Specialized fiber bundle, optical receiving system based on specialized fiber bundle, and lidar based on optical receiving system

Abstract

The application discloses a special optical fiber bundle, an optical receiving system based on the special optical fiber bundle and a laser radar based on the optical receiving system, relates to the technical field of airborne water depth measuring laser radars, and the special optical fiber bundle comprises an input end, a first output end and a second output end; the input end is composed of a central multimode optical fiber and an annular multimode optical fiber bundle surrounding the central optical fiber; the first output end is the central multimode optical fiber; and the second output end is a circular optical fiber bundle synthesized by the annular multimode optical fiber bundle in the input end. The special optical fiber bundle provided by the application can separate a composite light echo signal into two parts of large and small fields of view, and can replace a split field of view optical reflector.

Description

Technical Field

[0001] The present application relates to the technical field of airborne water depth measurement laser radar, and in particular to a special optical fiber bundle, a light receiving system based on the special optical fiber bundle, and a laser radar based on the light receiving system. Background Art

[0002] Airborne depth measurement lidar is installed on manned aircraft (flying at an altitude of 200-1000m) or unmanned aerial vehicles (UAVs) (flying at an altitude of 10-50m) for flight operations. The emitted pulsed laser beam performs point and line scanning on the designated water surface and bottom areas from top to bottom. The light echo signals diffusely reflected from the water surface and bottom are received and stored by the optical receiving system, and the data is processed to form a point cloud map, which ultimately produces a three-dimensional topographic map of the water surface and bottom.

[0003] Each time the laser radar emits a pulse laser spot, its light receiving system will receive a composite light echo signal containing the water surface echo and the bottom echo. Due to the large absorption and scattering of light beams by water bodies such as rivers, lakes, and oceans in natural environments, the bottom light echo signal is 10 smaller than the surface light echo signal. 3 ~10 5 times, or may be far smaller than the scattered light echo caused by water scattering. In order to avoid the underwater light echo signal being submerged or difficult to collect, the optical receiving system of the airborne lidar usually adopts the "light receiving main mirror + field of view light reflector + two large and small field of view channel light receiving components" structure.

[0004] However, this traditional, typical large and small field-of-view water depth measurement optical receiving system is limited by the overall machine parameter design. It requires that the small field-of-view light receiving component and other related optical parts be arranged coaxially with the light receiving main mirror, and the large field-of-view light receiving component and other related optical parts be arranged vertically with the light receiving main mirror. The entire optical main axis structure occupies a certain length and space, which is not conducive to the lightweight and miniaturization of the airborne water depth measurement lidar. Summary of the Invention

[0005] The purpose of this application is to provide a special optical fiber bundle, an optical receiving system based on the special optical fiber bundle, and a laser radar based on the optical receiving system. The special optical fiber bundle can replace the field-of-view optical reflector in the optical receiving system to achieve lightweight and miniaturization of the entire airborne water depth measurement laser radar.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a tailored optical fiber bundle comprising: an input end, a first output end, and a second output end;

[0008] The input end is composed of a central multimode optical fiber and a ring-shaped multimode optical fiber bundle surrounding the central optical fiber;

[0009] The first output end is a central multimode optical fiber; the second output end is a circular optical fiber bundle synthesized from the annular multimode optical fiber bundle in the input end.

[0010] Optionally, the central multimode optical fiber is a multimode optical fiber or a multimode optical fiber bundle.

[0011] Optionally, when the central multimode optical fiber is a multimode optical fiber, the core diameter of the multimode optical fiber ranges from 200 to 500 μm.

[0012] Optionally, when the central multimode optical fiber is a multimode optical fiber bundle, the core diameter of each multimode optical fiber in the multimode optical fiber bundle ranges from 100 to 300 μm; and the core diameter of each multimode optical fiber in the multimode optical fiber bundle is the same.

[0013] Optionally, the core diameter of each multimode optical fiber in the annular multimode optical fiber bundle ranges from 100 to 300 μm; and the core diameter of each multimode optical fiber in the annular multimode optical fiber bundle is the same.

[0014] Optionally, the central multimode optical fiber and the multimode optical fibers in the annular multimode optical fiber bundle are made of quartz glass.

