Dual-band laser ranging optical structure

Abstract

The invention relates to the technical field of space target laser ranging, in particular to a dual-band laser ranging optical structure, which is characterized in that a dual-band ranging unit is arranged on a rear-end light path of a first image plane of a Cassegrain system, and a target light beam is divided into visible light and short-wave infrared light by using a first spectroscope; the visible light is split into a beam of light with the wave band of 532 nm and a beam of mixed light with the wave band of 532 nm and the wave band of 600-900 nm through a second spectroscope; the laser sensors are respectively used for laser ranging, beam monitoring and detection imaging; the short-wave infrared is converted into a beam of 1064nm wave band light and a beam of mixed light of the 1064nm wave band and the 1100nm-1700nm wave band through a third spectroscope; the device is respectively used for laser ranging, beam monitoring and detection imaging. According to the invention, a dual-wavelength laser ranging function, laser beam monitoring, visible light detection imaging and short-wave infrared detection imaging are realized, and the problems that a laser ranging telescope with the aperture of more than 500mm cannot realize multi-wavelength detection and an optical telescope needs to be independently equipped for imaging detection and beam monitoring are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of space target laser ranging, and in particular relates to a dual-band laser ranging optical structure. Background Art

[0002] Space target laser ranging technology is an observation technology that uses laser pulses to measure the distance from the ground observation station to the space target. It is the technical means with the highest ranging accuracy in the entire detection system and can effectively improve the upper limit of the ranging data accuracy of space targets. By utilizing the high-precision characteristics of the laser ranging telescope, dangerous events of space targets can be precisely monitored to support the final risk assessment and provide support for decision-making on dangerous events. The ranging accuracy is greatly affected by the aperture of the laser ranging telescope, that is, the larger the aperture of the laser ranging telescope, the stronger the ability to receive echo photons. Therefore, as the requirements for the ranging accuracy of space targets increase, the aperture of the laser ranging telescope is also getting larger.

[0003] Due to the limitation of optical element material preparation, currently all large-aperture laser ranging telescopes with an aperture of more than 500mm are single-wavelength laser ranging optical systems, and cannot take into account multiple spectral imaging detection and laser beam monitoring functions. They need to be equipped with separate optical telescopes for imaging detection or laser beam monitoring. Therefore, it is urgent to design and implement dual-wavelength or even multi-wavelength laser ranging for laser ranging telescopes with an aperture of more than 500mm. Summary of the invention

[0004] In view of this, the present invention aims to provide a dual-band laser ranging optical structure for an aperture of 500mm or more, which realizes the dual-wavelength laser ranging function while also having visible light and short-wave infrared imaging detection and laser beam monitoring functions, thereby solving the problem that the existing large-aperture laser ranging telescope can only realize single-wavelength detection and needs to be equipped with a separate optical telescope for imaging detection or laser beam monitoring.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows: The invention provides a dual-band laser ranging optical structure, comprising: a main optical system for acquiring a target light beam, and a ranging unit; The distance measuring unit comprises: a first beam splitter, which is used to split the target light beam into visible light and short-wave infrared; A second spectroscope is provided on the propagation optical path of the visible light, and the second spectroscope is used to split the visible light into: a partial 532nm band light, and a mixed light of the remaining 532nm band and the 600nm-900nm band; wherein the partial 532nm band light is used for laser ranging, the remaining 532nm band in the mixed light of the remaining 532nm band and the 600nm-900nm band is used for beam monitoring, and the 600nm-900nm band is used for laser imaging; A third spectroscope is arranged on the propagation optical path of the short-wave infrared, and the third spectroscope is used to split the short-wave infrared into: a partial 1064nm band light, and a mixed light of the remaining 1064nm band and the 1100nm-1700nm band; wherein, the partial 1064nm band light is used for laser ranging, the remaining 1064nm band in the mixed light of the remaining 1064nm band and the 1100nm-1700nm band is used for beam monitoring, and the 1100nm-1700nm band is used for laser imaging.

