A large-field-of-view single-photon laser three-dimensional imaging optical system

Abstract

The invention relates to a laser imaging system, and in particular to a large-field-of-view single-photon laser three-dimensional imaging optical system. To solve the problem that the prior art is difficult to achieve miniaturization, high sensitivity, large field of view and high frame rate of laser three-dimensional imaging when mounted on an unmanned aerial vehicle, the optical system comprises a laser emitting unit and a laser receiving unit. The laser emitting unit comprises a laser, a first lens barrel arranged at one end corresponding to the laser emission end, and a first optical component arranged in the first lens barrel. The first optical component comprises a first lens, a second lens and a third lens arranged in sequence along the laser emission light path; the laser receiving unit comprises a laser receiving focal plane component, a second lens barrel and a second optical component arranged in the second lens barrel; the second optical component comprises a primary mirror, a secondary mirror, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter, an eighth lens and a ninth lens arranged in sequence along the light path.

Description

Technical Field

[0001] The invention relates to a laser imaging system, in particular to a large-field-of-view single-photon laser three-dimensional imaging optical system. Background Art

[0002] Laser 3D imaging technology uses actively emitted laser pulses to illuminate the target, and uses the echo energy reflected by the target to image the target. Unlike two-dimensional images such as visible light and infrared, the target image obtained by three-dimensional laser imaging contains the distance information of the target, which can accurately locate the target. Therefore, laser 3D imaging technology is suitable for occasions such as three-dimensional construction of digital cities and natural disaster rescue. At the same time, due to the continuous innovation of drone technology, the demand for three-dimensional imaging carried by drones has gradually increased. Its three-dimensional imaging has the characteristics of miniaturization, high sensitivity, long distance and high frame rate. At present, in order to achieve a large field of view, laser 3D imaging technology mostly scans and images the target area through two-dimensional scanning, resulting in a low imaging frame rate. Therefore, it is very necessary to develop a miniaturized and highly sensitive laser 3D imaging system that can be applied to drones to perform large field of view and high frame rate 3D imaging of distant targets. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art that it is difficult to achieve miniaturization, high sensitivity, large field of view and high frame rate laser three-dimensional imaging when mounted on an unmanned aerial vehicle, and to provide a large-field-of-view single-photon laser three-dimensional imaging optical system.

[0004] To achieve the above objectives, the technical solutions provided by the present invention are as follows:

[0005] A large-field-of-view single-photon laser three-dimensional imaging optical system comprises a laser emitting unit and a laser receiving unit, and the laser emitting unit is special in that: the laser emitting unit comprises a laser, a first lens barrel with one end corresponding to the laser emission end, and a first optical component arranged in the first lens barrel, the first optical component comprises a first lens, a second lens, and a third lens arranged in sequence along the laser emission light path; the laser receiving unit comprises a laser receiving focal plane component, a second lens barrel, and a second optical component arranged in the second lens barrel; the second optical component comprises a primary mirror, a secondary mirror, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter, an eighth lens, and a ninth lens arranged in sequence along the light path; the primary mirror is arranged on the laser light path reflected by a target; the laser receiving focal plane component is arranged on the transmission light path of the ninth lens and is located at the focus thereof; the laser reflected by the target is incident on the primary mirror, and then reflected by the primary mirror to the secondary mirror, and after being reflected by the secondary mirror, is transmitted by the fourth lens, the fifth lens, and the sixth lens, and the transmitted laser then passes through the seventh lens, the filter, the eighth lens, and the ninth lens in sequence to the laser receiving focal plane component.

[0006] Furthermore, it also includes a first reflector disposed between the sixth lens and the seventh lens along the optical path, a second reflector disposed between the eighth lens and the ninth lens, and a third reflector disposed on the transmission optical path of the ninth lens;

[0007] The laser receiving focal plane assembly is arranged on the reflection light path of the third reflection mirror.

[0008] Further, the first lens is a positive power biconvex lens;

[0009] The second lens is a meniscus lens with negative optical power and a concave surface facing the third lens;

[0010] The third lens is a meniscus lens with positive optical power and a concave surface facing the same direction as the second lens;

[0011] The primary mirror is a positive power reflector; the secondary mirror is a negative power reflector;

[0012] The fourth lens is a meniscus lens with negative optical power and a concave surface facing the fifth lens;

[0013] The fifth lens is a meniscus lens with positive optical power and a concave surface facing the fourth lens;

[0014] The sixth lens is a meniscus lens with positive optical power and a concave surface facing the fifth lens;

[0015] The seventh lens is a meniscus lens with positive focal power and a concave surface facing the filter;

[0016] The eighth lens is a meniscus lens with positive focal power and a concave surface facing the second reflector;

[0017] The ninth lens is a positive power biconvex lens;

[0018] The first reflector, the second reflector and the third reflector are optical path folding plane reflectors.