[0015] In a second aspect, the present application provides a light receiving system based on a special optical fiber bundle, comprising: a light receiving primary mirror, a special optical fiber bundle, a small field of view light receiving component, and a large field of view light receiving component;

[0016] The center of the input end of the special fiber bundle is located at the focus of the light receiving primary mirror;

[0017] The first output end of the specially made optical fiber bundle is connected to the small field of view light receiving component;

[0018] The second output end of the specially made optical fiber bundle is connected to a large-field-of-view light receiving component.

[0019] Optionally, the small field of view light receiving assembly includes a first collimating lens, a first filter, a first converging lens and a first light detector in sequence along the light path direction.

[0020] Optionally, the large-field-of-view light receiving assembly includes a second collimating mirror, a second filter, a second converging mirror and a second light detector in sequence along the light path direction.

[0021] In a third aspect, the present application provides a laser radar based on a light receiving system, comprising: a light receiving system;

[0022] The optical receiving system uses a special optical fiber bundle to replace the field-of-view reflector; the first output end of the special optical fiber bundle is coupled with the optical receiving component of the small field-of-view channel; the second output end of the special optical fiber bundle is coupled with the optical receiving component of the large field-of-view channel.

[0023] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0024] This application provides a specialized optical fiber bundle, comprising an input end, a first output end, and a second output end. The input end is composed of a central multimode optical fiber and a ring-shaped multimode optical fiber bundle surrounding the central optical fiber. The first output end is the central multimode optical fiber. The second output end is a circular optical fiber bundle formed by combining the ring-shaped multimode optical fiber bundle in the input end. The specialized optical fiber bundle provided in this application can separate composite optical echo signals into large and small field-of-view components, replacing field-of-view optical reflectors and thereby enabling lightweighting and miniaturization of airborne depth measurement lidar systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a structural diagram of a special optical fiber bundle provided in one embodiment of the present application.

[0027] Figure 2 Schematic diagram of a water depth measurement light receiving system in which a special optical fiber bundle replaces a field-of-view reflector provided in one embodiment of the present application.

[0028] Figure 3 Schematic diagram of an existing optical system provided in one embodiment of the present application.

[0029] Figure 4 This is a simulation diagram of the water surface detection receiving optical system provided in one embodiment of the present application.

[0030] Figure 5 This is a simulation diagram of the receiving field of view of the water surface detection receiving optical system provided in one embodiment of the present application.

[0031] Figure 6 This is a simulation diagram of the underwater detection receiving optical system provided in one embodiment of the present application.

[0032] Figure 7 This is a receiving field diagram of the underwater detection receiving optical system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] After being received and focused by the primary optical receiver mirror, the composite optical echo signal is separated into two parts: a small field of view (FOV) of 0 to 5 mrad and a large field of view of 5 to 35 mrad. The small field of view optical echo signal amplitude accounts for one-fifth or less of the total amplitude. In shallow waters, the small field of view channel optical receiver component can collect surface echoes and extremely weak bottom echoes. The large field of view optical echo signal amplitude accounts for four-fifths or more of the total amplitude. The large field of view channel optical receiver component is designed to avoid surface light echoes and only receive bottom light echoes in deep waters.

[0035] The composite optical echo signal is separated into large and small field-of-view components using a split-field-of-view optical reflector (i.e., a flat optical reflector with a central elliptical aperture). This split-field-of-view optical reflector is located at the focal point of the primary optical receiver, with the center of the central elliptical aperture coinciding with the primary mirror's focal point, and the major axis of the central elliptical aperture oriented at a 45-degree angle to the main optical axis of the optical receiver system. The composite optical echo signal is focused by the primary optical receiver. The small field-of-view optical echo signal forms a circular spot (φa) on the primary mirror's focal plane, completely passing through the split-field-of-view optical reflector's central elliptical aperture (designed with a minor axis a and a major axis 1.414a) to enter the coaxial small field-of-view optical receiver assembly (for surface and shallow water data). The large field-of-view optical echo signal forms an annular spot (φa inner diameter and φb outer diameter) on the primary mirror's focal plane. This spot passes completely outside the split-field-of-view optical reflector's central elliptical aperture, reflected perpendicularly to the optical axis, and enters the large field-of-view optical receiver assembly (for deep water data).

