Large-aperture three-waveband integrated optical system

Abstract

The invention discloses a large-aperture three-waveband integrated optical system, and solves the technical problem that an existing multi-waveband imaging system is large in size and weight. The optical system comprises a main reflector, a first spectrum spectroscope, a first folding-axis mirror, a second folding-axis mirror, a second spectrum spectroscope, a visible light optical unit, a short-wave optical unit, a third folding-axis mirror and a medium-wave optical unit. Wherein the main reflecting mirror, the first spectrum spectroscope, the first folding-axis mirror, the second folding-axis mirror, the second spectrum spectroscope and the visible light optical unit form a visible light optical system for receiving visible light beams; the main reflecting mirror, the first spectrum spectroscope, the first folding-axis mirror, the second folding-axis mirror, the second spectrum spectroscope and the short-wave optical unit form a short-wave infrared optical system for receiving short-wave infrared light beams; the main reflector, the first spectrum spectroscope, the third folding-axis mirror and the medium-wave optical unit form a medium-wave infrared optical system to receive medium-wave infrared beams. The optical system adopts a modular design and is high in integration level.

Description

Technical Field

[0001] The present invention relates to a three-band integrated optical system, in particular to a large-aperture visible light / short-wave infrared / medium-wave infrared three-band integrated optical system. Background Art

[0002] With the continuous advancement of target camouflage and stealth technology, the information that can be detected by traditional single-band equipment can no longer meet the needs of target detection. In order to meet the requirements of all-day observation, it is necessary to adopt a multi-band imaging system to obtain target information.

[0003] Currently, visible light systems rely primarily on sunlight reflected from the target for imaging, significantly reducing or even rendering them inoperable at night or in low-light conditions. Furthermore, visible light systems are susceptible to environmental interference, making observation difficult in fog or obstructions. Infrared systems, on the other hand, rely primarily on the target's own radiation for detection and imaging. They can observe both day and night, and even in poor visibility conditions. Compared to visible light systems, infrared systems can more safely and covertly identify targets, including those that are camouflaged.

[0004] As the aperture of the system continues to increase, the traditional three independent imaging systems have gradually exposed the shortcomings of being large and heavy, which does not meet the development needs of miniaturization and lightweight systems. Therefore, it is necessary to design an optical system that combines visible light, short-wave infrared, and medium-wave infrared to achieve high visible light resolution and high infrared sensitivity. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem of large volume and weight of existing multi-band imaging systems and to provide a large-aperture three-band integrated optical system.

[0006] To achieve the above objectives, the technical solutions provided by the present invention are:

[0007] A large-aperture, three-band integrated optical system, which is special in that:

[0008] It includes a main reflector, a first spectrum splitter, a first folding mirror, a second folding mirror, a second spectrum splitter, a visible light optical unit, a short wave optical unit, a third folding mirror and a medium wave optical unit;

[0009] The first spectrum splitter is located on the reflection light path of the main reflector. The light beam from the target object is reflected by the main reflector and split into two paths by the first spectrum splitter. One path reflects the visible light beam and the short-wave infrared light beam after passing through the first spectrum splitter, and the other path transmits the medium-wave infrared light beam after passing through the first spectrum splitter.

[0010] The first folding mirror, the second folding mirror, and the second spectrum beam splitter are sequentially arranged along the reflected light path of the first spectrum beam splitter, the visible light optical unit is located on the reflected light path of the second spectrum beam splitter, and the short-wave optical unit is located on the transmitted light path of the second spectrum beam splitter; the third folding mirror and the medium-wave optical unit are sequentially arranged along the transmitted light path of the first spectrum beam splitter;

[0011] The main reflector, the first spectrum splitter, the first folding mirror, the second folding mirror, the second spectrum splitter and the visible light optical unit together constitute a visible light optical system for receiving a visible light beam;

[0012] The main reflector, the first spectrum splitter, the first folding mirror, the second folding mirror, the second spectrum splitter and the short-wave optical unit together constitute a short-wave infrared optical system for receiving a short-wave infrared light beam;

[0013] The main reflector, the first spectrum splitter, the third folding mirror and the medium-wave optical unit together constitute a medium-wave infrared optical system for receiving a medium-wave infrared light beam.

[0014] Furthermore, the visible light optical unit includes a visible light collimating lens group, a visible light short-focus objective lens group, and a visible light long-focus objective lens group arranged in sequence along the optical path; wherein the main reflector, the first spectral beam splitter, the first folding mirror, the second folding mirror, the second spectral beam splitter, the visible light collimating lens group, and the visible light short-focus objective lens group together constitute a visible light short-focus optical system; the main reflector, the first spectral beam splitter, the first folding mirror, the second folding mirror, the second spectral beam splitter, the visible light collimating lens group, and the visible light long-focus objective lens group together constitute a visible light long-focus optical system;

[0015] The short-wave optical unit includes a short-wave collimator group, a short-wave short-focus objective lens group, and a short-wavelength focus objective lens group arranged in sequence along the optical path; wherein the main reflector, the first spectrum beam splitter, the first folding mirror, the second folding mirror, the second spectrum beam splitter, the short-wave collimator group, and the short-wavelength short-focus objective lens group together constitute a short-wavelength short-focus infrared optical system; the main reflector, the first spectrum beam splitter, the first folding mirror, the second folding mirror, the second spectrum beam splitter, the short-wave collimator group, and the short-wavelength focus objective lens group together constitute a short-wavelength focus infrared optical system;

[0016] The medium-wave optical unit comprises a medium-wave infrared lens group and a projection lens group which are sequentially arranged along the optical path.

[0017] Furthermore, the visible light collimating mirror group includes a first collimating mirror, a second collimating mirror, a fourth folding mirror, a third collimating mirror, a fourth collimating mirror, a fifth collimating mirror, a sixth collimating mirror, a seventh collimating mirror, and an eighth collimating mirror, which are sequentially arranged along the reflected light path of the second spectrum splitter;

[0018] Among them, the first collimator is a meniscus heavy flint lens with negative focal power and convex toward the object side; the second collimator is a biconvex optical crystal with positive focal power; the fourth folding mirror is a plane reflecting mirror; the third collimator is a meniscus heavy flint lens with negative focal power and convex toward the object side; the fourth collimator is a biconcave light crown lens with negative focal power; the fifth collimator is a biconvex heavy phosphorus crown lens with positive focal power; the sixth collimator is a meniscus heavy flint lens with negative focal power and convex toward the image side; the seventh collimator is a meniscus heavy phosphorus crown lens with positive focal power and convex toward the image side; the eighth collimator is a meniscus heavy flint lens with positive focal power and convex toward the image side;