[0019] Furthermore, the center thickness of the first lens, the second lens, and the third lens are all 2-4 mm;

[0020] The center thickness of the primary mirror is 10mm~15mm; the center thickness of the secondary mirror is 10mm~15mm; the center thickness of the fourth lens is 8mm~9mm; the center thickness of the fifth lens is 9mm~11mm; the center thickness of the sixth lens is 9mm~11mm; the center thickness of the seventh lens is 6mm~8mm; the center thickness of the eighth lens is 6mm~8mm; the center thickness of the ninth lens is 10mm~12mm; the center thicknesses of the first reflector, the second reflector and the third reflector are the same, all of which are 5mm~8mm, and the center thickness of the filter is 4mm~6mm.

[0021] Furthermore, the axial distance between the first lens and the laser output end is 10 mm to 30 mm;

[0022] The axial distance between the second lens and the first lens is 0.5 mm to 1 mm;

[0023] The axial distance between the third lens and the second lens is 0.5 mm to 1 mm;

[0024] The axial distance between the primary mirror and the secondary mirror is 60 mm to 70 mm;

[0025] The axial distance between the secondary lens and the fourth lens is 20 mm to 30 mm;

[0026] The axial distance between the fourth lens and the fifth lens is 3 mm to 4 mm;

[0027] The axial distance between the fifth lens and the sixth lens is 7 mm to 8 mm;

[0028] The distance between the sixth lens and the first reflector along the optical axis is 55 mm to 60 mm;

[0029] The distance between the first reflector and the seventh lens along the optical axis is 25 mm to 30 mm;

[0030] The axial distance between the seventh lens and the filter is 3mm~4mm;

[0031] The axial distance between the filter and the eighth lens is 0.5 mm to 1 mm;

[0032] The distance between the eighth lens and the second reflector along the optical axis is 35 mm to 40 mm;

[0033] The distance between the second reflector and the ninth lens along the optical axis is 33 mm to 40 mm;

[0034] The distance between the ninth lens and the third reflector along the optical axis direction is 30 mm to 35 mm.

[0035] Further, the focal length of the first lens is 20 mm to 30 mm, the exit surface is a spherical surface with a curvature radius of 18 mm to 25 mm, and the incident surface is a spherical surface with a curvature radius of -25 mm to -18 mm;

[0036] The focal length of the second lens is -120mm~-110mm, the exit surface is a spherical surface with a curvature radius of -8mm~-4mm, and the incident surface is a spherical surface with a curvature radius of -5mm~-9mm;

[0037] The focal length of the third lens is 30 mm to 40 mm, the exit surface is a spherical surface with a curvature radius of -65 mm to -50 mm, and the incident surface is a spherical surface with a curvature radius of -10 mm to -15 mm;

[0038] The focal length of the primary mirror is 85 mm to 95 mm, the reflecting surface is aspherical, and the vertex curvature radius is -190 mm to -170 mm;

[0039] The focal length of the secondary mirror is -60mm~-50mm, the reflecting surface is aspherical, and the vertex curvature radius is -100mm~-120mm;

[0040] The focal length of the fourth lens is -30mm to -20mm, the incident surface is a spherical surface with a curvature radius of 20mm to 25mm, and the exit surface is a spherical surface with a curvature radius of 8mm to 14mm;

[0041] The focal length of the fifth lens is 300 mm to 400 mm, the incident surface is a spherical surface with a curvature radius of -35 mm to -25 mm, and the exit surface is a spherical surface with a curvature radius of -30 mm to -25 mm;

[0042] The sixth lens has a focal length of 30 mm to 40 mm, an incident surface of a spherical surface with a curvature radius of -60 mm to -70 mm, and an exit surface of a non-spherical surface with a vertex curvature radius of -20 mm to -25 mm;

[0043] The focal length of the seventh lens is 150 mm to 190 mm, the incident surface is a spherical surface with a curvature radius of 80 mm to 90 mm, and the exit surface is a spherical surface with a curvature radius of 180 mm to 210 mm;

[0044] The focal length of the eighth lens is 200 mm to 300 mm, the incident surface is an aspherical surface, the vertex curvature radius is 40 mm to 60 mm, and the exit surface is a spherical surface, the curvature radius is 50 mm to 70 mm;

[0045] The focal length of the ninth lens is 60 mm to 70 mm, the incident surface is an aspherical surface, the vertex curvature radius is 50 mm to 70 mm, and the exit surface is a spherical surface, the curvature radius is -∞ mm to -1000 mm.