[0006] Preferably, the primary optical system is a Cassegrain system, comprising a primary mirror and a secondary mirror, wherein the primary mirror is a parabola and the secondary mirror is a hyperbolic surface.

[0007] Preferably, the distance measuring unit is arranged on the rear end optical path of the first image plane of the main optical system.

[0008] Preferably, the distance measuring unit further includes a collimating lens group arranged in the front end optical path of the first beam splitter.

[0009] Preferably, the second beam splitter has a partial reflection and partial transmission effect on the 532nm band, and has a total reflection or total transmission effect on the 600nm-900nm band.

[0010] Preferably, the third beam splitter has a partial reflection and partial transmission effect on the 1064nm band, and has a total reflection or total transmission effect on the 1100nm-1700nm band.

[0011] Preferably, a first lens group for focusing the part of the 532nm band light and coupling it into the optical fiber for distance measurement is provided on the propagation optical path of the part of the 532nm band light; A second lens group and a third lens group are provided on the propagation optical path of the mixed light of the remaining 532nm band and the 600nm-900nm band for focusing the mixed light of the remaining 532nm band and the 600nm-900nm band, and the remaining 532nm band is used for beam monitoring, and the 600nm-900nm band is used for imaging the first field of view target.

[0012] Preferably, a fourth lens group is provided on the propagation optical path of the part of the 1064nm band light for focusing the part of the 1064nm band light and coupling it into the optical fiber for distance measurement; A fifth lens group and a sixth lens group are provided on the propagation optical path of the mixed light of the remaining 1064nm band and the 1100nm-1700nm band, which are used to focus the mixed light of the remaining 1064nm band and the 1100nm-1700nm band, and the remaining 1064nm band is used for beam monitoring, and the 1100nm-1700nm band is used for imaging the second field of view target.

[0013] Preferably, the collimating lens group has positive optical power and a focal length of 270 mm-290 mm; The first lens group has positive optical power and a focal length of 240mm-250mm; The second lens group has positive optical power and a focal length of 460mm-470mm; The third lens group has positive optical power and a focal length of 130 mm to 140 mm; The fourth lens group has positive power and a focal length of 195-205 mm; The fifth lens group has positive optical power and a focal length of 190 mm to 200 mm; The sixth lens group has positive optical power and a focal length of 110 mm to 130 mm.

[0014] Preferably, the collimating lens assembly is a cemented lens of a first lens and a second lens, wherein the refractive index of the first lens is and Abbe number satisfy: ; ; Refractive index of the second lens and Abbe number satisfy: ; ; The lenses in the first lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ; ; The second lens group includes at least five lenses made of different materials, and the refractive index of the first lens made of the second lens group is and Abbe number satisfy: ; ; The refractive index of the second lens made of the second lens group is and Abbe number Respectively meet: ; ; The refractive index of the third material lens in the second lens group and Abbe number Respectively meet: ; ; The refractive index of the fourth preparation material lens in the second lens group and Abbe number Respectively meet: ; ; The refractive index of the fifth material lens in the second lens group and Abbe number Respectively meet: ; ; The third lens group includes at least three lenses made of different materials, and the refractive index of the first lens made of the third lens group is and Abbe number satisfy: ; ; The refractive index of the second preparation material lens in the third lens group and Abbe number satisfy: ; ; The refractive index of the third lens made of the third lens group and Abbe number satisfy: ; ; The lenses in the fourth lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ; ; The fifth lens group includes at least three lenses made of different materials, and the refractive index of the first lens made of the material in the fifth lens group is and Abbe number satisfy: ; ; The refractive index of the second material lens in the fifth lens group and Abbe number satisfy: ; ; The refractive index of the lens made of the third material in the fifth lens group and Abbe number satisfy: ; ; The lenses in the sixth lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ; .

