Space Optical Laser Reflector

Abstract

The invention discloses a spatial optical laser reflector, which comprises: a three-right-angle reflection surface reflection structure, which is used for accurately returning an incident laser beam along the original optical path direction; a diffraction phase shaping structure, which is a series of periodic sub-wavelength concentric annular gratings, arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure, and is used for interfering and shaping the laser beam reflected by the three-right-angle reflection surface reflection structure through its surface grating to form a light spot that meets the requirements at a target receiving position.

Description

Technical Field

[0001] The invention relates to the field of laser ranging, and in particular to a space optical laser reflector. Background Art

[0002] Laser reflector is a special retroreflector, which consists of three mutually perpendicular (90°) reflection surfaces and one incident (exit) surface. It is a tetrahedral cone prism with spatial directional emission characteristics. Ideally, a laser beam is incident from the bottom surface of the corner cube prism, and after being reflected by the three right-angle surfaces in sequence, the outgoing light will be emitted in the opposite direction parallel to the incident light.

[0003] In the field of aerospace, laser reflectors are essential components for tracking and measuring the distance of satellites and aerospace vehicles. They are passive optical devices mounted on the surface of aircraft. Their function is to reflect the ranging laser beam along the original optical path in the incident direction to achieve long-distance precision measurement between the ranging point and the aircraft. In addition, they are also widely used in the precision measurement of objects such as long-distance targets, missiles, and launch vehicles.

[0004] In actual engineering applications, in order to increase the reflection area, the structure of the laser reflector is usually composed of a plurality of corner reflector array structures. Compared with a single corner reflector, it can significantly reduce the size and weight, improve the far-field angle of the cooperative target, and optically compensate for the distortion of the laser caused by atmospheric inhomogeneity during transmission. In order to achieve effective measurement of scientific targets, the laser reflector assembly should have a high laser reflectivity and a small divergence characteristic to ensure that the reflected signal has sufficient light intensity. For example, for low-orbit satellites, laser cooperative targets usually adopt a hemispherical or semi-conical structure so that the effective emission area of ​​the array is symmetrically distributed in the observation area and as uniform as possible to ensure that ranging can be performed even at low elevation angles; for high-orbit satellites, since a large reflection area is generally required, a planar circular arrangement is adopted.

[0005] As a traditional laser reflector, its working technical status (divergence angle, maximum tilt angle, effective emission area, emissivity, far-field diffraction spot, speed aberration compensation, etc.) is determined by the characteristics of the reflector (shape, size, angular error). For example, the angular error of the right-angle surface coating directly determines the far-field diffraction spot and speed aberration compensation of the laser cooperation target; the reflector aperture determines the spot divergence angle. Theoretical and experimental proofs: when the right angle of the corner reflector is deviated, the six sub-beams of the outgoing light are in a separated state, each with a small angle with the incident light, and the energy distribution of the diffraction spot is also different from that of the ideal corner reflector. The far-field energy distribution of the ideal reflector without angle deviation is the central Airy disk, and the far-field energy distribution of the reflector with deviation is surrounded by 6 sub-annular spots in addition to the central Airy disk.

[0006] For high-speed targets, due to the velocity aberration effect, when the laser beam is pointed at a satellite or other high-speed aircraft, the outgoing light will have a deviation angle relative to the incident light direction, and the center of the reflected beam spot will deviate from the SLR position. In actual design, in order to reduce the influence of aberration, the aberration compensation method is usually used to design the satellite-borne corner reflector, and the processing deviation is changed to make the normalized energy on the ring with the velocity difference angle as the radius reach the optimal value. The angle compensation method can separate the outgoing sub-beams by designing the corresponding right-angle surface deviation, thereby increasing the laser light energy density and detection probability at the receiving position, but the energy utilization efficiency in the ring is very low, less than 10%.

[0007] For low-speed targets, an unbiased reflector can be used, but the central Airy disk is a typical Bessel function distribution, which is strong in the middle and low on both sides, and the energy is uneven, which can easily affect the number of echo photons and detection efficiency, resulting in unstable feedback data. Summary of the invention

[0008] The embodiment of the present invention provides a spatial optical laser reflector to solve the above-mentioned problems in the prior art.