[0019] The visible light short-focus objective lens group includes a first short-focus lens, a second short-focus lens, a third short-focus lens, a fourth short-focus lens, a fifth short-focus lens, a sixth short-focus lens, and a seventh short-focus lens arranged in sequence along the optical path;

[0020] Among them, the first short-focus lens is a meniscus heavy flint lens with negative focal power and convex toward the image side; the second short-focus lens is a positive focal power biconvex fluorine crown lens; the third short-focus lens is a negative focal power biconcave light crown lens; the fourth short-focus lens is a positive focal power biconvex optical crystal; the fifth short-focus lens is a meniscus heavy phosphorus crown lens with negative focal power and convex toward the image side; the sixth short-focus lens is a positive focal power meniscus fluorine crown lens with positive focal power and convex toward the object side; the seventh short-focus lens is a meniscus heavy flint lens with negative focal power and convex toward the object side;

[0021] The visible light telephoto objective lens group includes a first telephoto lens, a second telephoto lens, a third telephoto lens, a fourth telephoto lens, and a fifth telephoto lens;

[0022] Among them, the first telephoto lens is a double convex optical crystal with positive focal power; the second telephoto lens is a meniscus light crown lens with negative focal power convex toward the image side; the third telephoto lens is a meniscus heavy flint lens with negative focal power convex toward the image side; the fourth telephoto lens is a meniscus heavy phosphorus crown lens with negative focal power convex toward the object side; the fifth telephoto lens is a meniscus heavy phosphorus crown lens with positive focal power convex toward the object side.

[0023] Furthermore, the visible light optical unit adopts an internal focusing mode, which is achieved by axially moving a focusing lens group consisting of a third collimating lens, a fourth collimating lens, and a fifth collimating lens.

[0024] Furthermore, the short-wave collimator group includes a first short-wave collimator, a fifth folding axis mirror, a second short-wave collimator, a third short-wave collimator, a fourth short-wave collimator, a fifth short-wave collimator, a sixth short-wave collimator, a sixth folding axis mirror and a seventh short-wave collimator, which are sequentially arranged along the transmission light path of the first spectrum splitter.

[0025] Among them, the first short-wave collimator is a positive-power biconvex heavy flint lens; the fifth folding mirror is a plane reflector; the second short-wave collimator is a negative-power meniscus heavy flint lens convex toward the object side; the third short-wave collimator is a negative-power biconcave light crown lens; the fourth short-wave collimator is a positive-power biconvex heavy phosphorus crown lens; the fifth short-wave collimator is a negative-power meniscus heavy flint lens convex toward the image side; the sixth short-wave collimator is a positive-power meniscus heavy phosphorus crown lens convex toward the image side; the sixth folding mirror is a plane reflector; the seventh short-wave collimator is a positive-power biconvex heavy flint lens;

[0026] The short-wavelength short-focus objective lens group includes a first short-wavelength short-focus lens, a second short-wavelength short-focus lens, a third short-wavelength short-focus lens, a fourth short-wavelength short-focus lens, a fifth short-wavelength short-focus lens, a sixth short-wavelength short-focus lens, and a seventh short-wavelength short-focus lens, which are sequentially arranged along the optical path;

[0027] Among them, the first short-wavelength short-focus lens is a meniscus heavy flint lens with negative focal power convex toward the image side; the second short-wavelength short-focus lens is a meniscus fluorine crown lens with positive focal power convex toward the object side; the third short-wavelength short-focus lens is a meniscus light crown lens with negative focal power convex toward the object side; the fourth short-wavelength short-focus lens is a positive focal power biconvex optical crystal; the fifth short-wavelength short-focus lens is a meniscus heavy flint lens with negative focal power convex toward the image side; the sixth short-wavelength short-focus lens is a positive focal power biconvex heavy phosphorus crown lens; the seventh short-wavelength short-focus lens is a meniscus heavy flint lens with negative focal power convex toward the object side;

[0028] The short-wavelength focal lens group includes a first short-wavelength focal lens, a second short-wavelength focal lens, a third short-wavelength focal lens, a fourth short-wavelength focal lens and a fifth short-wavelength focal lens arranged in sequence along the optical path;

[0029] Among them, the first short-wavelength focal lens is a positive-power biconvex heavy phosphor crown lens; the second short-wavelength focal lens is a negative-power biconcave light crown lens; the third short-wavelength focal lens is a negative-power meniscus heavy flint lens convex toward the object; the fourth short-wavelength focal lens is a positive-power biconvex fluorine crown lens; the fifth short-wavelength focal lens is a negative-power meniscus heavy phosphor crown lens convex toward the object.

[0030] Furthermore, the medium-wave infrared mirror group includes a first infrared mirror, a seventh folding mirror, a second infrared mirror, a third infrared mirror, and a fourth infrared mirror, which are sequentially arranged along the reflection light path of the third folding mirror;

[0031] The first infrared mirror is a positive-power ZnS meniscus lens convex toward the image side; the seventh folding mirror is a plane reflector; the second infrared mirror is a positive-power Germanium meniscus lens convex toward the object side; the third infrared mirror is a negative-power Germanium meniscus lens convex toward the object side; the fourth infrared mirror is a positive-power Germanium meniscus lens convex toward the object side;

[0032] The projection lens group includes a fifth infrared mirror, a sixth infrared mirror, and a seventh infrared mirror arranged in sequence along the optical path; wherein the fifth infrared mirror is a meniscus ZnS lens with negative optical power and convex toward the image side; the sixth infrared mirror is a meniscus germanium lens with negative optical power and convex toward the object side; and the seventh infrared mirror is a biconvex silicon lens with positive optical power.

[0033] Furthermore, the main reflector is a total reflector, and its surface shape is a parabola;

[0034] The first spectrum spectroscope is a negative-power, convex-object-facing meniscus germanium lens. The light incident surface of the first spectrum spectroscope is defined as its front surface, and the other surface is defined as its rear surface. The front surface is a hyperbolic surface coated with a spectrum spectroscope coating for reflecting visible light and short-wave infrared light and transmitting medium-wave infrared light. The rear surface is a spherical surface coated with a multi-layer antireflection coating for transmitting medium-wave infrared light.

[0035] The second spectrum beam splitter is a cube without optical power, and a beam splitting film is coated on the beam splitting surface, which is used to reflect visible light and transmit short-wave infrared light.

[0036] Furthermore, the second spectrum splitter is made of quartz.

[0037] Furthermore, a first variable iris is provided between the eighth collimating lens and the first short-focus lens or the first long-focus lens.

