Critical space laser ranging device

Abstract

The utility model discloses a critical space laser ranging device, including laser emission module and receiving module, laser emission module includes laser, emission lens barrel and emission collimating optical system, and the laser is fixed at the back end of emission lens barrel, and emission collimating optical system is located in emission lens barrel, and emission collimating optical system includes first double concave lens, first double convex lens, second double concave lens and second double convex lens, receiving module includes receiving lens barrel, focusing system and detector, and focusing system is located in receiving lens barrel, and focusing system includes third double convex lens, first meniscus and second meniscus, and the detector is fixed at the back end of receiving lens barrel. The utility model improves laser emitter's output power density and beam quality, realizes the spatial concentrated distribution of energy through the divergence angle of emission beam is suppressed, and the focusing characteristic of echo beam is optimized simultaneously, improves the optical coupling efficiency, thereby enhances the signal to noise ratio of detector receiving signal.

Description

Technical Field

[0001] This utility model relates to the field of laser ranging technology, and specifically to a critical space laser ranging device. Background Technology

[0002] Laser ranging technology, as an important branch of laser applications, can be traced back to the invention of the laser. In recent years, with the rapid increase in demand for high-precision long-range measurement in both military and civilian fields, this technology has received continuous attention from academia and industry. Current typical ranging systems mainly rely on the time-of-flight measurement principle, calculating the distance by accurately measuring the round-trip time difference of a pulsed laser over the distance to be measured.

[0003] A typical laser ranging system consists of a laser emitting unit and a signal receiving unit as its core architecture. The emitting unit includes a pulsed laser generator and a emitting optical collimating lens group, while the receiving unit comprises an optical focusing system and a photoelectric conversion device. During system operation, the laser pulse is collimated to form a parallel beam that is projected onto the target surface. After diffuse reflection from the target surface, a portion of the echo energy is focused by the receiving optical system onto the photodetector. The system calculates the target distance by accurately measuring the time interval Δt between laser pulse emission and reception, using the formula L = (c × Δt) / 2, where c is the speed of light constant.

[0004] Current conventional technologies suffer from significant technical bottlenecks: limited by the inherent physical characteristics of laser emitters—namely, the dual constraints of finite output power and large beam divergence angle—optical signals exhibit typical energy density attenuation during transmission, with the attenuation magnitude inversely proportional to the square of the transmission distance. In long-range detection applications, the echo signal intensity will attenuate below the detector's noise floor, leading to a significant deterioration in the system's signal-to-noise ratio (SNR), severely impacting the measurement accuracy and data precision of ranging parameters. This technical deficiency severely restricts the engineering application of existing laser detection systems in long-range target identification and parameter inversion, necessitating breakthroughs in performance limits through optimized optoelectronic system design. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a critical space laser ranging device to improve the output power density and beam quality of the laser transmitter. By suppressing the divergence angle of the emitted beam, it achieves spatially concentrated energy distribution and optimizes the focusing characteristics of the echo beam, thereby improving optical coupling efficiency and enhancing the signal-to-noise ratio of the detector's received signal.

[0006] This utility model provides a critical space laser ranging device, comprising:

[0007] A laser emitting module includes a laser, an emitting lens tube, and an emitting collimating optical system. The laser is fixed at the rear end of the emitting lens tube and is used to emit laser light. The emitting collimating optical system is disposed inside the emitting lens tube and is used to collimate the laser light emitted by the laser. The emitting collimating optical system includes a first biconcave lens, a first biconvex lens, a second biconcave lens, and a second biconvex lens, which are fixed in sequence from back to front inside the emitting lens tube.

[0008] A receiving module is fixed to one side of the laser emitting module. The receiving module includes a receiving lens tube, a focusing system, and a detector. The focusing system is located inside the receiving lens tube and is used to focus the laser reflected from the target. The focusing system includes a third biconvex lens, a first concave-convex lens, and a second concave-convex lens, which are fixed in sequence from front to back inside the receiving lens tube. The detector is fixed at the rear end of the receiving lens tube and located at the receiving focal point, and is used to receive the light signal reflected from the target.

[0009] Furthermore, the emission collimating optical system also includes a plane lens, which is disposed at the front end of the emission lens tube.