[0009] An embodiment of the present invention provides a spatial optical laser reflector, comprising:

[0010] The three right-angle reflection surface reflection structure is used to accurately return the incident laser beam along the original optical path direction;

[0011] The diffraction phase shaping structure is a series of periodic sub-wavelength concentric annular gratings, which are arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure. It is used to diffract the laser beam reflected by the three-right-angle reflection surface reflection structure through its surface grating, and then interfere and shape it at the target receiving position to form a light spot that meets the requirements.

[0012] Preferably, the three right-angle reflecting surface reflection structure is a solid reflector or a hollow reflector, wherein the solid reflector includes three mutually perpendicular reflecting surfaces and one incident and exiting surface, is a tetrahedral conical prism, and has a spatial directional emission characteristic; the hollow reflector is composed of three mutually perpendicular reflecting surfaces.

[0013] Preferably, when the three-right-angle reflection surface reflection structure is a solid reflector, the diffraction phase shaping structure is a series of periodic sub-wavelength concentric annular gratings engraved or etched on the incident and exit surfaces of the three-right-angle reflection surface reflection structure; or, the diffraction phase shaping structure is a phase film of a plane arranged at the incident and exit surfaces of the three-right-angle reflection surface reflection structure, and a series of periodic sub-wavelength annular fan gratings are engraved or etched on the incident surface of the phase film.

[0014] Preferably, when the three-right-angle reflection surface reflection structure is a hollow reflector, the diffraction phase shaping structure is a plane phase film arranged at the incident surface position of the three-right-angle reflection surface reflection structure, and the incident surface of the phase film is engraved or etched with a series of periodic sub-wavelength annular fan gratings.

[0015] Preferably, the series of periodic parameters specifically include: the number of grating lines, groove depth, shape, and period.

[0016] Preferably, the material of the three right-angle reflection surface reflection structure includes: glass, engineering plastics, and metal, wherein the material of the solid reflector when used in a space environment is fused quartz glass.

[0017] Preferably, the right-angle reflection surface or the reflection surface film layer of the three-right-angle reflection surface reflection structure has a profile accuracy of at least 1 / 10λ.

[0018] Preferably, the diffraction phase shaping structure specifically includes: a two-step, multi-step, continuous phase binary optical element structure, a sub-wavelength microstructure and a continuous phase structure.

[0019] Preferably, the phase film is arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure by means of mechanical housing connection or gluing.

[0020] By adopting the embodiment of the present invention and utilizing the principle of laser optical monochromatic diffraction interference synthesis, a specific centrally symmetrical subwavelength annular phase structure that meets the requirements and has a certain regularity is added to the surface (or position) of the laser reflector to achieve high control and concentration of the reflected light field energy. This can greatly improve the reflection efficiency of the cooperative target, greatly increase the reflection energy and effective distance of the target, and reduce the power consumption, volume and weight of the detection equipment, with more obvious effects.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 is a functional structure diagram of a space optical laser reflector according to an embodiment of the present invention;

[0024] Figure 2is a schematic structural diagram of a solid reflector according to an embodiment of the present invention;

[0025] Figure 3 is a schematic structural diagram of a hollow reflector according to an embodiment of the present invention;

[0026] Figure 4 1 is a schematic diagram of a light spot pattern ring of a conventional high-speed detection target after shaping according to an embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of a light spot pattern ring of a received light field after high-speed detection target shaping according to an embodiment of the present invention;

[0028] Figure 6 1 is a schematic diagram of a center flat top of a light spot pattern of a received light field after conventional low-speed detection target shaping according to an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of a central flat top of a received light field spot pattern after low-speed detection target shaping according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] The diffraction phase technology based on the theory of optical diffraction and interference is an increasingly mature technology that can precisely control the geometric size and energy of each level of the laser diffraction spot spectrum to achieve the expected distribution of diffraction light intensity.

[0032] Binary optics is an emerging branch of optics developed based on the theory of light wave diffraction. It is a frontier discipline formed by the mutual penetration and intersection of optics and microelectronics. Based on the theory of light wave diffraction, binary optical devices use computer-aided design, ultra-large-scale integrated circuit manufacturing technology or other micron-nano micro-machining methods to etch two or more step depths and continuous relief structures on the substrate or traditional optical surface to achieve functions that are difficult for traditional optics to have. Binary optics promotes the miniaturization, arraying and integration of optical systems, and plays an increasingly important role and has broad application prospects in modern defense and industrial fields such as space technology, laser processing, computing technology and information processing, optical fiber communication and biomedicine. There are many manufacturing processes for binary optical elements (BOE), including multi-step and continuous phase binary optical element processing technology. The former includes etching and thin film deposition, and the latter includes laser beam direct writing, electron beam direct writing and diamond turning. In addition, there are new manufacturing methods such as excimer laser processing and grayscale masking. The processing technology of binary optical elements continues to mature, and currently has achieved processing with a precision of tens of nanometers or even several nanometers.