[0015] Compared with the prior art, the invention can achieve the following beneficial effects: The invention is based on a refractive-reflective hybrid optical system and utilizes a lens, a beam splitter and a reflector combination to perform multi-spectral functional applications, thereby realizing 532nm and 1064nm dual-wavelength laser ranging functions, 532nm and 1064nm laser beam monitoring, as well as detection imaging of a 20-minute field of view of visible light and a 10-minute field of view of short-wave infrared. The invention solves the problem that laser ranging telescopes with an aperture of more than 500mm cannot realize multi-wavelength detection and need to be equipped with an optical telescope separately for imaging detection and laser beam monitoring, thereby improving functional integration and structural compactness and realizing the expansion of the functions of the laser ranging optical system.

[0016] The present invention optimizes each lens group specially, and performs aberration correction by reasonably combining lenses, reflectors and dichroic mirrors. Since the whole system has a large field of view and a wide working band, a specific refractive index dispersion coefficient lens material combination is used to correct off-axis aberration and chromatic aberration, correcting the aberration and chromatic aberration of the visible light and short-wave infrared spectrum, and improving the imaging quality. In addition, the distance measuring unit is set at the rear end of the first image plane of the Cassegrain system, realizing the segmented design of the main optical system and the distance measuring optical path, avoiding mutual interference caused by the adjustment process, improving the convenience of the optical adjustment detection of the system, and the main optical system and the distance measuring optical path can be adjusted and detected separately at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 is a schematic diagram of an optical path of a dual-band laser ranging optical structure provided according to an embodiment of the present invention; Figure 2 Schematic diagram of the optical path of a distance measuring unit provided according to an embodiment of the present invention.

[0018] Reference numerals include: Main optical system A, primary mirror 1, secondary mirror 2, first reflecting mirror 3; Distance measuring unit B, collimating lens group 4, first dichroic mirror 5, second dichroic mirror 6, first lens group 7, second lens group 8, third lens group 9, second reflecting mirror 10, third dichroic mirror 11, fourth lens group 12, third reflecting mirror 13, fifth lens group 14, sixth lens group 15. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the invention clearer, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and do not constitute a limitation to the invention. Similar components in different embodiments use associated similar component numbers. In the following embodiments, many detailed descriptions are to enable the invention to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other components, materials, and methods. In some cases, some operations related to the invention are not shown or described in the specification, in order to avoid the core part of the invention being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0021] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0022] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0024] See also Figure 1 and Figure 2 In one embodiment of the present invention, a dual-band laser ranging optical structure is provided to solve the problem that currently large-aperture laser ranging telescopes with an aperture of more than 500 mm can only achieve single-wavelength laser ranging. Due to the constraints of optical material preparation technology, systems with an aperture of more than 500 mm only support laser ranging with a single wavelength (such as 532nm or 1064nm), and cannot take into account the dual-band applications of visible light and short-wave infrared. In addition, the existing system needs to be equipped with an additional independent telescope to achieve imaging detection or laser beam monitoring, resulting in a complex structure and low integration. Under the conditions of large field of view and wide band, the correction effect of off-axis aberration and chromatic aberration is limited, affecting the imaging quality. To solve the above problems, the embodiment of the present invention integrates and designs a dual-band ranging optical structure based on the traditional Cassegrain system. Specifically, the dual-band laser ranging optical structure is a large-aperture, multi-spectral, multi-terminal optical structure, which mainly includes a main optical system A and a ranging unit B; wherein the main optical system A is a classic Cassegrain optical structure, that is, it includes a primary mirror 1 and a secondary mirror 2, the primary mirror 1 is a parabola, and the secondary mirror 2 is a hyperbolic surface. The primary mirror 1 collects the light reflected from the target at infinity, and after being reflected by the primary mirror 1, the light is reflected again by the secondary mirror 2 and focused on the first reflector 3 near the focus of the primary mirror 1, and is reflected to the ranging unit B by the first reflector 3.