[0010] Furthermore, the transmitting lens tube is provided with a first mounting cavity, a first conical cavity, a second mounting cavity, a second conical cavity and a third mounting cavity in sequence from the rear end to the front end;

[0011] A rearward-facing first annular positioning platform is formed between the front end of the first mounting cavity and the rear end of the first conical cavity. The first biconcave lens is adapted to the first mounting cavity. The front end of the first biconcave lens is positioned on the first annular positioning platform. The rear end of the first biconcave lens is pressed by a first pressure ring in the first mounting cavity through a threaded connection.

[0012] The diameter of the first conical cavity gradually increases from back to front. A forward-facing second annular positioning platform is formed between the front end of the first conical cavity and the rear end of the second mounting cavity. The first biconvex lens and the second biconcave lens are respectively adapted to the second mounting cavity. The rear end of the first biconvex lens is positioned on the second annular positioning platform. A support ring is provided between the first biconvex lens and the second biconcave lens. The front end of the second biconcave lens is pressed by a second pressure ring in the second mounting cavity through a threaded connection.

[0013] The diameter of the second conical cavity gradually increases from back to front. The front end of the second conical cavity and the third mounting cavity form a forward-facing third annular positioning platform. The second biconvex lens is adapted to the third mounting cavity. The rear end of the second biconvex lens is positioned on the third annular positioning platform. The front end of the second biconvex lens is pressed by a third pressure ring in the third mounting cavity through a threaded connection. The rear end of the planar lens is positioned on the front end of the third pressure ring. The front end of the planar lens is pressed by a fourth pressure ring in the third mounting cavity through a threaded connection.

[0014] Furthermore, an adjustment shim is provided between the rear end of the second biconvex lens and the third annular positioning platform, and a plane lens shim is provided between the front end of the third pressure ring and the plane lens.

[0015] Furthermore, a photodiode is provided behind the first biconvex lens to detect whether the laser is emitting light normally and to start timing.

[0016] Furthermore, the receiving lens tube includes a fourth mounting cavity, a fifth mounting cavity, a sixth mounting cavity, and a third conical cavity arranged sequentially from front to back;

[0017] A forward-facing fourth annular positioning platform is formed between the fourth mounting cavity and the fifth mounting cavity. The third biconvex lens is adapted to the fourth mounting cavity. The rear end of the third biconvex lens is positioned on the fourth annular positioning platform. The front end of the third biconvex lens is pressed by a fifth pressure ring connected to the fourth mounting cavity through a thread.

[0018] A forward-facing fifth annular positioning platform is formed between the fifth mounting cavity and the sixth mounting cavity. The first concave-convex lens is adapted to the fifth mounting cavity. The rear end of the first concave-convex lens is positioned on the fifth annular positioning platform. The front end of the first concave-convex lens is pressed by a sixth pressure ring connected to the fifth mounting cavity through a thread.

[0019] A forward-facing sixth annular positioning platform is formed between the sixth mounting cavity and the third conical cavity. The second concave-convex lens is adapted to the sixth mounting cavity. The rear end of the first concave-convex lens is positioned on the fourth annular positioning platform. The front end of the first concave-convex lens is pressed by a seventh pressure ring connected to the sixth mounting cavity through a thread.

[0020] The diameter of the third conical cavity gradually decreases from front to back.

[0021] Furthermore, the laser includes a laser module, a laser adjustment base, and a laser mounting bracket;

[0022] The laser module is fixed on the laser adjustment base;

[0023] The laser adjustment base is located inside the laser mounting bracket. Two first set screws are threaded to the left and right sides of the laser mounting bracket, and the laser adjustment base abuts against each of the first set screws in the left and right directions. Two second set screws distributed front and back are threaded to the bottom of the laser mounting bracket, and the upper ends of the two second set screws abut against the middle of the laser adjustment base. The four corners of the laser adjustment base are fixed to the bottom of the laser mounting bracket by bolts.