[0046] Furthermore, the laser receiving focal plane assembly includes a protective window and a focal plane, the distance between the protective window and the third reflector along the optical axis is 25 mm to 30 mm, and the distance between the focal plane and the third reflector along the optical axis is 34 mm to 39 mm;

[0047] The filter is a narrow-band filter with a transmission band of 1062nm~1066nm, and the angle between the incident light of the filter and its normal line is less than 6°.

[0048] Further, the reflection surface of the primary mirror, the reflection surface of the secondary mirror, the rear surface of the sixth lens, the front surface of the eighth lens, and the front surface of the ninth lens are 10th-order even-order aspherical surfaces;

[0049] Among the aspherical parameters of the reflecting surface of the primary mirror, k=-1.2, the 6th order coefficient is 6.0081e-013, the 8th order coefficient is -9.7792e-017, and the 10th order coefficient is 9.4095e-021;

[0050] Among the aspherical parameters of the reflecting surface of the secondary mirror, the 4th order coefficient is 3.2095e-006, the 6th order coefficient is -1.4696e-009, the 8th order coefficient is 7.6220e-013, and the 10th order coefficient is 2.0104e-017;

[0051] Among the aspheric parameters of the rear surface of the sixth lens, the 4th order coefficient is 5.8835e-007, the 6th order coefficient is 1.0015e-008, the 8th order coefficient is -2.0335e-011, and the 10th order coefficient is 7.2888e-014;

[0052] Among the aspherical parameters of the front surface of the eighth lens, the 4th order coefficient is -8.3363e-007, the 6th order coefficient is -4.9503e-010, the 8th order coefficient is 4.0588e-013, and the 10th order coefficient is -4.8668e-016;

[0053] Among the aspherical parameters of the front surface of the ninth lens, the 4th order coefficient is -1.3471e-006, the 6th order coefficient is -3.6802e-010, the 8th order coefficient is 9.8010e-015, and the 10th order coefficient is 2.2465e-018.

[0054] Furthermore, the primary mirror and the secondary mirror are made of aluminum alloy; the fourth lens is made of HZF88; the fifth lens is made of quartz glass; the sixth lens is made of HZF88; the seventh lens is made of HZF88; the eighth lens is made of HZF88; the ninth lens is made of HZF88; and the first reflector, the second reflector, and the third reflector are made of quartz glass.

[0055] Furthermore, the laser is a fiber laser; the first lens barrel and the second lens barrel are made of aluminum alloy; the primary mirror is an annular structure, with a through hole opened along its central axis, the secondary mirror is arranged corresponding to the through hole, and the secondary mirror, the fourth lens, the fifth lens, and the sixth lens are all arranged coaxially with the through hole; the focal length of the first lens is 21.40mm; the focal length of the second lens is -116.96mm; the focal length of the third lens is 34.84mm; the focal length of the primary mirror is 90.20mm; the focal length of the secondary mirror is -53.46mm; the focal length of the fourth lens is -26.91mm; the focal length of the fifth lens is 366.61mm; the focal length of the sixth lens is 34.05mm; the focal length of the seventh lens is 163.20mm; the focal length of the eighth lens is 261.71mm; the focal length of the ninth lens is 67.80mm; the focal plane is the single-photon laser receiving APD focal plane of the Geiger mode.

[0056] Beneficial effects of the present invention:

[0057] 1. The laser emitting unit of the present invention adjusts the focal length of each optical element in the first optical component of the laser emitting unit by setting the parameters of the first lens, the second lens and the third lens, thereby adjusting the laser pulse beam divergence angle of the emitted laser. At the same time, by adjusting the focal length of each optical element in the second optical component of the laser receiving unit, the laser pulse beam divergence angle can be matched with the field of view of the laser receiving unit, and rapid laser three-dimensional imaging of the target area can be performed.

[0058] 2. The laser receiving unit of the present invention adopts a secondary imaging design and a narrow-band filter design, has a strong ability to suppress stray light, and can meet the requirements of single-photon laser three-dimensional imaging for external stray light.

