module 100 first enters the first collimating lens 300. Through the precise correction of the aspherical surface shape, the beam is collimated with high precision. The collimated beam is incident on the first reflecting mirror 510. After the transmission direction is changed by reflection, it enters the first beam splitter 520 and is reflected by the first beam splitter 520 to the second beam splitter 530. Finally, it is emitted from the second beam splitter 530 to the corner cube prism 600.

[0054] 1550nm beam transmission path: The beam emitted by the 1550nm light source module 200 enters the collimating filter module 400, is first collimated by the second collimating lens 410, and then filtered by the first filter 420 to remove stray light from the non-1550nm band. The purified collimated beam is incident on the first beam splitter 520. After being transmitted through the first beam splitter 520, it is combined with the 635nm beam on the same optical axis. The combined beam is then emitted through the second beam splitter 530 to the corner cube prism 600.

[0055] Reflected beam splitting and detection path: After receiving the combined beam, the corner bevel prism 600 reflects it, and the reflected mixed beam returns to the second beam splitter 530; the 635nm beam is reflected by the second beam splitter 530 to the second reflector 540, and after being turned by the second reflector 540, it enters the second filter 710. After filtering out residual stray light, it is focused by the focusing lens 720 to the PSD detection module 730, realizing accurate detection of the lateral position of the corner bevel prism 600; the 1550nm beam is transmitted through the second beam splitter 530 and can be collected or output by the subsequent receiving device according to actual needs.

[0056] Through the above specific embodiments, those skilled in the art can easily implement the present invention. However, it should be understood that the present invention is not limited to the specific embodiments described above. Based on the disclosed embodiments, those skilled in the art can arbitrarily combine different technical features to achieve different technical solutions.

Claims

1. An optical path combining system, characterized by, The application relates to a light source module, which comprises a 635nm light source module (100), a 1550nm light source module (200), a first collimating lens (300), a collimating filter module (400), a light beam combining and splitting and turning module (500), a corner cube prism (600) and a light detection module (700), wherein: The output end of the 635nm light source module (100) is connected with the first collimating lens (300), the output end of the first collimating lens (300) is connected with the light beam combining and splitting and turning module (500); the light beam emitted by the 635nm light source module (100) is collimated by the first collimating lens (300) and then is incident to the corner cube prism (600) through the light beam combining and splitting and turning module (500); the light beam emitted by the 1550nm light source module (200) is collimated and filtered by the collimating filter module (400) and then is combined with the light beam emitted by the 635nm light source module (100) and is emitted to the corner cube prism (600) through the light beam combining and splitting and turning module (500), the combined light spot is reflected by the corner cube prism (600) and then makes the light beam emitted by the 635nm light source module (100) reach the light detection module (700) through the light beam combining and splitting and turning module (500); the beam splitter in the light beam combining and splitting and turning module (500) is adapted to the combining and splitting requirements of the 635nm and 1550nm dual-band light beams, can guarantee that the transmission or reflection proportion of the target waveband light beam is greater than or equal to 70% effective transmission, and can realize directional splitting of the dual-band light beams to avoid cross interference; The collimating filter module (400) comprises a second collimating lens (410) connected with the output end of the 1550nm light source module (200), the output end of the second collimating lens (410) is connected with a first filter (420), the first collimating lens (300) and the first filter (420) are both connected with the corner cube prism (600) through the light beam combining and splitting and turning module (500), the light beam combining and splitting and turning module (500) is connected with the light detection module (700); the first collimating lens (300) and the second collimating lens (410) are both aspherical lenses; The light beam combining, splitting and turning module (500) comprises a first mirror (510), a first beam splitter (520), a second beam splitter (530), a second mirror (540); the output end of the first collimating lens (300) is connected with the incident end of the first mirror (510), the output end of the first mirror (510) is connected with the incident end of the first beam splitter (520), and the output end of the first filter (420) is also connected with the incident end of the first beam splitter (520); the output end of the first beam splitter (520) is connected with the second beam splitter (530), the second beam splitter (530) is connected with the corner cube prism (600) in one way and the second mirror (540) in another way, and the output end of the second mirror (540) is connected with the light detection module (700); the light detection module (700) comprises a second filter (710) connected with the output end of the second mirror (540), and the output end of the second filter (710) is sequentially connected with a focusing lens (720) and a PSD detection module (730). The materials of the first collimating lens (300) and the second collimating lens (410) are N-SF6, the lens aperture of the first collimating lens (300) is 25 mm, the center thickness thereof is 9.8 mm, the effective focal length thereof is 25 mm, the light aperture thereof is 22.5 mm, and the edge thickness thereof is 5.9 mm, the lens aperture of the second collimating lens (410) is 25 mm, the center thickness thereof is 8.3 mm, the effective focal length thereof is 25 mm, the light aperture thereof is 22.5 mm, and the edge thickness thereof is 4.4 mm; the face shape parameters of the first collimating lens (300) are as follows: K=-0.872, A4=3.148E-06, A6=-1.842E-09, and A8=-3.342E-12; the face shape parameters of the second collimating lens (410) are as follows: K=-1, A4=6.493E-06, A6=-7.475E-10, and A8=-4.679E-12; the face shape errors of the first collimating lens (300) and the second collimating lens (410) are both 0.4λRMS, and the surfaces thereof are both coated with an antireflection film, and the transmittance T is greater than 99.7%; the reflectivity of the first mirror (510) and the second mirror (540) to the light beam of the 635 nm band is greater than or equal to 99%, and the flatness error of the reflecting surface is less than or equal to 0.1λRMS; the first beam splitter (520) and the second beam splitter (530) are both N-BK7 cemented cubic prisms, the side length of which is 25.4 mm, and the light splitting ratio of the first beam splitter (520) and the second beam splitter (530) to the light beams of 635 nm and 1550 nm is reflectance:transmittance=1:9; the first filter (420) is a 1550 nm narrow band filter, the center wavelength of which is 1550±2 nm, the half bandwidth of which is 10 nm, the peak transmittance of which is greater than or equal to 90%, and the cutoff rate of the first filter (420) to the light beam of 635 nm is greater than or equal to OD4; the second filter (710) is a 635 nm narrow band filter, the center wavelength of which is 635±2 nm, the half bandwidth of which is 10 nm, the peak transmittance of which is greater than or equal to 90%, and the cutoff rate of the second filter (710) to the light beam of 1550 nm is greater than or equal to OD4.

2. The optical path combining system of claim 1, wherein: The corner cube prism (600) is fixed on a two-dimensional displacement platform, and the two-dimensional displacement platform is installed on a triangular support; the driving mode of the corner cube prism (600) is to manually twist a driving rod to realize longitudinal 0-20m movement, and to twist a displacement table nut to realize transverse movement, and the repeated positioning accuracy is 0.01mm.

3. The optical path combining system of claim 1, wherein: The effective detection area of the PSD detection module (730) is 10mm*10mm, the response wavelength range is 320-1100nm, the detection depth is 3.05mm, and the resolution is 0.75μm; the focal length of the focusing lens (720) is 25mm, and the distance between the focusing lens (720) and the detection surface of the PSD detection module (730) is 25mm.

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