[0024] Furthermore, the laser mounting bracket has first connecting blocks on the left and right sides of its front end, which are respectively fixed to the rear sides of the emitting lens tube by bolts. Second connecting blocks are respectively provided on the upper left and right sides and the lower left and right sides of the rear of the emitting lens tube. Each second connecting block is threaded with a second set screw. The second set screws on the upper left and right sides of the second connecting blocks abut against the upper end of each first connecting block, and the second set screws on the lower left and right sides of the second connecting blocks abut against the lower end of each first connecting block.

[0025] Furthermore, the laser emitting module and the receiving module are connected by a connector, which includes a connector fixed outside the laser emitting module and a connector platform located outside the receiving module.

[0026] The connecting seat is threaded with two third set screws that abut against the connecting platform respectively. The connecting seat is located in front of and behind each of the third set screws and is fixed to the connecting platform by bolts.

[0027] The connecting platform is provided with four connecting blocks, two of which extend to the upper end of the connecting seat and two of which extend to the lower end of the connecting seat. Each of the connecting blocks is threaded with a fourth set screw. The fourth set screws on the two upper connecting blocks abut against the upper end of the connecting seat, and the fourth set screws on the two lower connecting blocks abut against the lower end of the connecting seat.

[0028] Furthermore, the rear end of the receiving lens tube is provided with a fixing plate and an adjusting plate, the fixing plate being fixed to the rear end of the receiving lens tube, and the detector being fixed to the adjusting plate;

[0029] The adjusting plate is surrounded by four fifth set screws, each of which is threaded to the adjusting plate and abuts against the fixing plate. At the same time, the adjusting plate is fixed to the fixing plate by four bolts.

[0030] The rear end of the receiving lens tube is provided with a positioning groove, and the adjusting plate is located in the positioning groove. Each side of the positioning groove is threaded with a sixth set screw that abuts against the side end of the adjusting plate.

[0031] The beneficial effects of this utility model are reflected in:

[0032] This invention improves the output power density and beam quality of the laser emitter, achieves spatial concentration of energy by suppressing the divergence angle of the emitted beam, and optimizes the focusing characteristics of the echo beam to improve optical coupling efficiency, thereby enhancing the signal-to-noise ratio of the detector's received signal. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0034] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0035] Figure 2 This is a longitudinal sectional view of the laser emitting module according to an embodiment of the present invention;

[0036] Figure 3 This is an optical path diagram of the laser emitting module in an embodiment of the present invention;

[0037] Figure 4 This is a longitudinal sectional view of the receiving module according to an embodiment of the present invention;

[0038] Figure 5 This is an optical path diagram of the receiving module in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the adjustment structure of the laser and the emitting lens tube in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the adjustment structure of the laser emitting module and the receiving module in an embodiment of this utility model;

[0041] Figure 8 This is a schematic diagram of the adjustment structure of the detector and receiving lens tube in an embodiment of this utility model.

[0042] In the attached diagram, 100-laser emitting module; 110-laser; 111-laser module; 112-laser adjusting base; 113-laser mounting bracket; 114-first set screw; 115-second set screw; 120-emitting lens tube; 121-first mounting cavity; 122-first conical cavity; 123-second mounting cavity; 124-second conical cavity; 125-third mounting cavity; 126-first pressure ring; 127-support ring; 128-second pressure ring; 129-third pressure ring; 1210-fourth pressure ring; 1211-adjusting shim; 1212-planar lens shim; 1213-first connecting block; 1214-second connecting block; 1215-second set screw; 131-first biconcave lens; 132-first biconvex lens; 13 3-Second biconcave lens; 134-Second biconvex lens; 135-Planar lens; 140-Photodiode; 200-Receiver module; 210-Receiver barrel; 211-Fourth mounting cavity; 212-Fifth mounting cavity; 213-Sixth mounting cavity; 214-Third conical cavity; 215-Fifth pressure ring; 216-Sixth pressure ring; 217-Seventh pressure ring; 218-Positioning groove; 219-Sixth set screw; 221-Third biconvex lens; 222-First concave-convex lens; 223-Second concave-convex lens; 230-Detector; 231-Fixed plate; 232-Adjusting plate; 233-Fifth set screw; 300-Connector; 310-Connecting seat; 320-Connecting platform; 321-Connecting block; 330-Third set screw; 340-Fourth set screw. Detailed Implementation

[0043] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0044] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0045] like Figures 1-8 As shown, this utility model embodiment provides a critical space laser ranging device, including a laser emitting module 100 and a receiving module 200 fixed to one side of the laser emitting module 100.