[0033] The technology used to control the phase of the laser wavefront is called laser beam shaping technology, which has important applications in many fields of optical engineering. Laser spot shapes of various shapes are required in laser processing and treatment, including flat-top, rectangular, annular, and linear shapes. In super-resolution laser beam shaping, phase plates with annular phase distributions of different radii are used to modulate the far-field diffracted light, which can realize various annular distribution diffraction fields.

[0034] Etching a grating on the reflector through the diffraction phase technology can greatly improve the utilization efficiency and uniformity of the laser far-field spot of the satellite-borne laser reflector. For high-speed targets that need to consider the speed difference effect, the reflector's far-field spot can be shaped into a ring shape through the diffraction phase technology, which can at least increase the effective utilization energy to more than 40%, and theoretically close to 100%; for low-speed targets that do not need to consider the speed difference effect, the reflector's far-field spot can be shaped into a flat-top light through the diffraction phase technology, which can greatly homogenize the spot and improve the detection uniformity, stability and site observation efficiency.

[0035] The purpose of the embodiments of the present invention is to improve the reflection ability of the laser reflector, improve the spot energy and utilization efficiency of the far-field diffraction area of ​​the laser reflector, and on this basis, on the one hand, it can greatly broaden the detection capability of the photoelectric ranging system, while further reducing the size and weight of the equipment.

[0036] Based on the diffraction interference theory, the embodiment of the present invention creatively proposes a phase reflector. By adding a regular grating etched on the entry and exit optical surface (or position) of the reflector, the optical far-field energy density and uniformity of the reflector target can be greatly enhanced, and the detection capability and distance of the optoelectronic system can be greatly improved, thereby further reducing the cost and volume of the equipment. This has important engineering significance and practical economic value, especially for space detection systems with cooperative targets.

[0037] The embodiment of the present invention is based on the diffraction phase technology and utilizes the optical monochromatic diffraction interference synthesis principle of the laser. It uniquely proposes to add a specific and regular micron-submicron-nanoscale subwavelength annular grating on the surface of the laser reflector through micro-machining methods such as laser lithography and chemical etching to achieve a high degree of control and concentration of the far-field light field energy of the reflector target, thereby greatly improving the reflection efficiency of the cooperative target and the detection capability of the system.

[0038] According to the embodiments of the present invention, the control, concentration and homogenization of the far-field spot pattern of the target receiving light field of the laser reflector can be accurately designed. Typical applications include 1) the ring-shaped ring-shaped control of the target light field of the reflector for high-speed target sky detection 2) the flat-top homogenization of the target light field of the reflector for low-speed target detection.

[0039] The technical solution of the embodiment of the present invention is described in detail below.

[0040] According to an embodiment of the present invention, a spatial optical laser reflector is provided. Figure 1 is a functional structure diagram of a space optical laser reflector according to an embodiment of the present invention. Figure 1 As shown, the spatial optical laser reflector according to an embodiment of the present invention specifically includes:

[0041] The three-right-angle reflective surface reflective structure 1 is used to accurately return the incident laser beam along the original optical path direction; the three-right-angle reflective surface reflective structure 1 is a solid reflector or a hollow reflector, wherein the solid reflector includes three mutually perpendicular reflective surfaces and an incident and exiting surface, and is a tetrahedral conical prism with spatial directional emission characteristics; the hollow reflector is composed of three mutually perpendicular reflective surfaces. The materials of the three-right-angle reflective surface reflective structure 1 include: glass, engineering plastics, and metal, wherein the material of the solid reflector is fused quartz glass when used in a space environment. The right-angle reflective surface or reflective surface film layer of the three-right-angle reflective surface reflective structure 1 has a profile accuracy of at least 1 / 10λ.

[0042] The diffraction phase shaping structure 2 is a series of periodic sub-wavelength concentric annular gratings, which are arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure 1, and are used to form a light spot that meets the requirements at the target receiving position after the laser beam reflected by the three-right-angle reflection surface reflection structure 1 is diffracted by the surface grating. Among them, the series of periodic parameters specifically include: the number of grating lines, groove depth, shape, and period.