[0059] 3. The present invention is provided with a first reflector, a second reflector, and a third reflector, and the first reflector, the second reflector, and the third reflector all adopt optical path folding plane reflectors to form a folded optical path, thereby realizing a miniaturized design, and being able to meet the requirements of the UAV platform for large field of view, long distance, and high sensitivity laser three-dimensional imaging of the target area, as well as the requirements for payload miniaturization.

[0060] 4. The present invention sets the focal length of each optical element of the second optical assembly of a specific laser receiving unit and the chip size of the focal plane so that the instantaneous field of view of the laser three-dimensional imaging is 3°×3°.

[0061] 5. The present invention realizes a passive athermal design of the laser emitting unit and the laser receiving unit at a temperature of -40°C to 60°C by selecting the materials of each optical lens, distributing the optical focal length and coordinating the materials of the lens barrel.

[0062] 6. The present invention is equipped with a 5000Hz high repetition rate fiber laser, a Geiger mode single-photon laser receiving APD focal plane, and a catadioptric laser receiving second optical component, which can achieve 50Hz high frame rate and high sensitivity three-dimensional imaging of the target area, meeting the requirements of single-photon laser imaging and payload miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 Schematic diagram of the optical path of the laser receiving unit in an embodiment of the present invention;

[0064] Figure 2 Schematic diagram of the optical path of the laser emitting unit in an embodiment of the present invention;

[0065] Figure 3 is a transfer function diagram of the laser emitting unit at room temperature in an embodiment of the present invention;

[0066] Figure 4 It is a transfer function diagram of the laser emitting unit at -40°C in an embodiment of the present invention;

[0067] Figure 5 is a transfer function diagram of the laser emitting unit at 60° C. in an embodiment of the present invention;

[0068] Figure 6 is a diagram of the diffuse spot diameter received by the laser receiving unit at room temperature in an embodiment of the present invention;

[0069] Figure 7 This is a diagram of the diffuse spot diameter received by the laser receiving unit at -40°C in an embodiment of the present invention;

[0070] Figure 8 Graph showing the diameter of the diffuse spot received by the laser receiving unit at 60° C. in an embodiment of the present invention.

[0071] Description of reference numerals:

[0072] 101 - laser, 102 - first lens, 103 - second lens, 104 - third lens;

[0073] 201 - primary mirror, 202 - secondary mirror, 203 - fourth lens, 204 - fifth lens, 205 - sixth lens, 206 - first reflecting mirror, 207 - seventh lens, 208 - filter, 209 - eighth lens, 210 - second reflecting mirror, 211 - ninth lens, 212 - third reflecting mirror, 213 - laser receiving focal plane assembly. DETAILED DESCRIPTION

[0074] This embodiment provides a large-field-of-view single-photon laser three-dimensional imaging optical system, which is composed of a laser emitting unit and a laser receiving unit.

[0075] like Figure 2As shown, the laser emitting unit includes a laser 101, a first lens barrel with one end corresponding to the emission end of the laser 101, and a first optical component arranged in the first lens barrel, and the first optical component includes a first lens 102, a second lens 103, and a third lens 104 arranged in sequence along the emission light path of the laser 101. In this embodiment, the laser 101 is a 5000 Hz high repetition rate fiber laser, and in other embodiments of the present invention, a semiconductor laser may also be used.

[0076] In this embodiment, the first lens barrel is made of aluminum alloy; the first lens 102 is a positive double convex lens, made of HK9L, and has a focal length of 21.40 mm; the second lens 103 is a meniscus lens with negative focal length and a concave surface facing the third lens 104, made of quartz glass, and has a focal length of -116.96 mm; the third lens 104 is a meniscus lens with positive focal length and a concave surface facing the same direction as the second lens 103, made of HK9L, and has a focal length of 34.84 mm; to facilitate the measurement of lens intervals during optical assembly, the center thicknesses of the first lens 102, the second lens 103, and the third lens 104 are the same, all 3 mm, and the radius of curvature is as shown in Table 1.

[0077]

[0078] The axial distance between the first lens 102 and the emission end of the laser 101 is 15 mm; the axial distance between the second lens 103 and the first lens 102 is 0.5 mm; and the axial distance between the third lens 104 and the second lens 103 is 0.7 mm.

[0079] like Figures 3 to 5 As shown, the transfer functions of the first lens 102, the second lens 103, and the third lens 104 in the ambient temperature range of -40°C to 60°C are close to the diffraction limit, realizing a passive athermal design. When the ambient temperature changes within this range, the quality of the laser beam collimated by the first lens 102, the second lens 103, and the third lens 104 is guaranteed not to change.