[0046] Reference Figure 2The laser emitting module 100 includes a laser 110, an emitting lens tube 120, and an emitting collimating optical system. The laser 110 is fixed at the rear end of the emitting lens tube 120 and is used to emit laser light. The emitting collimating optical system is located inside the emitting lens tube 120 and is used to collimate the laser light emitted by the laser 110. The emitting collimating optical system includes a first biconcave lens 131, a first biconvex lens 132, a second biconcave lens 133, and a second biconvex lens 134, which are fixed in sequence from back to front inside the emitting lens tube 120.

[0047] In this embodiment, the transmitting collimating optical system also includes a plane lens 135, which is located at the front end of the transmitting lens barrel 120 and can protect the lens inside the transmitting lens barrel 120.

[0048] In one specific embodiment, the transmitting lens tube 120 is provided with a first mounting cavity 121, a first conical cavity 122, a second mounting cavity 123, a second conical cavity 124 and a third mounting cavity 125 in sequence from the rear end to the front end.

[0049] A rearward-facing first annular positioning platform is formed between the front end of the first mounting cavity 121 and the rear end of the first conical cavity 122. The first biconcave lens 131 is adapted to the first mounting cavity 121. The front end of the first biconcave lens 131 is positioned on the first annular positioning platform, and the rear end of the first biconcave lens 131 is pressed by a first pressure ring 126 in the first mounting cavity 121 through a threaded connection.

[0050] The diameter of the first conical cavity 122 gradually increases from back to front. A forward-facing second annular positioning platform is formed between the front end of the first conical cavity 122 and the rear end of the second mounting cavity 123. The first biconvex lens 132 and the second biconcave lens 133 are respectively adapted to the second mounting cavity 123. The rear end of the first biconvex lens 132 is positioned on the second annular positioning platform. A support ring 127 is provided between the first biconvex lens 132 and the second biconcave lens 133. The front end of the second biconcave lens 133 is pressed by a second pressure ring 128 in the second mounting cavity 123 through a threaded connection.

[0051] The diameter of the second conical cavity 124 gradually increases from back to front. The front end of the second conical cavity 124 forms a forward-facing third annular positioning platform with the third mounting cavity 125. The second biconvex lens 134 is fitted into the third mounting cavity 125. The rear end of the second biconvex lens 134 is positioned on the third annular positioning platform. The front end of the second biconvex lens 134 is pressed by a third pressure ring 129 in the third mounting cavity 125 through a threaded connection. The rear end of the plane lens 135 is positioned at the front end of the third pressure ring 129. The front end of the plane lens 135 is pressed by a fourth pressure ring 1210 in the third mounting cavity 125 through a threaded connection.

[0052] With the above structure, the first biconcave lens 131, the first biconvex lens 132, the second biconcave lens 133, the second biconvex lens 134 and the plane lens 135 can be quickly fixed in the emitting lens barrel 120, which is convenient and quick to assemble, while ensuring assembly accuracy.

[0053] Optionally, an adjusting shim 1211 is provided between the rear end of the second biconvex lens 134 and the third annular positioning platform, and a plane lens shim 1212 is provided between the front end of the third pressure ring 129 and the plane lens 135.

[0054] In this embodiment, a photodiode 140 is provided behind the first biconvex lens 132 to detect whether the laser is emitting light normally and to start timing.

[0055] Reference Figure 4 The receiving module 200 includes a receiving lens barrel 210, a focusing system, and a detector 230. The focusing system is located inside the receiving lens barrel 210 and is used to focus the laser reflected from the target being measured. The focusing system includes a third biconvex lens 221, a first concave-convex lens 222, and a second concave-convex lens 223, which are fixed from front to back inside the receiving lens barrel 210. The detector 230 is fixed at the rear end of the receiving lens barrel 210 and located at the receiving focal point, and is used to receive the light signal reflected from the target being measured. The detector 230 includes an integrated APD module.