[0036] The size of the central elliptical hole (short axis a, long axis 1.414a) and the size of the elliptical shape (short axis b, long axis 1.414b) of the field-of-view light reflector are related to the design parameters of the entire light receiving system.

[0037] This traditional, typical large and small field-of-view water depth measurement optical receiving system is limited by the overall machine parameter design, requiring the small field-of-view optical receiving component and other related optical parts to be arranged coaxially with the optical receiving main mirror, and the large field-of-view optical receiving component and other related optical parts to be arranged vertically with the optical receiving main mirror.

[0038] The purpose of this application is to provide a special optical fiber bundle, an optical receiving system based on the special optical fiber bundle, and a laser radar based on the optical receiving system. The special optical fiber bundle can replace the field-of-view optical reflector in the optical receiving system to achieve lightweight and miniaturization of the entire airborne water depth measurement laser radar.

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0040] Example 1

[0041] like Figure 1 As shown, this embodiment provides a special optical fiber bundle, comprising: an input end, a first output end, and a second output end;

[0042] The input end is composed of a central multimode optical fiber and a ring-shaped multimode optical fiber bundle surrounding the central optical fiber;

[0043] The first output end is a central multimode optical fiber; the second output end is a circular optical fiber bundle synthesized from the annular multimode optical fiber bundle in the input end.

[0044] The central multimode optical fiber is a multimode optical fiber or a multimode optical fiber bundle. When the central multimode optical fiber is a multimode optical fiber, the core diameter of the multimode optical fiber ranges from 200 to 500µm. When the central multimode optical fiber is a multimode optical fiber bundle, the core diameter of each multimode optical fiber in the multimode optical fiber bundle ranges from 100 to 300µm; the core diameters of each multimode optical fiber in the multimode optical fiber bundle are the same. The core diameter of each multimode optical fiber in the annular multimode optical fiber bundle ranges from 100 to 300µm; the core diameters of each multimode optical fiber in the annular multimode optical fiber bundle are the same. The central multimode optical fiber and the multimode optical fibers in the annular multimode optical fiber bundle are made of quartz glass.

[0045] Specifically, the special fiber bundle is used to replace the field-of-view reflector. Figure 1 (a) is the input end of a special optical fiber bundle. The center of the circular end face is a central optical fiber 101 with a diameter of фa (a circular optical fiber bundle composed of one or several or dozens of 100µm to 200µm optical fibers). The annular end face in the oblique line area is an annular optical fiber bundle 102 with an inner diameter of фa and an outer diameter of фb, composed of dozens (or hundreds) of optical fibers with a core diameter of ф100 to 300µm. Figure 1 (c) in the figure is the output end of the special optical fiber bundle, where end A is the first output end, i.e. the central optical fiber (bundle) 101-A, and end B is the second output end (the circular optical fiber bundle synthesized by the annular end face optical fiber bundle in the oblique area) 102-B. Figure 1 (b) is a schematic diagram of the overall structure of the special optical fiber bundle.

[0046] The optical fibers that comprise the custom fiber bundle in this embodiment utilize commercially available high-numerical-aperture (NA = 0.22, 0.33, 0.47, or 0.66) large-core, thin-clad fibers (core diameters ranging from φ105 to 500µm). The selection of the fiber's numerical aperture, core diameter, and number of fibers are dependent on design parameters such as the primary receiving mirror and field of view of the LiDAR optical receiving system. The custom optical fibers can be fabricated and produced using conventional, mature optical processing techniques, with costs comparable to those of high-energy laser reflectors of the same aperture.

[0047] Commercial optical fibers have only three low-loss wavelength "windows" for long-distance transmission of optical signals: 850nm, 1310nm, and 1550nm. Specialized optical fiber bundles are usually selected with a length of 0.2 to 0.5 meters according to the design requirements of the entire device. The attenuation of 532nm optical signals outside the low-loss wavelength "windows" when transmitted in special optical fiber bundles is negligible.