[0025] Considering the convenience of optical adjustment and detection of the system, the distance measuring unit B is designed after the first image plane of the main optical system A, so that the main optical system A and the distance measuring unit B can be adjusted and detected separately during the optical debugging process, and debugging interference between the two can be avoided. The distance measuring unit B includes a collimating lens group 4 and a first dichroic mirror 5 arranged along the incident propagation direction of the target light beam, as well as a subsequent visible light path and a short-wave infrared light path, wherein the collimating lens group 4 is used to collimate the target light beam collected by the main optical system A, and the target light beam is processed into a collimated light beam after passing through the collimating lens group 4, and then incident on the first dichroic mirror 5, and the first dichroic mirror 5 is used to split the collimated target light beam into visible light and short-wave infrared, and the visible light mainly includes 532nm band light for visible light ranging and 600nm-900nm band light for laser detection imaging; the short-wave infrared mainly includes 1064nm band light for infrared laser ranging and 1100nm-1700nm band light for laser detection imaging. To ensure optical efficiency, the first dichroic mirror 5 is designed to transmit the short-wave infrared spectrum and reflect the visible spectrum. The visible light and short-wave infrared are respectively injected into the subsequent visible light path and short-wave infrared light path.

[0026] In the optical path of the visible light band, a second dichroic mirror 6 is provided along the propagation optical path of the visible light. The second dichroic mirror 6 is designed to have a partial reflection and partial transmission effect on the 532nm band, and a full reflection or full transmission effect on the 600nm-900nm band, so as to achieve spectral splitting. In the embodiment of the present invention, the second dichroic mirror 6 reflects 60% of the 532nm wavelength light in the visible spectrum band to the first lens group 7 to achieve laser ranging; after transmitting the remaining 40% of the 532nm wavelength light and all the 600nm-900nm band light, it continues to be emitted to the second lens group 8 and the third lens group 9 and other target imaging and beam monitoring optical paths.

[0027] After passing through the second beam splitter 6, the light is divided into two beams, one of which is 60% of the 532nm wavelength light, which is directed to the first lens group 7. The first lens group 7 focuses the laser echo beam and focuses it into a beam with a numerical aperture NA=0.22, and couples it into a multimode optical fiber to facilitate the subsequent visible light laser ranging. The other mixed light composed of the remaining 532nm band light and the 600nm-900nm band light is directed to the second lens group 8 and the third lens group 9. The second lens group 8 and the third lens group 9 are used to perform secondary beam reduction, collimation and focusing on the mixed light composed of the 532nm band light and the 600nm-900nm band light. The purpose of the secondary beam reduction and collimation is to place the field of view aperture and filter. The second lens group 8 and the third lens group 9 focus the 532nm band light and the 600nm-900nm band light into a beam with a focal length of f=3500mm, realizing visible light imaging and optical monitoring of the target field of view of 20 minutes.

[0028] In the short-wave infrared light band optical path, a second reflector 10, a third dichroic mirror 11 and a third reflector 13 are provided along the short-wave infrared propagation optical path, wherein the second reflector 10 and the third reflector 13 are both used to change the propagation direction of the light beam, rationalize the design of the optical path, and reduce the overall size of the system. After being reflected by the second reflector 10, the short-wave infrared is directed to the third dichroic mirror 11, which is designed to have partial reflection and partial transmission effects on the 1064nm band, and full reflection or full transmission effects on the 1100nm-1700nm band, so as to achieve spectral splitting. In the embodiment of the present invention, the third dichroic mirror 11 reflects 60% of the 1064nm wavelength light in the short-wave infrared spectrum to the fourth lens group 12 to achieve laser ranging in the infrared band; after transmitting the remaining 40% of the 1064nm wavelength light and all the 1100nm-1700nm band light, it continues to be emitted to the third reflector 13, and the third reflector 13 reflects this part of the light to the fifth lens group 14 and the sixth lens group 15 for target imaging and beam monitoring in the infrared band.

[0029] After passing through the third dichroic mirror 11, the two beams of light are separated, one of which is 60% of the 1064nm wavelength light, which is directed to the fourth lens group 12. The fourth lens group 12 focuses the laser echo beam and focuses it into a beam with a numerical aperture NA=0.22, and couples it into a multimode optical fiber to facilitate subsequent laser ranging in the infrared band. The other mixed light composed of the remaining 1064nm band light and the 1100nm-1700nm band light is directed to the third reflector 13, and the third reflector 13 reflects this part of the light to the fifth lens group 14 and the sixth lens group 15. The fifth lens group 14 and the sixth lens group 15 are used to focus the mixed light composed of the remaining 1064nm band light and the 1100nm-1700nm band light, focusing it into a beam with a focal length of f=4200mm, so as to achieve infrared band imaging and optical monitoring of the target field of view of 10 minutes.