[0056] In one specific embodiment, the receiving lens tube 210 includes a fourth mounting cavity 211, a fifth mounting cavity 212, a sixth mounting cavity 213 and a third conical cavity 214 arranged sequentially from front to back.

[0057] A forward-facing fourth annular positioning platform is formed between the fourth mounting cavity 211 and the fifth mounting cavity 212. The third biconvex lens 221 is adapted to the fourth mounting cavity 211. The rear end of the third biconvex lens 221 is positioned on the fourth annular positioning platform. The front end of the third biconvex lens 221 is pressed by a fifth pressure ring 215 in the fourth mounting cavity 211 through a threaded connection.

[0058] A forward-facing fifth annular positioning platform is formed between the fifth mounting cavity 212 and the sixth mounting cavity 213. The first concave-convex lens 222 is adapted to the fifth mounting cavity 212. The rear end of the first concave-convex lens 222 is positioned on the fifth annular positioning platform. The front end of the first concave-convex lens 222 is pressed by a sixth pressure ring 216 in the fifth mounting cavity 212 through a threaded connection.

[0059] A forward-facing sixth annular positioning platform is formed between the sixth mounting cavity 213 and the third conical cavity 214. The second concave-convex lens 223 is adapted to the sixth mounting cavity 213. The rear end of the first concave-convex lens 222 is positioned on the fourth annular positioning platform. The front end of the first concave-convex lens 222 is pressed by a seventh pressure ring 217 connected to the sixth mounting cavity 213 by a thread.

[0060] The diameter of the third conical cavity 214 gradually decreases from front to back.

[0061] With the above structure, the third biconvex lens 221, the first concave-convex lens 222, and the second concave-convex lens 223 can be quickly fixed inside the receiving lens barrel 210, making assembly convenient and quick while ensuring assembly accuracy.

[0062] like Figure 3 As shown, the laser emitted by the laser 110 is transmitted through the first biconcave lens 131 to the first biconvex lens 132. A small portion of the light is reflected by the first biconvex lens 132 to the photodiode 140. The photodiode 140 receives and detects the light and starts timing. The laser beam continues to be collimated by the second biconcave lens 133 and the second biconvex lens 134 in sequence, and finally exits through the plane lens 135, thus reaching the target under test with a very small divergence angle.

[0063] like Figure 5 As shown, the light diffused by the target returns and converges at the focal point via the third biconvex lens 221, the first concave-convex lens 222, and the second concave-convex lens 223, i.e., on the integrated APD module. After the integrated APD module detects the signal, it stops timing and then processes and calculates the relevant distance information.

[0064] In this embodiment, the laser divergence angle is significantly reduced by the collimation processing of the laser emitting module 100, and the emitted light spot exhibits a highly regular circular feature; the receiving module 200 optimizes the uniform focusing of the converging light spot, forming a well-concentrated energy distribution characteristic, thereby improving both ranging accuracy and reliability.

[0065] In some embodiments, refer to Figure 6 The laser 110 includes a laser module 111, a laser adjustment base 112, and a laser mounting bracket 113.

[0066] The laser module 111 is fixed on the laser adjustment base 112.

[0067] The laser adjustment base 112 is located inside the laser mounting bracket 113. Two first set screws 114 are threaded to the left and right sides of the laser mounting bracket 113 respectively. The laser adjustment base 112 abuts against each of the first set screws 114 in the left and right directions. Two second set screws 115 distributed front and back are threaded to the bottom of the laser mounting bracket 113. The upper ends of the two second set screws 115 abut against the middle of the laser adjustment base 112 respectively. The four corners of the laser adjustment base 112 are fixed to the bottom of the laser mounting bracket 113 by bolts.

[0068] In this embodiment, the laser adjustment base 112 can be adjusted in the front-back and left-right planes using the four first set screws 114 around it, and the laser adjustment base 112 can be swung in the front-back direction using the two second set screws 115. After adjustment, the bolts at the four corners of the laser adjustment base 112 can be tightened to fix it.