[0048] Example 2

[0049] This embodiment provides a light receiving system based on a special optical fiber bundle, comprising: a light receiving primary mirror, a special optical fiber bundle, a small field of view light receiving component, and a large field of view light receiving component;

[0050] The center of the input end of the special fiber bundle is located at the focus of the light receiving primary mirror;

[0051] The first output end of the specially made optical fiber bundle is connected to the small field of view light receiving component;

[0052] The second output end of the specially made optical fiber bundle is connected to a large-field-of-view light receiving component.

[0053] like Figure 2 As shown in the figure, the water depth measurement optical receiving system with large and small fields of view is based on a special optical fiber bundle to separate the light echo signal. Figure 2 As shown, the input end of the specialized fiber bundle 200 is centered at the focal point of the primary optical receiving mirror 201 (the center of the input end coincides with the focal plane). The light echo signal diffusely reflected from the target is received and focused by the primary optical mirror 201. The small-field-of-view light echo signal is focused and coupled into the central optical fiber (bundle). It then passes through the output end 200-A and enters the collimator 2021, filter 2022, and convergent mirror 2023 of the small-field-of-view light receiving assembly 202, ultimately reaching the light detector 2024. The large-field-of-view light echo signal is focused and coupled into the annular fiber bundle and passes through the output end 200-B and enters the collimator 2031, filter 2032, and convergent mirror 2033 of the large-field-of-view light receiving assembly 203, ultimately reaching the light detector 2034.

[0054] The light receiving main mirror, small field of view light receiving component and large field of view light receiving component are relatively independent and together with the special optical fiber bundle constitute the water depth measurement light receiving system.

[0055] Example 3

[0056] This embodiment provides a laser radar based on a light receiving system, including: a light receiving system;

[0057] The optical receiving system uses a special optical fiber bundle to replace the field-of-view reflector; the first output end of the special optical fiber bundle is coupled with the optical receiving component of the small field-of-view channel; the second output end of the special optical fiber bundle is coupled with the optical receiving component of the large field-of-view channel.

[0058] The rest of the lidar is made up of existing off-the-shelf components.

[0059] 1) Laser

[0060] LiDAR typically uses a laser as a light source to emit a laser beam. This can be done using existing semiconductor lasers or fiber lasers, which are widely used in various LiDAR systems and offer high stability, high power, and low noise.

[0061] 2) Scanning system

[0062] A scanning system is used to change the direction of the laser beam to scan different areas. This can be achieved using technologies such as mechanical scanning, optical phased arrays, or microelectromechanical systems (MEMS). These technologies are already available and widely used in the lidar field.

[0063] 3) Signal processing system

[0064] The signal processing system receives and processes the signals collected by the optical receiving system. This system may include components such as a high-speed data acquisition (AD) module, a digital signal processor (DSP), or a field-programmable gate array (FPGA). These components efficiently convert optical signals into digital signals and perform filtering, amplification, and analysis to extract useful information.

[0065] 4) Power management system

[0066] The power management system is responsible for providing a stable power supply to the various components of the LiDAR. This may include components such as power converters, voltage regulators, and batteries. These components are readily available and can be selected and configured based on the specific needs of the LiDAR.

[0067] Please note that the above are just some examples of off-the-shelf components that may be used in lidar and do not constitute a complete lidar system. Actual lidar systems may include many more components and subsystems.

[0068] In addition, this application also provides an example of a receiving optical system design scheme, which can be as follows:

[0069] 1. Design of receiving optical system:

[0070] 1.1 Design of receiving optical system:

[0071] Design requirements: The light receiving aperture is approximately 100mm, the light receiving field of view is 0-21mrad, with a small field of view of 0-5mrad and a large field of view of 5-21mrad. Optical lenses should be off-the-shelf products whenever possible. The photosensitive surface of the surface light detector should be Φ0.5mm, and the photosensitive surface of the underwater light detector should be Φ8mm.

[0072] The receiving optical system mainly completes the reception of ranging laser echoes. Improving the receiving efficiency and effectively distinguishing the echoes from the water surface and the bottom are the key points in the design of the receiving optical system. In order to achieve the optical system design requirements of miniaturization, lightness and low power consumption of the receiving optical system, and taking into account the advantages and disadvantages of various optical path forms and the actual needs of this application, this optical system uses a field mirror to distinguish the echoes from the water surface and the bottom. Figure 3 shown.