[0038] Furthermore, a second variable iris is provided between the seventh short-wave collimating lens and the first short-wave short-focus lens or the first short-wavelength short-focus lens;

[0039] The light output ends of the seventh short-wavelength short-focus lens and the fifth short-wavelength short-focus lens are respectively provided with attenuation plates.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] 1. The present invention comprises a primary reflector, a first spectral beam splitter, a first folding mirror, a second folding mirror, a second spectral beam splitter, and a visible light optical unit, which together form a visible light optical system for receiving visible light beams. The primary reflector, a first spectral beam splitter, a first folding mirror, a second folding mirror, a second spectral beam splitter, and a short-wave optical unit, which together form a short-wave infrared optical system for receiving short-wave infrared beams. The primary reflector, a first spectral beam splitter, a third folding mirror, and a medium-wave optical unit, together form a medium-wave infrared optical system for receiving medium-wave infrared beams. This constitutes a three-band integrated optical system in which visible light, short-wave infrared, and medium-wave infrared share a single primary optical system. The present invention employs a modular design, enabling independent detection of each component, resulting in a high degree of overall integration of the optical system and a reduction in system volume and weight.

[0042] 2. The present invention adopts the form of a first spectrum spectroscope for primary spectrometry and a second spectrum spectroscope for secondary spectrometry, thereby avoiding the astigmatism introduced by placing a parallel plate spectroscope at 45 degrees in the converging light path, thereby improving the imaging quality.

[0043] 3. The visible light optical system and the short-wave infrared optical system of the present invention can both achieve two-speed magnification, and the entire optical system has the advantages of reasonable and compact light splitting, high imaging quality, and the ability to be expanded into a four-band integrated optical system.

[0044] 4. The present invention adopts a modular structural design, which is conducive to the control of the assembly process, thereby effectively reducing the difficulty of system installation and adjustment, and ensuring high-quality imaging of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 2 is a light path diagram of a visible light short-focus optical system in an embodiment of the present invention.

[0046] Figure 2 2 is a light path diagram of a visible light telephoto optical system in an embodiment of the present invention.

[0047] Figure 3 2 is a light path diagram of the visible light collimating lens assembly in an embodiment of the present invention.

[0048] Figure 4 2 is a light path diagram of the visible light short-focus objective lens assembly in an embodiment of the present invention.

[0049] Figure 5 2 is a light path diagram of the visible light telephoto objective lens assembly in an embodiment of the present invention.

[0050] Figure 6 This is an optical path diagram of the short-wave infrared short-focus optical system in an embodiment of the present invention.

[0051] Figure 7 This is a light path diagram of the short-wave infrared telephoto optical system in an embodiment of the present invention.

[0052] Figure 8 2 is a light path diagram of the short-wave collimating lens group in an embodiment of the present invention.

[0053] Figure 9 2 is a light path diagram of the short-wavelength, short-focus objective lens assembly in an embodiment of the present invention.

[0054] Figure 10 2 is a light path diagram of the short-wavelength focus objective lens assembly in an embodiment of the present invention.

[0055] Figure 11 This is a light path diagram of the medium-wave infrared focal length optical system in an embodiment of the present invention.

[0056] Figure 12This is an MTF curve of an optical system with a spatial frequency of 50 lp / mm and a visible light short-focus of 2100 mm in an embodiment of the present invention.

[0057] Figure 13 This is an MTF curve of an optical system with a spatial frequency of 50 lp / mm and a visible light telephoto focus of 4200mm in an embodiment of the present invention.

[0058] Figure 14 This is an MTF curve of a short-wave infrared short-focus 1340mm optical system with a spatial frequency of 33lp / mm in an embodiment of the present invention.

[0059] Figure 15 This is an MTF curve of the short-wave infrared telephoto 2680mm optical system with a spatial frequency of 33lp / mm in an embodiment of the present invention.

[0060] Figure 16 This is an MTF curve of an optical system with a spatial frequency of 20lp / mm and a medium-wave infrared focal length of 2680mm in an embodiment of the present invention.

[0061] Figure 17 Graphs showing spherical aberration, field curvature, and distortion of a visible light short-focus 2100mm optical system in an embodiment of the present invention.

[0062] Figure 18 Graphs showing spherical aberration, field curvature, and distortion of a visible light telephoto 4200mm optical system in an embodiment of the present invention.

[0063] Figure 19 Graphs showing spherical aberration, field curvature, and distortion of a short-wave infrared short-focus 1340mm optical system in an embodiment of the present invention.

[0064] Figure 20 Graphs showing spherical aberration, field curvature, and distortion of a short-wave infrared telephoto 2680mm optical system in an embodiment of the present invention.

[0065] Figure 21 Graphs showing spherical aberration, field curvature, and distortion of a medium-wave infrared optical system with a focal length of 2680 mm in an embodiment of the present invention.

[0066] The reference numerals are as follows:

[0067] 1-main reflector, 2-first spectrum splitter, 3-first folding mirror, 4-second folding mirror, 5-second spectrum splitter, 6-third folding mirror, 7-first collimator, 8-second collimator, 9-fourth folding mirror, 10-third collimator, 11-fourth collimator, 12-fifth collimator, 13-sixth collimator, 14-seventh collimator, 15-eighth collimator, 16-first short focus mirror, 17 -Second short-focus mirror, 18-third short-focus mirror, 19-fourth short-focus mirror, 20-fifth short-focus mirror, 21-sixth short-focus mirror, 22-seventh short-focus mirror, 23-first long-focus mirror, 24-second long-focus mirror, 25-third long-focus mirror, 26-fourth long-focus mirror, 27-fifth long-focus mirror, 28-first short-wave collimator, 29-fifth folding mirror, 30-second short-wave collimator, 31-third short-wave collimator, 32 -Fourth shortwave collimator, 33-fifth shortwave collimator, 34-sixth shortwave collimator, 35-sixth folding mirror, 36-seventh shortwave collimator, 37-first shortwave short-focus mirror, 38-second shortwave short-focus mirror, 39-third shortwave short-focus mirror, 40-fourth shortwave short-focus mirror, 41-fifth shortwave short-focus mirror, 42-sixth shortwave short-focus mirror, 43-seventh shortwave short-focus mirror, 44-first shortwave focal mirror, 45-second shortwave focal mirror, 46-third shortwave focal mirror, 47-fourth shortwave focal mirror, 48-fifth shortwave focal mirror, 49-first infrared mirror, 50-seventh folding mirror, 51-second infrared mirror, 52-third infrared mirror, 53-fourth infrared mirror, 54-fifth infrared mirror, 55-sixth infrared mirror, 56-seventh infrared mirror, 57-first variable aperture, 58-second variable aperture, 59-attenuation plate. DETAILED DESCRIPTION

[0068] In order to make the objects, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific examples. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0069] This embodiment provides a large-aperture three-band integrated optical system, including a main reflector 1, a first spectral beam splitter 2, a first folding mirror 3, a second folding mirror 4, a second spectral beam splitter 5, a visible light optical unit, a short-wave optical unit, a third folding mirror 6 and a medium-wave optical unit.