[0069] The laser mounting bracket 113 has first connecting blocks 1213 on the left and right sides of its front end, which are respectively fixed to the rear sides of the emitting lens tube 120 by bolts. The upper left and right sides and the lower left and right sides of the rear of the emitting lens tube 120 are respectively provided with second connecting blocks 1214. Each second connecting block 1214 is threaded with a second set screw 1215. The second set screw 1215 on the upper left and right sides of the second connecting block 1214 abuts against the upper end of each first connecting block 1213, and the second set screw 1215 on the lower left and right sides of the second connecting block 1214 abuts against the lower end of each first connecting block 1213.

[0070] During assembly, the position of the laser emitting module 100 and the receiving lens tube 210 can be adjusted up and down using the four second set screws 1215. After adjustment, tighten the bolts on both sides to fix the first connecting blocks 1213 on both sides of the rear of the emitting lens tube 120.

[0071] This embodiment can achieve precise adjustment of the laser with six degrees of freedom, ensuring that the output beam is strictly coaxial with the optical axis of the collimation system.

[0072] In some embodiments, refer to Figure 7 The laser emitting module 100 and the receiving module 200 are connected by a connector 300, which includes a connector 310 fixed outside the laser emitting module 100 and a connector 320 located outside the receiving module 200.

[0073] The connecting seat 310 has two threaded connections to the connecting platform 320, which are respectively abutted against the connecting platform 320. The connecting seat 310 is located in front of and behind each of the third set screws 330 and is fixed to the connecting platform 320 by bolts.

[0074] The connecting platform 320 is provided with four connecting blocks 321, two of which extend to the upper end of the connecting seat 310 and two of which extend to the lower end of the connecting seat 310. Each connecting block 321 is threaded with a fourth set screw 340. The fourth set screws 340 on the two upper connecting blocks 321 abut against the upper end of the connecting seat 310, and the fourth set screws 340 on the two lower connecting blocks 321 abut against the lower end of the connecting seat 310.

[0075] When assembling the laser emitting module 100 and the receiving module 200, the laser emitting module 100 can be adjusted by swinging left and right using the third set screw 330, and the laser emitting module 100 can also be adjusted on the front, back and upper and lower planes using the fourth set screw 340. This adjustment can ensure the parallelism of the emitted beam of the laser emitting module 100 and the two optical axes of the focusing system of the receiving module 200.

[0076] In some embodiments, refer to Figure 8 The receiving lens tube 210 has a fixing plate 231 and an adjusting plate 232 at its rear end. The fixing plate 231 is fixed to the rear end of the receiving lens tube 210, and the detector 230 is fixed on the adjusting plate 232.

[0077] Four fifth set screws 233 are distributed around the adjusting plate 232. Each fifth set screw 233 is threadedly connected to the adjusting plate 232 and abuts against the fixed plate 231. At the same time, the adjusting plate 232 is fixed to the fixed plate 231 by four bolts.

[0078] The rear end of the receiving lens tube 210 is provided with a positioning groove 218, and the adjusting plate 232 is located in the positioning groove 218. Each side of the positioning groove 218 is threaded with a sixth set screw 219 that abuts against the side end of the adjusting plate 232.

[0079] In this embodiment, the adjustment plate 232 can be adjusted in the front-to-back direction using four fifth set screws 233. When the receiving lens tube 210 and the detector 230 are assembled, they can also be adjusted up, down, left, and right using the sixth set screw 219, so as to ensure that the photosensitive surface of the detector 230 can be adjusted to the focal plane of the focusing system.

[0080] This device integrates an aspherical collimating lens group with a composite resonant cavity structure. By precisely controlling the matching relationship between the resonant cavity mode field distribution and the curvature parameters of the lens group, the transverse mode of the laser beam is effectively constrained. To address the characteristics of the echo beam, a multi-layer cascaded narrowband filter array is configured at the receiver, and an adaptive focusing module dynamically adjusts the focal point position. This module includes a closed-loop control system consisting of a piezoelectric ceramic-driven variable focal length mirror group and a real-time wavefront sensor. Specifically, a gradient refractive index medium layer is introduced at the optical interface to eliminate Fresnel loss, and the stray light suppression rate is improved to the -60dB level through optimized arrangement of the polarization beam splitter. Experimental data show that the improved system achieves a divergence angle compression to 0.1mrad, and the focal spot energy concentration is increased by 2-3 times compared to the traditional structure. Combined with a digital phase-locked low-noise amplifier circuit, the effective detection threshold is reduced to the 10nW level.