[0073] The optical system adopts a Kepler transmission-type long-range optical path with a main mirror diameter of 110 mm. The link includes a surface detection link and a bottom detection link. The surface detection link and the bottom detection link are split by a field mirror. The field mirror is a reflector with a central opening (i.e., a split-field reflector) located at the focus of the main mirror, which is conducive to reducing the size of the opening, thereby reducing the receiving loss of the bottom detection link.

[0074] 1.2 Analysis of optical receiving system components:

[0075] The optical receiving system is mainly composed of Kepler beam expander telescope group, field mirror, focusing mirror and other devices.

[0076] The Keplerian beam expander telescope assembly consists of an aspheric primary lens and a spherical collimating lens. The primary light-receiving lens has an effective aperture of 110mm and a focal length of 200mm, while the collimating lens has an effective aperture of 20mm and a focal length of 25mm. Together with the primary lens, they form a Keplerian telescope with a beam expansion ratio of 8. The surface focusing lens has an effective aperture of 20mm and a focal length of 12.5mm, resulting in an effective focal length of approximately 100mm when combined with the telescope assembly. The underwater focusing lens has an effective aperture of 20mm and a focal length of 50mm, resulting in an effective focal length of approximately 400mm when combined with the telescope assembly. The field lens has an elliptical effective aperture, with overall dimensions of 5.66mm (major axis) x 4mm (minor axis), and a central aperture of 1.97mm (major axis) x 1.39mm (minor axis). It is silver-coated and protectively silver-coated.

[0077] 1.3 Optical receiving system simulation:

[0078] According to the schematic diagram of the receiving optical system and the above-mentioned design parameter analysis, the receiving optical system can be simulated using the optical design software Zemax.

[0079] Since the photosensitive surface of the water surface detector is small, about 0.5mm, the receiving field of view is required to be ≤5mrad. After optical simulation, the diameter of the water surface detection receiving optical system is 110mm and the focal length is about 101mm. Then the receiving field of view of the water surface detection optical system is 0.5mm / 101mm=4.95mrad, which meets the requirement that the receiving field of view of the water surface detection receiving optical system is ≤5mrad. Figure 4 、 5 Shown are simulation diagrams of the water surface detection receiving optical system and the receiving field of view simulation diagram.

[0080] Since the photosensitive surface of the underwater detector is relatively large, about φ8mm, the receiving field of view is required to be 5~21mrad. After optical simulation, the aperture of the surface detection receiving optical system is φ110mm and the focal length is about 426mm. The receiving field of view of the surface detection optical system is 8mm / 426mm=18.8mrad. The size of the elliptical hole in the center of the field mirror is (major axis) 1.97×(minor axis) 1.39mm. The focal length of the main mirror is 200mm. The field angle of the light reflected by this mirror is ≥1.39mm / 200mm=6.9mrad. The receiving field of view of the underwater detector is 6.9~18.8mrad, which meets the receiving field of view requirement of 5~21mrad for the underwater detection receiving optical system. Figure 6 、 7 As shown, there are simulation diagrams of the underwater detection receiving optical system and the receiving field of view.

[0081] 1.4 Special fiber bundle replaces field mirror (field mirror):

[0082] According to the parameter design of the optical receiving system in this example, the elliptical outer dimensions of the field mirror are (major axis) 5.66×(minor axis) 4mm, and the central elliptical aperture dimensions are (major axis) 1.97×(minor axis) 1.39mm. Therefore, the parameters selected for the production of the special fiber bundle input end are: the central fiber bundle diameter is Φ1.39mm, the inner diameter of the fiber bundle surrounding the central fiber bundle is Φ1.39mm, and the outer diameter is Φ4mm.

[0083] In summary, this application has the following technical effects:

[0084] (1) Thanks to the "relay" function of the specially designed optical fiber bundle, the primary mirror, the small field of view light receiving assembly, and the large field of view light receiving assembly are relatively independent and can be installed, debugged, and reassembled separately. This separate design makes the installation and adjustment process simpler and reduces the technical difficulty.