[0030] The dual-band laser ranging optical structure obtained by the above design can achieve coverage of the visible spectrum and short-wave infrared spectrum for telescopes with an aperture of 500mm or more, and can achieve infrared and visible dual-band laser ranging. The field of view of visible light imaging and monitoring can reach 20 minutes, and the field of view of short-wave infrared imaging and monitoring can reach 10 minutes, meeting the current demand for 8 minutes of visible light optical field of view and 5 minutes of short-wave infrared optical field of view, and the imaging effect is good. In the case of dual-band ranging, there is no need to use additional equipment to achieve visible light and short-wave infrared imaging detection and laser beam monitoring functions. It can be directly installed on the laser ranging telescope machine and rotated with the telescope to achieve dual-band ranging and imaging monitoring. It has the characteristics of compact structure, simple integration, and excellent image quality.

[0031] The dual-band laser ranging optical structure of the embodiment of the present invention is composed of lenses, reflectors and dichroic mirrors, etc. It is a refractive-reflective hybrid optical system. Since the entire system has a large field of view and a wide working band, it is necessary to reasonably combine the lenses, reflectors and dichroic mirrors for aberration correction, and use a specific refractive index dispersion coefficient lens material combination to correct off-axis aberration and chromatic aberration. Specifically, after a lot of creative work, the following specific parameter data were obtained: First, in the embodiment of the present invention, the first dichroic mirror 5, the second dichroic mirror 6 and the third dichroic mirror 11 are all double-sided high-precision flat crystals, and are 45° to the system optical axis. The collimator lens group 4, the first lens group 7, the second lens group 8, the third lens group 9, the fourth lens group 12, the fifth lens group 14 and the sixth lens group 15 are all spherical lenses with optical focal length, and the line connecting the spherical centers of all lenses coincides with the system optical axis. Among them, the collimator lens group 4 has positive optical focal length and is a cemented lens composed of a first lens and a second lens. Both surfaces and the cemented interface are spherical surfaces. The line connecting the spherical centers of the front and rear surfaces coincides with the system optical axis, and its focal length is 270mm-290mm. In order to solve the chromatic aberration problem, the collimator lens group 4 uses two different brands of optical materials. It should be noted that here it means that the two lenses are made of two different materials, not that each lens is made of two different mixed materials. The refractive index of the first lens and Abbe number satisfy: ; ; Refractive index of the second lens and Abbe number satisfy: ; .

[0032] The first lens group 7 is of positive power and consists of three spherical lenses. The lines connecting the centers of all spheres coincide with the optical axis of the system, and the focal length is 240mm-250mm. The materials of the lenses in the first lens group 7 are the same, including only one brand of optical material. The refractive index of the material used to prepare it is and Abbe number All meet the following requirements: ; .

[0033] The second lens group 8 is of positive power and consists of 5 spherical lenses. The connecting line of all spherical centers coincides with the optical axis of the system, and its focal length is 460mm-470mm. The materials of each lens in the second lens group 8 are different, including lenses made of 5 different brands of optical materials. The refractive index of these 5 different brands of optical materials is and Abbe number Respectively meet: Refractive index of the first preparation material lens in the second lens group 8 and Abbe number satisfy: ; .

[0034] Refractive index of the second preparation material lens in the second lens group 8 and Abbe number Respectively meet: ; .

[0035] Refractive index of the third material lens in the second lens group 8 and Abbe number Respectively meet: ; .

[0036] Refractive index of the fourth preparation material lens in the second lens group 8 and Abbe number Respectively meet: ; .

[0037] Refractive index of the fifth material lens in the second lens group 8 and Abbe number Respectively meet: ; .