[0081] The laser 110 in this embodiment is equipped with a multi-degree-of-freedom precision adjustment design, which effectively ensures that the divergence angle and optical parameters of the emitted beam accurately meet the preset technical specifications. The detector 230 achieves precise alignment between the photosensitive surface and the focal plane of the focusing system through a multi-dimensional fine-tuning design, which significantly improves the signal-to-noise ratio of the echo signal. The laser emitting module 100 and the receiving module 200 are fixed by the connector 300 and adopt a multi-dimensional fine-tuning design to make the emission optical axis and the two optical axes of the focusing system highly collimated.

[0082] This invention improves the output power density and beam quality of the laser emitter, achieves spatial concentration of energy by suppressing the divergence angle of the emitted beam, optimizes the focusing characteristics of the echo beam, and improves optical coupling efficiency, thereby enhancing the signal-to-noise ratio of the signal received by the detector 230.

[0083] In addition, this invention also improves assembly efficiency and debugging accuracy.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A critical space laser ranging device, characterized in that, include: A laser emitting module includes a laser, an emitting lens tube, and an emitting collimating optical system. The laser is fixed at the rear end of the emitting lens tube and is used to emit laser light. The emitting collimating optical system is disposed inside the emitting lens tube and is used to collimate the laser light emitted by the laser. The emitting collimating optical system includes a first biconcave lens, a first biconvex lens, a second biconcave lens, and a second biconvex lens, which are fixed in sequence from back to front inside the emitting lens tube. A receiving module is fixed to one side of the laser emitting module. The receiving module includes a receiving lens tube, a focusing system, and a detector. The focusing system is located inside the receiving lens tube and is used to focus the laser reflected from the target. The focusing system includes a third biconvex lens, a first concave-convex lens, and a second concave-convex lens, which are fixed in sequence from front to back inside the receiving lens tube. The detector is fixed at the rear end of the receiving lens tube and located at the receiving focal point, and is used to receive the light signal reflected from the target.

2. The critical space laser ranging device according to claim 1, characterized in that, The emission collimating optical system also includes a plane lens, which is located at the front end of the emission lens tube.

3. The critical space laser ranging device according to claim 2, characterized in that, The transmitting lens tube is provided with a first mounting cavity, a first conical cavity, a second mounting cavity, a second conical cavity and a third mounting cavity in sequence from the rear end to the front end; A rearward-facing first annular positioning platform is formed between the front end of the first mounting cavity and the rear end of the first conical cavity. The first biconcave lens is adapted to the first mounting cavity. The front end of the first biconcave lens is positioned on the first annular positioning platform. The rear end of the first biconcave lens is pressed by a first pressure ring in the first mounting cavity through a threaded connection. The diameter of the first conical cavity gradually increases from back to front. A forward-facing second annular positioning platform is formed between the front end of the first conical cavity and the rear end of the second mounting cavity. The first biconvex lens and the second biconcave lens are respectively adapted to the second mounting cavity. The rear end of the first biconvex lens is positioned on the second annular positioning platform. A support ring is provided between the first biconvex lens and the second biconcave lens. The front end of the second biconcave lens is pressed by a second pressure ring in the second mounting cavity through a threaded connection. The diameter of the second conical cavity gradually increases from back to front. The front end of the second conical cavity and the third mounting cavity form a forward-facing third annular positioning platform. The second biconvex lens is adapted to the third mounting cavity. The rear end of the second biconvex lens is positioned on the third annular positioning platform. The front end of the second biconvex lens is pressed by a third pressure ring in the third mounting cavity through a threaded connection. The rear end of the planar lens is positioned on the front end of the third pressure ring. The front end of the planar lens is pressed by a fourth pressure ring in the third mounting cavity through a threaded connection.

4. The critical space laser ranging device according to claim 3, characterized in that, An adjustment shim is provided between the rear end of the second biconvex lens and the third annular positioning platform, and a plane lens shim is provided between the front end of the third pressure ring and the plane lens.