[0080] like Figure 1 As shown, the laser receiving unit includes a laser receiving focal plane assembly 213, a second lens barrel, and a second optical assembly arranged in the second lens barrel; the second optical assembly includes a primary mirror 201, a secondary mirror 202, a fourth lens 203, a fifth lens 204, a sixth lens 205, a first reflector 206, a seventh lens 207, a filter 208, an eighth lens 209, a second reflector 210, a ninth lens 211, and a third reflector 212 arranged in sequence along the optical path. The second lens barrel is made of aluminum alloy.

[0081] The primary mirror 201 is arranged on the laser light path reflected by the target; in this embodiment, the primary mirror 201 is an annular structure with a through hole opened along its central axis, and the secondary mirror 202, the fourth lens 203, the fifth lens 204, and the sixth lens 205 are all arranged coaxially with the through hole.

[0082] The laser reflected by the target is incident on the primary mirror 201, and then reflected by the primary mirror 201 to the secondary mirror 202. After being reflected by the secondary mirror 202, it is transmitted by the fourth lens 203, the fifth lens 204, and the sixth lens 205, and then reflected by the first reflector 206. The reflected laser passes through the seventh lens 207, the filter 208, and the eighth lens 209 to the second reflector 210. After being reflected by the second reflector 210, it passes through the ninth lens 211, and then is reflected by the third reflector 212 to the laser receiving focal plane assembly 213. The laser receiving focal plane assembly 213 is arranged on the reflected light path of the third reflector 212 and is located at the focus of the ninth lens 211.

[0083] The primary mirror 201 is a positive power reflector made of aluminum alloy, with a center thickness of 10 mm and a focal length of 90.20 mm.

[0084] The secondary mirror 202 is a negative optical power reflector made of aluminum alloy, with a center thickness of 10 mm and a focal length of -53.46 mm.

[0085] The fourth lens 203 is a meniscus lens with negative power and a concave surface facing the fifth lens 204. The material is HZF88, the center thickness is 8.25 mm, and the focal length is -26.91 mm.

[0086] The fifth lens 204 is a meniscus lens with positive power and a concave surface facing the fourth lens 203 . The material is quartz glass, the center thickness is 10 mm, and the focal length is 366.61 mm.

[0087] The sixth lens 205 is a meniscus lens with positive power and a concave surface facing the fifth lens 204. The material is HZF88, the center thickness is 10 mm, and the focal length is 34.05 mm.

[0088] The seventh lens 207 is a meniscus lens with positive power and a concave surface facing the filter 208. The material is HZF88, the center thickness is 7 mm, and the focal length is 163.20 mm.

[0089] The eighth lens 209 is a meniscus lens with positive power and a concave surface facing the second reflector 210 . The eighth lens 209 is made of HZF88, has a center thickness of 7 mm, and a focal length of 261.71 mm.

[0090] The ninth lens 211 is a positive power biconvex lens made of HZF88, with a center thickness of 11 mm and a focal length of 67.80 mm.

[0091] The curvature radius of each optical element of the laser receiving unit is shown in Table 2.

[0092]

[0093] The first reflector 206, the second reflector 210, and the third reflector 212 are used to fold the optical path and reduce the optical system without introducing other aberrations or changing the characteristics of the optical path, so they must be plane reflectors. In this embodiment, a plane reflector for folding the optical path is used, and the material is quartz glass. The center thickness of the filter 208 is 4 mm. To facilitate processing and installation and reduce costs, the center thickness of the first reflector 206, the second reflector 210, and the third reflector 212 is the same, which is 5 mm. In other embodiments of the present invention, the first reflector 206, the second reflector 210, and the third reflector 212 may also have different thicknesses.

[0094] The reflecting surface of the primary mirror 201, the reflecting surface of the secondary mirror 202, the rear surface of the sixth lens 205, the front surface of the eighth lens 209, and the front surface of the ninth lens 211 are 10th-order even-order aspherical surfaces, wherein the aspherical surface parameters are shown in Table 3, wherein the format of each order coefficient is consistent with the expression method in the optical design software.