[0043] When the three-right-angle reflector reflective structure 1 is a solid reflector, the diffraction phase shaping structure 2 is a series of periodic sub-wavelength concentric annular gratings carved or etched on the incident and exit surfaces of the three-right-angle reflector reflective structure 1; or, the diffraction phase shaping structure 2 is a phase sheet of a plane arranged at the incident and exit surfaces of the three-right-angle reflector reflective structure 1, and a series of periodic sub-wavelength annular fan gratings are carved or etched on the incident surface of the phase sheet. When the three-right-angle reflector reflective structure 1 is a hollow reflector, the diffraction phase shaping structure 2 is a phase sheet of a plane arranged at the incident and exit surfaces of the three-right-angle reflector reflective structure 1, and a series of periodic sub-wavelength annular fan gratings are carved or etched on the incident surface of the phase sheet. Among them, the phase sheet is arranged on the incident and exit surfaces of the three-right-angle reflector reflective structure 1 by mechanical shell connection or gluing.

[0044] The diffraction phase shaping structure 2 specifically includes: two-step, multi-step, continuous phase binary optical element structure forms, as well as sub-wavelength microstructure and continuous phase structure.

[0045] In summary, if Figure 1 As shown, from the perspective of functional structure, a space satellite-borne phase laser reflector of an embodiment of the present invention can realize two functions: 1) diffraction phase shaping, 2) reflection laser original optical path return, and the corresponding structure includes a diffraction phase shaping structure 2 and a three-right-angle reflection surface reflection structure 1 (corner cube prism). The diffraction phase shaping structure 2 is used to realize the shaping, concentration and homogenization of the far-field spot energy received by the target; the three-right-angle reflection surface structure 1 (corner cube prism) is used to realize the accurate return of the original optical path direction of the laser beam.

[0046] The above structure of the embodiment of the present invention is summarized as follows:

[0047] 1. The three right-angle reflective surface structure 1 (corner cube prism) can be a solid or hollow retroreflector. The solid reflector is composed of three mutually perpendicular (90°) reflective surfaces and an incident (exit) surface. It is a tetrahedral cone prism with spatial directional emission characteristics; the hollow reflector is composed of three mutually perpendicular (90°) reflective surfaces;

[0048] 2. For solid reflectors, such as Figure 2As shown, the diffraction phase shaping structure 2 is a series of periodic sub-wavelength concentric annular gratings engraved or etched on the incident and exiting surfaces of the reflector, so that the laser beam reflected by the reflector is diffracted by the surface grating and then interfered and shaped at the target receiving position to form a circular ring belt, flat top light or other forms of light spots that meet the requirements;

[0049] 3. For hollow reflectors, such as Figure 3 As shown, the diffraction phase shaping structure 2 adds a plane phase sheet to the incident surface of the reflector, and carves or corrodes a series of periodic sub-wavelength annular fan gratings on the incident surface of the phase sheet, so that the laser beam reflected by the reflector is diffracted by the surface grating, and then interferes and shapes at the target receiving position to form a circular ring belt, flat top light or other forms of light spots that meet the requirements;

[0050] 4. According to the target detection performance index (distance, speed) requirements of the optoelectronic system, change the specific parameters of the phase photo (number of grating lines, groove depth, shape, period) to meet the different detection needs of the target light field (ring belt, central flat top);

[0051] The present invention creatively proposes for the first time in the field of laser reflector technology to use diffraction phase technology to manufacture and design laser optical reflectors. The reflector designed according to the present invention can greatly improve the reflection ability of the laser reflector. Compared with the traditional reflector, the light spot energy and utilization efficiency in the far-field diffraction area of ​​the laser reflector can be improved. While broadening the detection capability of the photoelectric ranging system, the power, caliber, volume and weight of the detection equipment can be further greatly reduced. In particular, it has very good engineering application value and economic significance for cooperative target space laser detection without atmospheric interference and the field of lasers using a corner cone prism reflection cavity structure.