[0038] The third lens group 9 is of positive power and consists of three spherical lenses. The lines connecting the centers of all spheres coincide with the optical axis of the system, and the focal length is 130mm-140mm. The materials of the lenses in the third lens group 9 are different, including lenses made of three different brands of optical materials. The refractive index of these three different brands of optical materials is and Abbe number Respectively meet: Refractive index of the first preparation material lens in the third lens group 9 and Abbe number satisfy: ; .

[0039] Refractive index of the second preparation material lens in the third lens group 9 and Abbe number satisfy: ; .

[0040] Refractive index of the third preparation material lens in the third lens group 9 and Abbe number satisfy: ; .

[0041] The fourth lens group 12 has positive focal power and is composed of three spherical lenses. The connecting line of all spherical centers coincides with the optical axis of the system, and its focal length is 195-205mm. The materials of the lenses in the fourth lens group 12 are the same, and only one lens made of a different brand of optical material is included. The refractive index of this different brand of optical material is and Abbe number satisfy: ; .

[0042] The fifth lens group 14 has positive focal power and is composed of three spherical lenses. The lines connecting the centers of all spheres coincide with the optical axis of the system, and the focal length is 190mm-200mm. The materials of the lenses in the fifth lens group 14 are different, including lenses made of three different brands of optical materials. The refractive index of these three different brands of optical materials is and Abbe number Respectively meet: Refractive index of the first material lens in the fifth lens group 14 and Abbe number satisfy: ; .

[0043] Refractive index of the second preparation material lens in the fifth lens group 14 and Abbe number satisfy: ; .

[0044] Refractive index of the third material lens in the fifth lens group 14 and Abbe number satisfy: ; .

[0045] The sixth lens group 15 has positive focal power and is composed of two spherical lenses. The lines connecting the centers of all spheres coincide with the optical axis of the system, and the focal length is 110mm-130mm. The lenses in the sixth lens group 15 are made of the same material and only include lenses made of one optical material of different grades. The refractive index of the optical material of different grades is and Abbe number satisfy: ; .

[0046] The dual-band laser ranging optical structure with an aperture of more than 500mm obtained according to the above parameters and optical structure design realizes the dual-wavelength laser ranging function, and also has the functions of visible light and short-wave infrared imaging detection and laser beam monitoring, which solves the disadvantages of existing large-aperture laser ranging telescopes that can only realize single-wavelength detection and need to be equipped with additional optical telescopes for imaging detection or laser beam monitoring.

[0047] In short, the above description is only a preferred embodiment of this specification and is not intended to limit the protection scope of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included in the protection scope of this specification.

[0048] The systems, devices, modules or units described in one or more of the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0049] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0050] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0051] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A dual-band laser ranging optical structure, characterized in that: include: A main optical system for acquiring a target beam, and a distance measuring unit; The distance measuring unit comprises: a first beam splitter, which is used to split the target light beam into visible light and short-wave infrared; A second spectroscope is provided on the propagation optical path of the visible light, and the second spectroscope is used to split the visible light into: a partial 532nm band light, and a mixed light of the remaining 532nm band and the 600nm-900nm band; wherein the partial 532nm band light is used for laser ranging, and the mixed light of the remaining 532nm band and the 600nm-900nm band is used for beam monitoring and laser imaging; A third spectroscope is arranged on the propagation optical path of the short-wave infrared, and the third spectroscope is used to split the short-wave infrared into: a partial 1064nm band light, and a mixed light of the remaining 1064nm band and the 1100nm-1700nm band; wherein, the partial 1064nm band light is used for laser ranging, and the mixed light of the remaining 1064nm band and the 1100nm-1700nm band is used for beam monitoring and laser imaging.

2. The dual-band laser ranging optical structure according to claim 1, characterized in that: The primary optical system is a Cassegrain system, comprising a primary mirror and a secondary mirror, wherein the primary mirror is a parabola and the secondary mirror is a hyperbolic surface.