[0095]

[0096] The axial distance between the primary mirror 201 and the secondary mirror 202 is 67 mm, the axial distance between the secondary mirror 202 and the fourth lens 203 is 23 mm, the axial distance between the fourth lens 203 and the fifth lens 204 is 3.46 mm, the axial distance between the fifth lens 204 and the sixth lens 205 is 7.73 mm, the distance between the sixth lens 205 and the first reflector 206 along the optical axis is 56 mm, the distance between the first reflector 206 and the seventh lens 207 along the optical axis is 27 mm, the axial distance between the seventh lens 207 and the filter 208 is 3 mm, the axial distance between the filter 208 and the eighth lens 209 is 0.5 mm, the distance between the eighth lens 209 and the second reflector 210 along the optical axis is 39 mm, the distance between the second reflector 210 and the ninth lens 211 along the optical axis is 35 mm, and the distance between the ninth lens 211 and the third reflector 212 along the optical axis is 32 mm.

[0097] The laser receiving focal plane assembly 213 includes a protection window and a focal plane. The distance between the protection window and the third reflector 212 along the optical axis is 27 mm, and the distance between the focal plane and the third reflector 212 along the optical axis is 36 mm.

[0098] In order to reduce the influence of ambient light on the imaging optical system, the filter 208 is a narrow-band filter with a transmission band of 1062nm~1066nm, and the angle between the incident light of the filter 208 and its normal is less than 6°.

[0099] like Figure 6~Figure 8 As shown, the diffuse spot diameter of the laser receiving unit in the ambient temperature range of -40℃~60℃ is less than 36μm, and the pixel pitch is less than 100 microns, realizing a passive athermal design. When the ambient temperature changes within this range, the laser echo energy concentration does not change, and the lens image quality does not change.

[0100] In this embodiment, the focal length of the laser emitting unit is 15 mm, the working band is 1062 nm to 1066 nm, and the beam waist diameter is 50 μm and the beam quality is M 2 =10 laser pulse is expanded to a beam divergence angle of 4.35°, covering a field of view of 3°×3°; the focal length of the laser receiving unit is 240mm, the F number is 1.6, the working band is 1062nm~1066nm, and it can match the focal plane of a single-photon laser receiving APD in Geiger mode with an array of 128×128 and a pixel pitch of 100μm.

Claims

1. A large-field-of-view single-photon laser three-dimensional imaging optical system, comprising a laser emitting unit and a laser receiving unit, characterized in that: The laser emitting unit comprises a laser (101), a first lens barrel with one end corresponding to the emission end of the laser (101), and a first optical component arranged in the first lens barrel, wherein the first optical component comprises a first lens (102), a second lens (103), and a third lens (104) arranged in sequence along the emission light path of the laser (101); the laser (101) is a fiber laser; The laser receiving unit comprises a laser receiving focal plane assembly (213), a second lens barrel and a second optical assembly arranged in the second lens barrel; the second optical assembly comprises a primary mirror (201), a secondary mirror (202), a fourth lens (203), a fifth lens (204), a sixth lens (205), a first reflecting mirror (206), a seventh lens (207), a filter (208), an eighth lens (209), a second reflecting mirror (210), a ninth lens (211) and a third reflecting mirror (212) arranged in sequence along the optical path; The first lens barrel and the second lens barrel are made of aluminum alloy; The primary mirror (201) is arranged on the laser light path reflected by the target; The primary mirror (201) is an annular structure, a through hole is provided along its central axis, the secondary mirror (202) is arranged corresponding to the through hole, and the secondary mirror (202), the fourth lens (203), the fifth lens (204), and the sixth lens (205) are all arranged coaxially with the through hole; The laser receiving focal plane component (213) is arranged on the reflection light path of the third reflecting mirror (212) and is located at the focus thereof; The laser reflected by the target is incident on the primary mirror (201), and then reflected by the primary mirror (201) to the secondary mirror (202). After being reflected by the secondary mirror (202), the laser is transmitted by the fourth lens (203), the fifth lens (204), and the sixth lens (205). After being reflected by the first reflecting mirror (206), the transmitted laser is sequentially transmitted through the seventh lens (207), the filter (208), and the eighth lens (209). The second reflecting mirror (210) reflects the transmitted light of the eighth lens (209), and then the transmitted light is transmitted by the ninth lens (211) to the third reflecting mirror (212). The laser receiving focal plane assembly (213) receives the reflected light of the third reflecting mirror (212). The first lens (102) is a biconvex lens with positive optical power; The second lens (103) is a meniscus lens with negative optical power and a concave surface facing the third lens (104); The third lens (104) is a meniscus lens with positive optical power and a concave surface facing the same direction as the second lens (103); The primary mirror (201) is a positive power reflector; The secondary mirror (202) is a negative optical power reflector; The fourth lens (203) is a meniscus lens with negative optical power and a concave surface facing the fifth lens (204); The fifth lens (204) is a meniscus lens with positive optical power and a concave surface facing the fourth lens (203); The sixth lens (205) is a meniscus lens with positive optical power and a concave surface facing the fifth lens (204); The seventh lens (207) is a meniscus lens with positive optical power and a concave surface facing the filter (208); The eighth lens (209) is a meniscus lens with positive optical power and a concave surface facing the second reflector (210); The ninth lens (211) is a biconvex lens with positive optical power; The first reflector (206), the second reflector (210), and the third reflector (212) are optical path folding plane reflectors; The focal length of the first lens (102) is 21.40 mm; The focal length of the second lens (103) is -116.96 mm; The focal length of the third lens (104) is 34.84 mm; The focal length of the primary mirror (201) is 90.20 mm; The focal length of the secondary mirror (202) is -53.46 mm; The focal length of the fourth lens (203) is -26.91 mm; The focal length of the fifth lens (204) is 366.61 mm; The focal length of the sixth lens (205) is 34.05 mm; The focal length of the seventh lens (207) is 163.20 mm; The focal length of the eighth lens (209) is 261.71 mm; The focal length of the ninth lens (211) is 67.80 mm; The focal plane is a Geiger-mode single-photon laser receiving APD focal plane.