[0070] The first spectroscopic beam splitter 2 is located in the reflective optical path of the main reflector 1. After being reflected by the main reflector 1, the infinitely distant light beam from the target is split into two paths by the first spectroscopic beam splitter 2. One path, after passing through the first spectroscopic beam splitter 2, reflects the visible light beam and the short-wave infrared light beam. In this case, the main reflector 1 and the first spectroscopic beam splitter 2 form a Cassegrain system. The other path, after passing through the first spectroscopic beam splitter 2, transmits the medium-wave infrared light beam. The main reflector 1, the first spectroscopic beam splitter 2, and the subsequent third folding mirror 6 form a Newtonian system. The use of the first spectroscopic beam splitter 2 for first-order beam splitting avoids the astigmatism introduced by a parallel plate beam splitter placed at a 45-degree angle in the converging optical path.

[0071] In this embodiment, the primary optical system consists of a primary reflector 1 and a first spectral beam splitter 2, wherein the primary reflector 1 is a total reflector with a parabolic surface; the first spectral beam splitter 2 is a meniscus germanium lens with negative optical power and convex toward the object side; the light incident surface of the first spectral beam splitter 2 is defined as its front surface, and the other surface is defined as its rear surface; the front surface is a hyperbolic surface and is coated with a spectral beam splitting film for reflecting visible light and short-wave infrared light and transmitting medium-wave infrared light; the rear surface is a spherical surface and is coated with a multi-layer anti-reflection film for transmitting medium-wave infrared light.

[0072] The first folding mirror 3, the second folding mirror 4, and the second spectral beam splitter 5 are arranged in sequence along the reflected light path of the first spectral beam splitter 2, the visible light optical unit is located on the reflected light path of the second spectral beam splitter 5, and the short-wave optical unit is located on the transmitted light path of the second spectral beam splitter 5; the third folding mirror 6 and the medium-wave optical unit are arranged in sequence along the transmitted light path of the first spectral beam splitter 2.

[0073] The second spectroscopic beam splitter 5 is a cube-shaped, absorptive quartz. Its beam-splitting surface is coated with a spectroscopic coating that reflects visible light and transmits short-wave infrared light. Placing the second spectroscopic beam splitter 5 in the converging optical path avoids the astigmatism introduced by parallel-plate beam splitters placed at a 45-degree angle in the converging optical path, while also simplifying the system architecture.

[0074] The main reflector 1 , the first spectrum beam splitter 2 , the first folding mirror 3 , the second folding mirror 4 , the second spectrum beam splitter 5 and the visible light optical unit together constitute a visible light optical system for receiving a visible light beam.

[0075] The visible light optical system consists of a primary reflector 1, a secondary reflector (first spectral beam splitter 2), a first folding mirror 3, a second folding mirror 4, and a beam splitter prism (second spectral beam splitter 5). The primary imaging system has a focal length of 5574mm, a relative aperture of 1 / 8.3, and a field of view of 0.60°. The short-focus system consists of the primary imaging system, a visible light collimator, and a visible light short-focus objective lens group; the long-focus system consists of the primary imaging system, a visible light collimator, and a visible light long-focus objective lens group. The visible light optical system uses a secondary imaging system, and variable magnification is achieved by switching between the long-focus objective lens group and the short-focus imaging objective lens group in the optical path. The visible light collimating lens group and the primary imaging system form a front telephoto system with a magnification of 18.58. The focal length of the visible light short-focus objective lens group is 113.02mm, and the focal length of the visible light long-focus objective lens group is 226.05mm, thus forming a two-speed variable magnification visible light optical system with focal lengths of 2100mm and 4200mm.

[0076] The visible light collimating lens group and the visible light short-focus objective lens group (or visible light long-focus objective lens group) are parallel lights, and a variable aperture is provided, that is, a first variable aperture 57 ( Figure 3 As shown), the system dimming is achieved by adjusting the size of the first variable aperture 57; the system adopts an internal focusing method, and focusing is achieved by axially moving the focusing lens group.

[0077] Specifically, the visible light optical unit includes a visible light collimating lens group, a visible light short-focus objective lens group and a visible light long-focus objective lens group arranged in sequence along the optical path; among them, the main reflector 1, the first spectral beam splitter 2, the first folding mirror 3, the second folding mirror 4, the second spectral beam splitter 5, the visible light collimating lens group and the visible light short-focus objective lens group together constitute a visible light short-focus optical system. Figure 1 This is the optical path diagram of the visible light short-focus optical system, with a system aperture of Φ670mm, a system focal length of 2100mm, a relative aperture of 1 / 3.14, and a field of view of 0.60°.

[0078] The main reflector 1, the first spectrum beam splitter 2, the first folding mirror 3, the second folding mirror 4, the second spectrum beam splitter 5, the visible light collimating lens group and the visible light telephoto objective lens group together constitute a visible light telephoto optical system. Figure 2 This is the optical path diagram of the visible light telephoto optical system, with a system aperture of Φ670mm, a system focal length of 4200mm, a relative aperture of 1 / 6.27, and a field of view of 0.30°.

[0079] like Figure 3As shown, the focal length of the visible light collimator group is 300 mm, the relative aperture is 1 / 8.3, and the field of view is 11.13°; the visible light collimator group includes a first collimator 7, a second collimator 8, a fourth folding mirror 9, a third collimator 10, a fourth collimator 11, a fifth collimator 12, a sixth collimator 13, a seventh collimator 14, and an eighth collimator 15, which are arranged in sequence along the reflected light path of the second spectrum splitter 5.

[0080] In this embodiment, the first collimator 7 is a meniscus heavy flint lens with negative focal power and convex toward the object side; the second collimator 8 is a positive focal power biconvex optical crystal; the fourth folding mirror 9 is a plane reflector; the third collimator 10 is a meniscus heavy flint lens with negative focal power and convex toward the object side; the fourth collimator 11 is a negative focal power biconcave light crown lens; the fifth collimator 12 is a positive focal power biconvex heavy phosphorus crown lens; the sixth collimator 13 is a meniscus heavy flint lens with negative focal power and convex toward the image side; the seventh collimator 14 is a meniscus heavy phosphorus crown lens with positive focal power and convex toward the image side; and the eighth collimator 15 is a meniscus heavy flint lens with positive focal power and convex toward the image side. The third collimator 10, the fourth collimator 11, and the fifth collimator 12 form a focusing lens group, which achieves internal focusing of the visible light optical system through axial movement.