[0085] (2) The bendability of the custom fiber bundle allows for flexible design of its length and installation location based on the overall system requirements. Therefore, the large-field-of-view and small-field-of-view light receiving components, as independent units, do not need to have their optical axes coaxial with or perpendicular to the primary mirror. They can be flexibly installed at any location within the system, thus optimizing the internal space utilization of the LiDAR system.

[0086] (3) The optical echo signals of the large field of view and the small field of view are coupled into the optical detector from the output ends B and A of the special optical fiber bundle, respectively. Drawing on the conventional process of commercial optical fiber collimators in the field of optical communications, the selection of commercial optical collimators, filters, and light converging mirrors with smaller light apertures helps to reduce costs and achieve miniaturization of the system.

[0087] (4) Due to the limitation of the numerical aperture in fiber transmission, optical signals larger than the field of view of the fiber cannot be transmitted in the fiber. As long as the numerical aperture design of the light receiving primary mirror matches the numerical aperture selection of the special fiber bundle, and the large field of view and small field of view light receiving components adopt a tube-enclosed extinction structure, the entire light receiving system will not be disturbed by any stray light outside the set light receiving field of view (i.e., the field of view greater than 35mrad).

[0088] (5) The lightweighting and volume reduction of large field of view and small field of view light receiving components will help the entire LiDAR device to be lightweight and miniaturized.

[0089] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A light receiving system based on a special optical fiber bundle, characterized in that: include: Light receiving primary mirror, special optical fiber bundle, small field of view light receiving assembly and large field of view light receiving assembly; The specially made optical fiber bundle comprises: an input end, a first output end, and a second output end; The input end is composed of a central multimode optical fiber and an annular multimode optical fiber bundle surrounding the central optical fiber; the first output end is the central multimode optical fiber; the second output end is a circular optical fiber bundle synthesized from the annular multimode optical fiber bundle in the input end; The center of the input end of the special fiber bundle is located at the focus of the light receiving primary mirror; The first output end of the specially made optical fiber bundle is connected to the small field of view light receiving component; The second output end of the specially made optical fiber bundle is connected to a large-field-of-view light receiving component.

2. The optical receiving system based on a special optical fiber bundle according to claim 1, characterized in that: The small-field-of-view light receiving assembly comprises a first collimating mirror, a first filter, a first converging mirror and a first light detector in sequence along the light path direction.

3. The optical receiving system based on a special optical fiber bundle according to claim 1, characterized in that: The large-field-of-view light receiving assembly comprises a second collimating mirror, a second filter, a second converging mirror and a second light detector in sequence along the light path direction.

4. The optical receiving system based on a special optical fiber bundle according to claim 1, characterized in that: The central multimode optical fiber is a multimode optical fiber or a multimode optical fiber bundle.

5. The optical receiving system based on a special optical fiber bundle according to claim 4, characterized in that: When the central multimode optical fiber is a multimode optical fiber, the core diameter of the multimode optical fiber ranges from 200 to 500 μm.

6. The optical receiving system based on a special optical fiber bundle according to claim 4, characterized in that: When the central multimode optical fiber is a multimode optical fiber bundle, the core diameter of each multimode optical fiber in the multimode optical fiber bundle ranges from 100 to 300 μm; and the core diameter of each multimode optical fiber in the multimode optical fiber bundle is the same.

7. The optical receiving system based on a special optical fiber bundle according to claim 1, characterized in that: The core diameter of each multimode optical fiber in the annular multimode optical fiber bundle ranges from 100 to 300 μm; the core diameter of each multimode optical fiber in the annular multimode optical fiber bundle is the same.

8. The optical receiving system based on a custom optical fiber bundle according to claim 1, characterized in that: The central multimode optical fiber and the multimode optical fibers in the annular multimode optical fiber bundle are made of quartz glass.

9. A laser radar based on a light receiving system based on a special optical fiber bundle according to any one of claims 1 to 8, characterized in that: include: Light receiving system; The light receiving system adopts a special optical fiber bundle; The first output end of the specially made optical fiber bundle is coupled to the light receiving component of the small field of view channel; The second output end of the special optical fiber bundle is coupled to the light receiving component of the large field of view channel.

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