[0052] The above technical solution of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0053] like Figure 1 As shown, the reflector structure of the embodiment of the present invention is composed of a diffraction phase shaping structure 2 and a three-right-angle reflection surface reflection structure 1 (corner cube prism). The diffraction phase shaping structure 2 is used to achieve the shaping, concentration and homogenization of the far-field light spot energy received by the target; the three-right-angle reflection surface structure 1 (corner cube prism) is used to achieve the accurate return of the original optical path direction of the laser beam.

[0054] See also Figure 1 As shown, the reflector designed in the present invention can mainly realize two functions, 1) for reflecting laser shaping, 2) for realizing the return of the original optical path of the detection laser; correspondingly, it includes a diffraction phase shaping structure 2 and a three-right-angle reflection surface structure 1 (corner cube prism). The reflector diffraction phase shaping structure 2 is used to realize the shaping, concentration and homogenization of the far-field spot energy received by the target; the three-right-angle reflection surface structure 1 (corner cube prism) is used to realize the accurate return of the original optical path direction of the laser beam.

[0055] In this embodiment, according to different uses, the diffraction phase shaping structure 2 is a series of periodic micron, submicron or nanometer gratings with the same concentric rings engraved or etched on the incident and exit surfaces of the reflector, so that the laser beam reflected by the reflector is diffracted by the surface grating and then interfered and shaped at the target receiving position to form a circular ring belt, flat top light or other forms of light spots that meet the requirements;

[0056] In this embodiment, the reflected laser light is sequentially returned to the original direction of the optical path through the three right-angle reflection surface reflection structure 1 (corner cube prism). According to different uses, the three right-angle reflection surface reflection structure 1 (corner cube prism) includes a solid right-angle prism and a hollow right-angle prism.

[0057] See also Figure 1 and Figure 2 As shown, for a solid reflector, the diffraction phase shaping structure 2 can be used as a part of the solid reflector and directly etched on the incident and exiting surfaces of the solid reflector; or it can be used as a separate phase diffraction plate and placed on the incident and exiting outer surfaces of the solid reflector by mechanical housing connection or gluing. Regardless of the method, in order to ensure the in-phase propagation of the shaped light spot, the surface accuracy of the incident and exiting outer surfaces of the solid reflector is at least 1 / 20λ.

[0058] See also Figure 1 and Figure 3 As shown, for the hollow reflector, the diffraction phase shaping structure 2 is placed as a single phase diffraction plate at the incident and exit outer surface of the hollow reflector by mechanical shell connection or gluing;

[0059] The material of the right-angle prism can be glass, engineering plastics, metal and other optical materials. Considering the requirements of the space environment, the material of the solid right-angle prism is fused quartz glass when used in the space environment. According to the characteristics of the reflection target (speed, track), the three right-angle outer sides can be coated (aluminum, gold, silver) or uncoated, and the corresponding light path reflection surface can be internal reflection and film layer reflection. Regardless of the method, the surface accuracy of the right-angle surface affects the propagation and regulation of the shaped light spot. For medium and high precision reflectors, the surface accuracy of the right-angle reflection surface or the reflection surface film layer is at least 1 / 10λ.

[0060] In this embodiment, different structures and processing methods of the diffraction phase shaping structure 2 can be selected according to different uses, diffraction efficiency and economic cost. The diffraction phase shaping structure can include two-step, multi-step and continuous phase binary optical elements and other structural forms. For different step (2, 4, 8, 16) phase devices, the corresponding diffraction efficiencies are 40.5%, 81%, 94.9%, and 98.6%, respectively. By using sub-wavelength microstructures and continuous phase structures, a diffraction efficiency close to 100% can be achieved. The former processing methods include etching and thin film deposition, the latter include laser beam direct writing, electron beam direct writing and diamond turning, in addition, there are new production methods such as excimer laser processing and grayscale mask method. For occasions with low precision requirements, a two-step structure and wet etching processing can be selected; for occasions with general precision requirements, a two-step or 8-step or less structure, dry etching or thin film deposition processing can be selected; for occasions with high precision requirements, multi-step and continuous phase structure, laser beam direct writing, electron beam direct writing and diamond turning processing can be selected; for occasions with very high precision requirements (such as space satellite laser reflectors), a continuous phase structure, excimer laser processing with strictly controlled pulse number and grayscale mask method (no overlay alignment error, short cycle, low cost) can be selected for processing, and the positioning accuracy should be controlled below 100nm to ensure the contour accuracy, feature size and other device manufacturing factors of the phase film.