[0081] like Figure 4 As shown, the focal length of the visible light short-focus objective lens group is 113.02 mm, the relative aperture is 1 / 3.14, and the field of view is 11.13°; the visible light short-focus objective lens group includes a first short-focus lens 16, a second short-focus lens 17, a third short-focus lens 18, a fourth short-focus lens 19, a fifth short-focus lens 20, a sixth short-focus lens 21, and a seventh short-focus lens 22 arranged in sequence along the optical path.

[0082] In this embodiment, the first short-focus lens 16 is a meniscus heavy flint lens with negative focal power and convex toward the image side; the second short-focus lens 17 is a positive-power biconvex fluorine crown lens; the third short-focus lens 18 is a negative-power biconcave light crown lens; the fourth short-focus lens 19 is a positive-power biconvex optical crystal; the fifth short-focus lens 20 is a meniscus heavy phosphorus crown lens with negative focal power and convex toward the image side; the sixth short-focus lens 21 is a positive-power meniscus fluorine crown lens with positive focal power and convex toward the object side; and the seventh short-focus lens 22 is a meniscus heavy flint lens with negative focal power and convex toward the object side.

[0083] like Figure 5 As shown, the visible light telephoto objective lens group includes a first telephoto lens 23, a second telephoto lens 24, a third telephoto lens 25, a fourth telephoto lens 26, and a fifth telephoto lens 27. The visible light telephoto objective lens group has a focal length of 226.05 mm, a relative aperture of 1 / 6.27, and a field of view of 5.58°.

[0084] In this embodiment, the first telephoto lens 23 is a biconvex optical crystal with positive optical power; the second telephoto lens 24 is a meniscus light crown lens with negative optical power and convex toward the image side; the third telephoto lens 25 is a meniscus heavy flint lens with negative optical power and convex toward the image side; the fourth telephoto lens 26 is a meniscus heavy phosphorus crown lens with negative optical power and convex toward the object side; and the fifth telephoto lens 27 is a meniscus heavy phosphorus crown lens with positive optical power and convex toward the object side.

[0085] The main reflector 1, the first spectrum beam splitter 2, the first folding mirror 3, the second folding mirror 4, the second spectrum beam splitter 5 and the short-wave optical unit together constitute a short-wave infrared optical system for receiving a short-wave infrared light beam.

[0086] The shortwave infrared optical system consists of a primary reflector 1, a secondary reflector (first spectrum beam splitter 2), a first folding mirror 3, a second folding mirror 4, and a beam splitter prism (second spectrum beam splitter 5). The shortwave short-focus system consists of a shortwave primary imaging system, a shortwave collimator group, and a shortwave short-focus objective group; the shortwave focus system consists of a shortwave primary imaging system, a shortwave collimator group, and a shortwave focus objective group. The shortwave infrared optical system uses a secondary imaging system, achieving variable magnification by switching between the shortwave focus objective group and the shortwave short-focus imaging objective group in the optical path. The shortwave collimator group and the primary imaging system form a front telescope system with a magnification of 18.58. The focal length of the shortwave short-focus objective group is 72.12mm, and the focal length of the shortwave focus objective group is 144.24mm. This creates a two-speed variable magnification shortwave infrared optical system with focal lengths of 1340mm and 2680mm.

[0087] There is parallel light between the short-wave collimator lens group and the short-wave short-focus objective lens group (or the long-focus objective lens group), and a short-wave variable aperture is provided. An attenuation plate is provided in front of the detector, that is, a second variable aperture 58 is provided between the seventh short-wave collimator lens 36 and the first short-wave short-focus lens 37 or the first short-wavelength focal lens 44 ( Figure 8 As shown), at the light-emitting ends of the seventh short-wavelength short-focus lens 43 and the fifth short-wavelength short-focus lens 48, attenuation plates 59 ( Figure 9 As shown), the system dimming is achieved by adjusting the size of the short-wave second variable aperture 58 and changing the attenuation plate 59; the short-wave system adopts an external focusing method and achieves focusing by axially moving the detector.

[0088] Specifically, the short-wave optical unit includes a short-wave collimating lens group, a short-wave short-focus objective lens group and a short-wavelength short-focus objective lens group arranged in sequence along the optical path; among them, the main reflector 1, the first spectral beam splitter 2, the first folding mirror 3, the second folding mirror 4, the second spectral beam splitter, the short-wave collimating lens group and the short-wave short-focus objective lens group together constitute a short-wave short-focus infrared optical system. Figure 6 The figure shows the optical path diagram of the short-wave infrared short-focus optical system, with a system aperture of Φ670mm, a system focal length of 1340mm, a relative aperture of 1 / 2, and a field of view of 0.52°.

[0089] The main reflector 1, the first spectrum beam splitter 2, the first folding mirror 3, the second folding mirror 4, the second spectrum beam splitter 5, the short-wave collimating lens group and the short-wavelength focus objective lens group together constitute a short-wavelength focus infrared optical system. Figure 7 The figure shows the optical path diagram of the short-wave infrared telephoto optical system, with a system aperture of Φ670mm, a system focal length of 2680mm, a relative aperture of 1 / 4, and a field of view of 0.26°.

[0090] like Figure 8 As shown, the shortwave collimator assembly includes a first shortwave collimator 28, a fifth folding mirror 29, a second shortwave collimator 30, a third shortwave collimator 31, a fourth shortwave collimator 32, a fifth shortwave collimator 33, a sixth shortwave collimator 34, a sixth folding mirror 35, and a seventh shortwave collimator 36, which are sequentially arranged along the transmission light path of the first spectrum splitter 2. The shortwave collimator assembly has a focal length of 300 mm, a relative aperture of 1 / 8.3, and a field of view of 9.74°. Among them, the first short-wave collimator 28 is a positive optical focal length biconvex heavy flint lens; the fifth folding mirror 29 is a plane reflector; the second short-wave collimator 30 is a negative optical focal length meniscus heavy flint lens convex toward the object side; the third short-wave collimator 31 is a negative optical focal length biconcave light crown lens; the fourth short-wave collimator 32 is a positive optical focal length biconvex heavy phosphorus crown lens; the fifth short-wave collimator 33 is a negative optical focal length meniscus heavy flint lens convex toward the image side; the sixth short-wave collimator 34 is a positive optical focal length meniscus heavy phosphorus crown lens convex toward the image side; the sixth folding mirror 35 is a plane reflector; the seventh short-wave collimator 36 is a positive optical focal length biconvex heavy flint lens.