3. The dual-band laser ranging optical structure according to claim 2, characterized in that: The distance measuring unit is arranged on the rear optical path of the first image plane of the main optical system.

4. The dual-band laser ranging optical structure according to claim 1, characterized in that: The distance measuring unit further comprises a collimating lens group arranged in the front optical path of the first beam splitter.

5. The dual-band laser ranging optical structure according to any one of claims 1 to 4, characterized in that: The second beam splitter has a partial reflection and partial transmission effect on the 532nm band, and has a total reflection or total transmission effect on the 600nm-900nm band.

6. The dual-band laser ranging optical structure according to any one of claims 1 to 4, characterized in that: The third beam splitter has a partial reflection and partial transmission effect on the 1064nm band, and has a total reflection or total transmission effect on the 1100nm-1700nm band.

7. The dual-band laser ranging optical structure according to claim 4, characterized in that: A first lens group is provided on the propagation optical path of the part of the 532nm band light for focusing the part of the 532nm band light and coupling it into the optical fiber for distance measurement; A second lens group and a third lens group are provided on the propagation optical path of the mixed light of the remaining 532nm band and the 600nm-900nm band for focusing the mixed light of the remaining 532nm band and the 600nm-900nm band, and the remaining 532nm band is used for beam monitoring, and the 600nm-900nm band is used for imaging the first field of view target.

8. The dual-band laser ranging optical structure according to claim 7, characterized in that: A fourth lens group is provided on the propagation optical path of the part of the 1064nm band light for focusing the part of the 1064nm band light and coupling it into the optical fiber for distance measurement; A fifth lens group and a sixth lens group are provided on the propagation optical path of the mixed light of the remaining 1064nm band and the 1100nm-1700nm band, which are used to focus the mixed light of the remaining 1064nm band and the 1100nm-1700nm band, and the remaining 1064nm band is used for beam monitoring, and the 1100nm-1700nm band is used for imaging the second field of view target.

9. The dual-band laser ranging optical structure according to claim 8, characterized in that: The collimator lens group has positive focal power and a focal length of 270mm-290mm; The first lens group has positive optical power and a focal length of 240mm-250mm; The second lens group has positive optical power and a focal length of 460mm-470mm; The third lens group has positive optical power and a focal length of 130 mm to 140 mm; The fourth lens group has positive optical power and a focal length of 195-205 mm; The fifth lens group has positive optical power and a focal length of 190 mm to 200 mm; The sixth lens group has positive optical power and a focal length of 110 mm to 130 mm.

10. The dual-band laser ranging optical structure according to claim 9, characterized in that: The collimating lens assembly is a cemented lens of a first lens and a second lens, wherein the refractive index of the first lens is and Abbe number satisfy: ； ； Refractive index of the second lens and Abbe number satisfy: ； ； The lenses in the first lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ； ； The second lens group includes at least five lenses made of different materials, and the refractive index of the first lens made of the second lens group is and Abbe number satisfy: ； ； The refractive index of the second lens made of the second lens group is and Abbe number Respectively meet: ； ； The refractive index of the third material lens in the second lens group and Abbe number Respectively meet: ； ； The refractive index of the fourth preparation material lens in the second lens group and Abbe number Respectively meet: ； ； The refractive index of the fifth material lens in the second lens group and Abbe number Respectively meet: ； ； The third lens group includes at least three lenses made of different materials, and the refractive index of the first lens made of the third lens group is and Abbe number satisfy: ； ； The refractive index of the second preparation material lens in the third lens group and Abbe number satisfy: ； ； The refractive index of the third lens made of the third lens group and Abbe number satisfy: ； ； The lenses in the fourth lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ； ； The fifth lens group includes at least three lenses made of different materials, and the refractive index of the first lens made of the material in the fifth lens group is and Abbe number satisfy: ； ； The refractive index of the second material lens in the fifth lens group and Abbe number satisfy: ； ； The refractive index of the lens made of the third material in the fifth lens group and Abbe number satisfy: ； ； The lenses in the sixth lens group are made of the same material, and the refractive index of the material is and Abbe number All meet the following requirements: ； 。

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