[0061] In this embodiment, the manufacturing process of the beam shaping element includes phase design, template manufacturing (the direct writing method does not require template manufacturing, and etching into sheets. The phase design can be programmed and optimized according to the shaping requirements using mature commercial computer optical software; the phase etching parameters (depth) and size are related to the detection laser wavelength and the light field pattern distribution (divergence angle) required by the target, and can be designed according to specific requirements. At the same time, the phase design is related to the surface etching shape, but both are symmetrical relative to the center.

[0062] See also Figure 4 and Figure 5 As shown, for high-speed detection targets, the phase structure added by the technical solution of the present invention can shape the far-field energy distribution of the traditional reflector with deviation (outside the central Airy disk, surrounded by 6 sub-annular light spots) into an annular light field, thereby improving the energy density and receiving efficiency of the target receiving light field; typical uses include space satellite positioning with optical cooperation targets, space vehicle formation, optoelectronic docking of space stations, high-speed aircraft detection, etc.

[0063] See also Figure 6 and Figure 7As shown, for low-speed detection targets, the addition of a phase structure through the technical solution of the present invention can shape the far-field energy distribution (central Airy disk) of the traditional unbiased reflector into a flat-top light field, thereby improving the energy density and receiving efficiency of the target receiving light field; typical uses include carrier-based aircraft and drone landing with optical cooperation targets, low-speed aircraft tracking and ranging, lasers with corner cube prisms, etc.

[0064] In summary, the technical solution of the embodiment of the present invention is applicable to an optoelectronic laser ranging and positioning system with a cooperative target. It utilizes the principle of laser optical monochromatic diffraction interference synthesis, and adds a specific centrally symmetrical subwavelength annular phase structure that meets the requirements and has a certain regularity on the surface (or position) of the laser reflector through micro-machining methods such as etching and laser beam direct writing to achieve high control and concentration of the reflected light field energy. This technical solution can greatly improve the reflection efficiency of the cooperative target, and its products can be applied to various ranging fields such as aviation and aerospace, especially for space-borne aircraft laser positioning and space station rendezvous and docking without atmospheric interference, which can greatly improve the reflection energy and effective distance of the target, reduce the power consumption, volume and weight of the detection equipment, and the effect is more obvious.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A spatial optical laser reflector, characterized in that: include: The three right-angle reflection surface reflection structure is used to accurately return the incident laser beam along the original optical path direction; The diffraction phase shaping structure is a series of periodic sub-wavelength concentric annular gratings, which are arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure, and are used to interfere and shape the laser beam reflected by the three-right-angle reflection surface reflection structure through its surface grating to form a light spot that meets the requirements at the target receiving position; The three right-angle reflective surface reflective structure is a solid reflector or a hollow reflector, wherein the solid reflector includes three mutually perpendicular reflective surfaces and an incident and exiting surface, is a tetrahedral conical prism, and has a spatial directional emission characteristic; the hollow reflector is composed of three mutually perpendicular reflective surfaces; When the three-right-angle reflection surface reflection structure is a solid reflector, the diffraction phase shaping structure is a series of periodic sub-wavelength concentric annular gratings engraved or etched on the incident and exit surfaces of the three-right-angle reflection surface reflection structure; or, the diffraction phase shaping structure is a phase sheet of a plane arranged at the incident and exit surfaces of the three-right-angle reflection surface reflection structure, and a series of periodic sub-wavelength annular fan gratings are engraved or etched on the incident surface of the phase sheet; When the three-right-angle reflection surface reflection structure is a hollow reflector, the diffraction phase shaping structure is a phase sheet of a plane arranged at the incident surface position of the three-right-angle reflection surface reflection structure, and the incident surface of the phase sheet is engraved or etched with a series of periodic sub-wavelength annular fan gratings; The series of periodic parameters specifically include: grating line number, groove depth, shape, and period; The materials of the three right-angle reflective surface reflective structure include: glass, engineering plastics, and metal, wherein the material of the solid reflector is fused quartz glass when used in a space environment; The right-angle reflection surface or reflection surface film layer profile accuracy of the three-right-angle reflection surface reflection structure is at least 1 / 10λ; The diffraction phase shaping structure specifically includes: two-step, multi-step, continuous phase binary optical element structure forms and sub-wavelength microstructure and continuous phase structure; The phase photo is arranged on the incident and exit surfaces of the three-right-angle reflection surface reflection structure by means of mechanical housing connection or gluing.

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