[0091] like Figure 9 As shown, the short-wavelength, short-focus objective lens assembly includes a first short-wavelength, short-focus lens 37, a second short-wavelength, short-focus lens 38, a third short-wavelength, short-focus lens 39, a fourth short-wavelength, short-focus lens 40, a fifth short-wavelength, short-focus lens 41, a sixth short-wavelength, short-focus lens 42, and a seventh short-wavelength, short-focus lens 43, arranged sequentially along the optical path. The short-wavelength, short-focus objective lens assembly has a focal length of 72.12 mm, a relative aperture of 1 / 2, and a field of view of 9.74°.

[0092] Among them, the first short-wavelength short-focus lens 37 is a meniscus heavy flint lens with negative focal power convex toward the image side; the second short-wavelength short-focus lens 38 is a meniscus fluorine crown lens with positive focal power convex toward the object side; the third short-wavelength short-focus lens 39 is a meniscus light crown lens with negative focal power convex toward the object side; the fourth short-wavelength short-focus lens 40 is a positive focal power biconvex optical crystal; the fifth short-wavelength short-focus lens 41 is a meniscus heavy flint lens with negative focal power convex toward the image side; the sixth short-wavelength short-focus lens 42 is a positive focal power biconvex heavy phosphorus crown lens; the seventh short-wavelength short-focus lens 43 is a meniscus heavy flint lens with negative focal power convex toward the object side.

[0093] like Figure 10As shown, the short-wavelength focusing objective lens assembly includes a first short-wavelength focusing lens 44, a second short-wavelength focusing lens 45, a third short-wavelength focusing lens 46, a fourth short-wavelength focusing lens 47, and a fifth short-wavelength focusing lens 48, arranged sequentially along the optical path. The short-wavelength focusing objective lens assembly has a focal length of 144.24 mm, a relative aperture of 1 / 4, and a field of view of 4.88°.

[0094] Among them, the first short-wavelength focal lens 44 is a positive-power biconvex heavy phosphor crown lens; the second short-wavelength focal lens 45 is a negative-power biconcave light crown lens; the third short-wavelength focal lens 46 is a negative-power meniscus heavy flint lens convex toward the object; the fourth short-wavelength focal lens 47 is a positive-power biconvex fluorine crown lens; and the fifth short-wavelength focal lens 48 is a negative-power meniscus heavy phosphor crown lens convex toward the object.

[0095] The main reflector 1, the first spectrum splitter 2, the third folding mirror 6 and the medium-wave optical unit together constitute a medium-wave infrared optical system for receiving a medium-wave infrared light beam. Figure 11 This is the optical path diagram of the medium-wave infrared focal length optical system. The system aperture is Φ670mm, the system focal length is 2680mm, the relative aperture is 1 / 4, and the field of view is 0.43°.

[0096] The MWIR optical system consists of a primary reflector 1, a secondary reflector (first spectroscope 2), a third folding mirror 6, and a first infrared mirror 49. The MWIR primary imaging system has a focal length of 2600 mm, a relative aperture of 1 / 3.88, and a field of view of 0.44°. The MWIR secondary imaging system, along with the seventh folding mirror 50, a second infrared mirror 51, a third infrared mirror 52, and a fourth infrared mirror 53, forms the MWIR primary imaging system. The second infrared mirror 51 is a MWIR collimator with a focal length of 150 mm. Together, the MWIR collimator and the MWIR primary imaging system form a MWIR pre-telescope system with a magnification of 17.33. The projection lens assembly has a focal length of 24 mm. The MWIR secondary imaging system and the projection lens assembly form a tertiary imaging optical system. The central portion of the MWIR secondary imaging system is designed for parallel light, facilitating system beam splitting, cold screen matching, and structural spatial layout. The use of high-order aspheric surfaces effectively simplifies the system structure and improves imaging quality and transmittance. The medium wave system adopts external focusing method, which realizes focusing by moving the detector axially.

[0097] Specifically, the medium-wave optical unit includes a medium-wave infrared mirror group and a projection mirror group arranged in sequence along the optical path, wherein the medium-wave infrared mirror group includes a first infrared mirror 49, a seventh folding mirror 50, a second infrared mirror 51, a third infrared mirror 52, and a fourth infrared mirror 53 arranged in sequence along the reflected light path of the third folding mirror 6.

[0098] like Figure 11As shown, in this embodiment, the first infrared mirror 49 is a meniscus ZnS lens with positive optical focal length convex toward the image side; the seventh folding mirror 50 is a plane reflecting mirror; the second infrared mirror 51 is a meniscus germanium lens with positive optical focal length convex toward the object side; the third infrared mirror 52 is a meniscus germanium lens with negative optical focal length convex toward the object side; and the fourth infrared mirror 53 is a meniscus germanium lens with positive optical focal length convex toward the object side.

[0099] The projection lens group includes a fifth infrared mirror 54, a sixth infrared mirror 55, and a seventh infrared mirror 56 arranged in sequence along the optical path; among them, the fifth infrared mirror 54 is a meniscus ZnS lens with negative optical focal length and convex toward the image side; the sixth infrared mirror 55 is a meniscus germanium lens with negative optical focal length and convex toward the object side; and the seventh infrared mirror 56 is a biconvex silicon lens with positive optical focal length.

[0100] The parameters of the above lenses are shown in Table 1:

[0101] Table 1 Optical parameters of each lens (unit: mm)

[0102]

[0103]

[0104]

[0105]

[0106] The aspheric surfaces described in Table 1 are all even-order spheres, and the aspheric surface equation is:

[0107]

[0108] Where, z is the aspheric surface sagittal height (z coordinate), unit is mm;

[0109] r——radial distance, unit: mm, c——curvature (corresponding to the radius);

[0110] k——conic curve constant;

[0111] A——r 4 Term coefficient;

[0112] B——r 6 Term coefficient;

[0113] C——r 8 Term coefficient.

[0114] The unit of curvature radius is mm.

[0115] The present invention provides a large-aperture, three-band integrated optical system that utilizes a spectroscopic spectral splitting method to create a three-band integrated optical system with a single main optical system for visible light, short-wave infrared, and medium-wave infrared. The optical system has an entrance pupil diameter (i.e., aperture) of 670 mm, a two-step zoom range of 2100 mm / 4200 mm for the visible light system, a two-step zoom range of 1340 mm / 2680 mm for the short-wave infrared system, and a medium-wave infrared system with a focal length of 2680 mm. This system offers advantages such as compact and reasonable spectrometry, high imaging quality, and the ability to be expanded into a four-band integrated optical system.