5. The critical space laser ranging device according to claim 1, characterized in that, A photodiode is provided behind the first biconvex lens to detect whether the laser is emitting light normally and to start timing.

6. The critical space laser ranging device according to claim 1, characterized in that, The receiving lens tube includes a fourth mounting cavity, a fifth mounting cavity, a sixth mounting cavity, and a third conical cavity arranged sequentially from front to back; A forward-facing fourth annular positioning platform is formed between the fourth mounting cavity and the fifth mounting cavity. The third biconvex lens is adapted to the fourth mounting cavity. The rear end of the third biconvex lens is positioned on the fourth annular positioning platform. The front end of the third biconvex lens is pressed by a fifth pressure ring connected to the fourth mounting cavity through a thread. A forward-facing fifth annular positioning platform is formed between the fifth mounting cavity and the sixth mounting cavity. The first concave-convex lens is adapted to the fifth mounting cavity. The rear end of the first concave-convex lens is positioned on the fifth annular positioning platform. The front end of the first concave-convex lens is pressed by a sixth pressure ring connected to the fifth mounting cavity through a thread. A forward-facing sixth annular positioning platform is formed between the sixth mounting cavity and the third conical cavity. The second concave-convex lens is adapted to the sixth mounting cavity. The rear end of the first concave-convex lens is positioned on the fourth annular positioning platform. The front end of the first concave-convex lens is pressed by a seventh pressure ring connected to the sixth mounting cavity through a thread. The diameter of the third conical cavity gradually decreases from front to back.

7. The critical space laser ranging device according to claim 1, characterized in that, The laser includes a laser module, a laser adjustment base, and a laser mounting bracket; The laser module is fixed on the laser adjustment base; The laser adjustment base is located inside the laser mounting bracket. Two first set screws are threaded to the left and right sides of the laser mounting bracket, and the laser adjustment base abuts against each of the first set screws in the left and right directions. Two second set screws distributed front and back are threaded to the bottom of the laser mounting bracket, and the upper ends of the two second set screws abut against the middle of the laser adjustment base. The four corners of the laser adjustment base are fixed to the bottom of the laser mounting bracket by bolts.

8. The critical space laser ranging device according to claim 7, characterized in that, The laser mounting bracket has first connecting blocks on the left and right sides of its front end, which are respectively fixed to the rear sides of the emitting lens tube by bolts. Second connecting blocks are respectively provided on the upper left and right sides and the lower left and right sides of the rear side of the emitting lens tube. Each second connecting block is threaded with a second set screw. The second set screws on the upper left and right sides of the second connecting blocks abut against the upper end of each first connecting block, and the second set screws on the lower left and right sides of the second connecting blocks abut against the lower end of each first connecting block.

9. The critical space laser ranging device according to claim 1, characterized in that, The laser emitting module and the receiving module are connected by a connector, which includes a connector fixed outside the laser emitting module and a connector platform located outside the receiving module. The connecting seat is threaded with two third set screws that abut against the connecting platform respectively. The connecting seat is located in front of and behind each of the third set screws and is fixed to the connecting platform by bolts. The connecting platform is provided with four connecting blocks, two of which extend to the upper end of the connecting seat and two of which extend to the lower end of the connecting seat. Each of the connecting blocks is threaded with a fourth set screw. The fourth set screws on the two upper connecting blocks abut against the upper end of the connecting seat, and the fourth set screws on the two lower connecting blocks abut against the lower end of the connecting seat.

10. The critical space laser ranging device according to claim 1, characterized in that, The receiving lens tube has a fixing plate and an adjusting plate at its rear end. The fixing plate is fixed to the rear end of the receiving lens tube, and the detector is fixed to the adjusting plate. The adjusting plate is surrounded by four fifth set screws, each of which is threaded to the adjusting plate and abuts against the fixing plate. At the same time, the adjusting plate is fixed to the fixing plate by four bolts. The rear end of the receiving lens tube is provided with a positioning groove, and the adjusting plate is located in the positioning groove. Each side of the positioning groove is threaded with a sixth set screw that abuts against the side end of the adjusting plate.

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