2. The large-field-of-view single-photon laser three-dimensional imaging optical system according to claim 1, characterized in that: The center thicknesses of the first lens (102), the second lens (103), and the third lens (104) are all 2 to 4 mm; The central thickness of the primary mirror (201) is 10 mm to 15 mm; The central thickness of the secondary mirror (202) is 10 mm to 15 mm; The central thickness of the fourth lens (203) is 8 mm to 9 mm; The central thickness of the fifth lens (204) is 9 mm to 11 mm; The central thickness of the sixth lens (205) is 9 mm to 11 mm; The central thickness of the seventh lens (207) is 6 mm to 8 mm; The central thickness of the eighth lens (209) is 6 mm to 8 mm; The center thickness of the ninth lens (211) is 10 mm to 12 mm; The center thicknesses of the first reflector (206), the second reflector (210), and the third reflector (212) are the same, all being 5 mm to 8 mm, and the center thickness of the filter (208) is 4 mm to 6 mm.

3. The large-field-of-view single-photon laser three-dimensional imaging optical system according to claim 2, characterized in that: The axial distance between the first lens (102) and the emission end of the laser (101) is 10 mm to 30 mm; The axial distance between the second lens (103) and the first lens (102) is 0.5 mm to 1 mm; The axial distance between the third lens (104) and the second lens (103) is 0.5 mm to 1 mm; The axial distance between the primary mirror (201) and the secondary mirror (202) is 60 mm to 70 mm; The axial distance between the secondary lens (202) and the fourth lens (203) is 20 mm to 30 mm; The axial distance between the fourth lens (203) and the fifth lens (204) is 3 mm to 4 mm; The axial distance between the fifth lens (204) and the sixth lens (205) is 7 mm to 8 mm; The distance between the sixth lens (205) and the first reflector (206) along the optical axis direction is 55 mm to 60 mm; The distance between the first reflector (206) and the seventh lens (207) along the optical axis is 25 mm to 30 mm; The axial distance between the seventh lens (207) and the filter (208) is 3 mm to 4 mm; The axial distance between the filter (208) and the eighth lens (209) is 0.5 mm to 1 mm; The distance between the eighth lens (209) and the second reflector (210) along the optical axis direction is 35 mm to 40 mm; The distance between the second reflector (210) and the ninth lens (211) along the optical axis is 33 mm to 40 mm; The distance between the ninth lens (211) and the third reflector (212) along the optical axis direction is 30 mm to 35 mm.