[0116] The visible light optical system of this embodiment is suitable for visible light detectors with a resolution of 1920×1080 and a pixel pitch of 10μm×10μm. The short-wave infrared optical system is suitable for short-wave infrared detectors with a resolution of 640×512 and a pixel pitch of 15μm×15μm. The medium-wave infrared optical system is suitable for cooled medium-wave infrared thermal imagers with a resolution of 640×512, a pixel pitch of 25μm×25μm, and a cold screen F-number of F4.

[0117] Figures 12 to 16 They are the MTF curves of the visible light short-focus 2100mm optical system, the MTF curves of the visible light long-focus 4200mm optical system, the MTF curves of the short-wave infrared short-focus 1340mm optical system, the MTF curves of the short-wave infrared long-focus 2680mm optical system, and the MTF curves of the medium-wave infrared focal length 2680mm optical system.

[0118] Figures 17 to 21 They are the spherical aberration, field curvature and distortion curves of the visible light short-focus 2100mm optical system, the spherical aberration, field curvature and distortion curves of the visible light long-focus 4200mm optical system, the spherical aberration, field curvature and distortion curves of the short-wave infrared short-focus 1340mm optical system, the spherical aberration, field curvature and distortion curves of the short-wave infrared long-focus 2680mm optical system, and the spherical aberration, field curvature and distortion curves of the medium-wave infrared focal length 2680mm optical system.

[0119] As can be seen from the figure, the MTFs of the visible light telephoto system, visible light short-focus system, short-wave infrared short-focus system, short-wave infrared telephoto system, and medium-wave infrared system are all close to the diffraction limit. The optical systems all have high imaging quality, and the distortion of each optical system is small, which fully meets the needs of high-precision measurement of the target.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A large-aperture three-band integrated optical system, characterized in that: It comprises a main reflector (1), a first spectrum splitter (2), a first folding mirror (3), a second folding mirror (4), a second spectrum splitter (5), a visible light optical unit, a short-wave optical unit, a third folding mirror (6) and a medium-wave optical unit; The first spectrum beam splitter (2) is located on the reflection light path of the main reflection mirror (1); the light beam from the target object is reflected by the main reflection mirror (1) and then split into two paths by the first spectrum beam splitter (2); one path reflects a visible light beam and a short-wave infrared light beam after passing through the first spectrum beam splitter (2), and the other path transmits a medium-wave infrared light beam after passing through the first spectrum beam splitter (2); The first folding mirror (3), the second folding mirror (4), and the second spectrum beam splitter (5) are arranged in sequence along the reflection light path of the first spectrum beam splitter (2); the visible light optical unit is located on the reflection light path of the second spectrum beam splitter (5); and the short-wave optical unit is located on the transmission light path of the second spectrum beam splitter (5); the third folding mirror (6) and the medium-wave optical unit are arranged in sequence along the transmission light path of the first spectrum beam splitter (2); The main reflector (1), the first spectrum splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum splitter (5) and the visible light optical unit together constitute a visible light optical system for receiving a visible light beam; The main reflector (1), the first spectrum splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum splitter (5) and the short-wave optical unit together form a short-wave infrared optical system for receiving a short-wave infrared light beam; The main reflector (1), the first spectrum splitter (2), the third folding mirror (6) and the medium-wave optical unit together form a medium-wave infrared optical system for receiving a medium-wave infrared light beam.

2. The large-aperture three-band integrated optical system according to claim 1, characterized in that: The visible light optical unit comprises a visible light collimator group, a visible light short-focus objective group and a visible light long-focus objective group which are arranged in sequence along the light path; wherein the main reflector (1), the first spectrum beam splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum beam splitter (5), the visible light collimator group and the visible light short-focus objective group together constitute a visible light short-focus optical system; the main reflector (1), the first spectrum beam splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum beam splitter (5), the visible light collimator group and the visible light long-focus objective group together constitute a visible light long-focus optical system; The short-wave optical unit comprises a short-wave collimator group, a short-wave short-focus objective group and a short-wavelength focus objective group which are arranged in sequence along the optical path; wherein the main reflector (1), the first spectrum splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum splitter, the short-wave collimator group and the short-wavelength focus objective group together constitute a short-wavelength short-focus infrared optical system; the main reflector (1), the first spectrum splitter (2), the first folding mirror (3), the second folding mirror (4), the second spectrum splitter (5), the short-wave collimator group and the short-wavelength focus objective group together constitute a short-wavelength focus infrared optical system; The medium wave optical unit comprises a medium wave infrared lens group and a projection lens group which are sequentially arranged along the optical path.

3. The large-aperture three-band integrated optical system according to claim 2, characterized in that: The visible light collimating mirror group comprises a first collimating mirror (7), a second collimating mirror (8), a fourth folding mirror (9), a third collimating mirror (10), a fourth collimating mirror (11), a fifth collimating mirror (12), a sixth collimating mirror (13), a seventh collimating mirror (14), and an eighth collimating mirror (15) which are sequentially arranged along the reflection light path of the second spectrum splitter (5); The first collimator (7) is a meniscus heavy flint lens with negative focal power and convex toward the object side; the second collimator (8) is a positive focal power biconvex optical crystal; the fourth folding mirror (9) is a plane reflector; the third collimator (10) is a meniscus heavy flint lens with negative focal power and convex toward the object side; the fourth collimator (11) is a negative focal power biconcave light crown lens; the fifth collimator (12) is a positive focal power biconvex heavy phosphorus crown lens; the sixth collimator (13) is a meniscus heavy flint lens with negative focal power and convex toward the image side; the seventh collimator (14) is a meniscus heavy phosphorus crown lens with positive focal power and convex toward the image side; and the eighth collimator (15) is a meniscus heavy flint lens with positive focal power and convex toward the image side. The visible light short-focus objective lens group comprises a first short-focus lens (16), a second short-focus lens (17), a third short-focus lens (18), a fourth short-focus lens (19), a fifth short-focus lens (20), a sixth short-focus lens (21), and a seventh short-focus lens (22) which are sequentially arranged along the light path; The first short-focus lens (16) is a meniscus heavy flint lens with negative focal power and convex toward the image side; the second short-focus lens (17) is a positive focal power biconvex fluorine crown lens; the third short-focus lens (18) is a negative focal power biconcave light crown lens; the fourth short-focus lens (19) is a positive focal power biconvex optical crystal; the fifth short-focus lens (20) is a meniscus heavy phosphorus crown lens with negative focal power and convex toward the image side; the sixth short-focus lens (21) is a meniscus fluorine crown lens with positive focal power and convex toward the object side; and the seventh short-focus lens (22) is a meniscus heavy flint lens with negative focal power and convex toward the object side. The visible light telephoto objective lens group comprises a first telephoto lens (23), a second telephoto lens (24), a third telephoto lens (25), a fourth telephoto lens (26), and a fifth telephoto lens (27); The first telephoto lens (23) is a positive-power biconvex optical crystal; the second telephoto lens (24) is a meniscus light crown lens with negative power and convex toward the image side; the third telephoto lens (25) is a meniscus heavy flint lens with negative power and convex toward the image side; the fourth telephoto lens (26) is a meniscus heavy phosphorus crown lens with negative power and convex toward the object side; and the fifth telephoto lens (27) is a meniscus heavy phosphorus crown lens with positive power and convex toward the object side.

4. The large-aperture three-band integrated optical system according to claim 3, characterized in that: The visible light optical unit adopts an internal focusing mode, which is achieved by axially moving a focusing lens group consisting of a third collimator lens (10), a fourth collimator lens (11), and a fifth collimator lens (12).

5. The large-aperture three-band integrated optical system according to claim 2, characterized in that: The short-wave collimator group comprises a first short-wave collimator (28), a fifth folding mirror (29), a second short-wave collimator (30), a third short-wave collimator (31), a fourth short-wave collimator (32), a fifth short-wave collimator (33), a sixth short-wave collimator (34), a sixth folding mirror (35) and a seventh short-wave collimator (36) which are sequentially arranged along the transmission light path of the first spectrum splitter (2); The first short-wave collimator (28) is a positive focal power double convex heavy flint lens; the fifth folding axis mirror (29) is a plane reflector; the second short-wave collimator (30) is a negative focal power meniscus heavy flint lens convex toward the object side; the third short-wave collimator (31) is a negative focal power double concave light crown lens; the fourth short-wave collimator (32) is a positive focal power double convex heavy phosphorus crown lens; the fifth short-wave collimator (33) is a negative focal power meniscus heavy flint lens convex toward the image side; the sixth short-wave collimator (34) is a positive focal power meniscus heavy phosphorus crown lens convex toward the image side; the sixth folding axis mirror (35) is a plane reflector; the seventh short-wave collimator (36) is a positive focal power double convex heavy flint lens; The short-wavelength short-focus objective lens group comprises a first short-wavelength short-focus lens (37), a second short-wavelength short-focus lens (38), a third short-wavelength short-focus lens (39), a fourth short-wavelength short-focus lens (40), a fifth short-wavelength short-focus lens (41), a sixth short-wavelength short-focus lens (42), and a seventh short-wavelength short-focus lens (43) which are sequentially arranged along the optical path; The first short-wavelength short-focus lens (37) is a meniscus heavy flint lens with negative focal power and convex toward the image side; the second short-wavelength short-focus lens (38) is a meniscus fluorine crown lens with positive focal power and convex toward the object side; the third short-wavelength short-focus lens (39) is a meniscus light crown lens with negative focal power and convex toward the object side; the fourth short-wavelength short-focus lens (40) is a positive focal power double convex optical crystal; the fifth short-wavelength short-focus lens (41) is a meniscus heavy flint lens with negative focal power and convex toward the image side; the sixth short-wavelength short-focus lens (42) is a positive focal power double convex heavy phosphorus crown lens; and the seventh short-wavelength short-focus lens (43) is a meniscus heavy flint lens with negative focal power and convex toward the object side. The short-wavelength focal lens group comprises a first short-wavelength focal lens (44), a second short-wavelength focal lens (45), a third short-wavelength focal lens (46), a fourth short-wavelength focal lens (47) and a fifth short-wavelength focal lens (48) which are sequentially arranged along the optical path; The first short-wavelength focal lens (44) is a positive-power double-convex heavy phosphor crown lens; the second short-wavelength focal lens (45) is a negative-power double-concave light crown lens; the third short-wavelength focal lens (46) is a negative-power meniscus heavy flint lens convex toward the object; the fourth short-wavelength focal lens (47) is a positive-power double-convex fluorine crown lens; and the fifth short-wavelength focal lens (48) is a negative-power meniscus heavy phosphor crown lens convex toward the object.

6. The large-aperture three-band integrated optical system according to claim 2, characterized in that: The medium-wave infrared mirror group comprises a first infrared mirror (49), a seventh infrared mirror (50), a second infrared mirror (51), a third infrared mirror (52), and a fourth infrared mirror (53) which are sequentially arranged along the reflection light path of the third folding mirror (6); The first infrared mirror (49) is a positive ZnS lens with a positive focal length and a convex shape toward the image side; the seventh folding mirror (50) is a plane reflector; the second infrared mirror (51) is a positive germanium lens with a convex shape toward the object side; the third infrared mirror (52) is a negative germanium lens with a convex shape toward the object side; and the fourth infrared mirror (53) is a positive germanium lens with a convex shape toward the object side. The projection lens group comprises a fifth infrared mirror (54), a sixth infrared mirror (55), and a seventh infrared mirror (56) which are arranged in sequence along the optical path; wherein the fifth infrared mirror (54) is a meniscus ZnS lens with negative optical power and convex toward the image side; the sixth infrared mirror (55) is a meniscus germanium lens with negative optical power and convex toward the object side; and the seventh infrared mirror (56) is a double convex silicon lens with positive optical power.

7. The large-aperture three-band integrated optical system according to any one of claims 1 to 6, characterized in that: The main reflector (1) is a total reflector, and its surface shape is a parabola; The first spectrum spectroscope (2) is a meniscus germanium lens with negative focal length and convex toward the object side; the light incident surface of the first spectrum spectroscope (2) is defined as its front surface, and the other surface is defined as its rear surface; the front surface is a hyperbolic surface and is coated with a spectrum spectroscope film for reflecting visible light and short-wave infrared light and transmitting medium-wave infrared light; the rear surface is a spherical surface and is coated with a multi-layer anti-reflection film for transmitting medium-wave infrared light; The second spectrum beam splitter (5) is a cube without optical focal length, and a beam splitting film is coated on the beam splitting surface, and is used for reflecting visible light and transmitting short-wave infrared light.

8. The large-aperture three-band integrated optical system according to claim 7, characterized in that: The second spectrum splitter (5) is made of quartz.

9. The large-aperture three-band integrated optical system according to claim 3, characterized in that: A first variable diaphragm (57) is arranged between the eighth collimating lens (15) and the first short-focus lens (16) or the first long-focus lens (23).

10. The large-aperture three-band integrated optical system according to claim 5, characterized in that: A second variable diaphragm (58) is provided between the seventh short-wave collimating lens (36) and the first short-wave short-focus lens (37) or the first short-wavelength focal lens (44); Attenuation plates (59) are respectively provided at the light output ends of the seventh short-wavelength short-focus lens (43) and the fifth short-wavelength short-focus lens (48).

Images