4. The large-field-of-view single-photon laser three-dimensional imaging optical system according to claim 3, characterized in that: The focal length of the first lens (102) is 20 mm to 30 mm, the exit surface is a spherical surface with a curvature radius of 18 mm to 25 mm, and the incident surface is a spherical surface with a curvature radius of -25 mm to -18 mm; The focal length of the second lens (103) is -120 mm to -110 mm, the exit surface is a spherical surface with a curvature radius of -8 mm to -4 mm, and the incident surface is a spherical surface with a curvature radius of -5 mm to -9 mm; The focal length of the third lens (104) is 30 mm to 40 mm, the exit surface is a spherical surface with a curvature radius of -65 mm to -50 mm, and the incident surface is a spherical surface with a curvature radius of -10 mm to -15 mm; The focal length of the primary mirror (201) is 85 mm to 95 mm, the reflecting surface is an aspherical surface, and the vertex curvature radius is -190 mm to -170 mm; The focal length of the secondary mirror (202) is -60 mm to -50 mm, the reflecting surface is an aspherical surface, and the vertex curvature radius is -100 mm to -120 mm; The focal length of the fourth lens (203) is -30 mm to -20 mm, the incident surface is a spherical surface with a curvature radius of 20 mm to 25 mm, and the exit surface is a spherical surface with a curvature radius of 8 mm to 14 mm; The focal length of the fifth lens (204) is 300 mm to 400 mm, the incident surface is a spherical surface with a curvature radius of -35 mm to -25 mm, and the exit surface is a spherical surface with a curvature radius of -30 mm to -25 mm; The sixth lens (205) has a focal length of 30 mm to 40 mm, a spherical incident surface with a curvature radius of -60 mm to -70 mm, and an aspherical exit surface with a vertex curvature radius of -20 mm to -25 mm; The focal length of the seventh lens (207) is 150 mm to 190 mm, the incident surface is a spherical surface with a curvature radius of 80 mm to 90 mm, and the exit surface is a spherical surface with a curvature radius of 180 mm to 210 mm; The eighth lens (209) has a focal length of 200 mm to 300 mm, an incident surface of an aspherical surface, a vertex curvature radius of 40 mm to 60 mm, and an exit surface of a spherical surface, a curvature radius of 50 mm to 70 mm; The focal length of the ninth lens (211) is 60 mm to 70 mm, the incident surface is an aspherical surface with a vertex curvature radius of 50 mm to 70 mm, and the exit surface is a spherical surface with a curvature radius of -∞ mm to -1000 mm.

5. A large field of view single-photon laser three-dimensional imaging optical system according to any one of claims 1 to 4, characterized in that: The laser receiving focal plane assembly (213) comprises a protection window and a focal plane, the distance between the protection window and the third reflector (212) along the optical axis is 25 mm to 30 mm, and the distance between the focal plane and the third reflector (212) along the optical axis is 34 mm to 39 mm; The filter (208) is a narrow-band filter with a transmission band of 1062nm to 1066nm, and the angle between the incident light of the filter (208) and its normal line is less than 6°.

6. The large-field-of-view single-photon laser three-dimensional imaging optical system according to claim 5, characterized in that: The reflection surface of the primary mirror (201), the reflection surface of the secondary mirror (202), the rear surface of the sixth lens (205), the front surface of the eighth lens (209), and the front surface of the ninth lens (211) are 10th-order even-order aspheric surfaces; Among the aspheric parameters of the reflection surface of the primary mirror (201), k=-1.2, the 6th order coefficient is 6.0081e-013, the 8th order coefficient is -9.7792e-017, and the 10th order coefficient is 9.4095e-021; Among the aspherical parameters of the reflection surface of the secondary mirror (202), the 4th order coefficient is 3.2095e-006, the 6th order coefficient is -1.4696e-009, the 8th order coefficient is 7.6220e-013, and the 10th order coefficient is 2.0104e-017; Among the aspheric parameters of the rear surface of the sixth lens (205), the 4th order coefficient is 5.8835e-007, the 6th order coefficient is 1.0015e-008, the 8th order coefficient is -2.0335e-011, and the 10th order coefficient is 7.2888e-014; Among the aspheric parameters of the front surface of the eighth lens (209), the 4th order coefficient is -8.3363e-007, the 6th order coefficient is -4.9503e-010, the 8th order coefficient is 4.0588e-013, and the 10th order coefficient is -4.8668e-016; Among the aspheric parameters of the front surface of the ninth lens (211), the 4th order coefficient is -1.3471e-006, the 6th order coefficient is -3.6802e-010, the 8th order coefficient is 9.8010e-015, and the 10th order coefficient is 2.2465e-018.

7. The large-field-of-view single-photon laser three-dimensional imaging optical system according to claim 6, characterized in that: The primary mirror (201) and the secondary mirror (202) are made of aluminum alloy; The material of the fourth lens (203) is HZF88; The material of the fifth lens (204) is quartz glass; The sixth lens (205) is made of HZF88; The seventh lens (207) is made of HZF88; The material of the eighth lens (209) is HZF88; The ninth lens (211) is made of HZF88; The first reflector (206), the second reflector (210) and the third reflector (212) are made of quartz glass.

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