Large aperture three-waveband integrated optical system

Abstract

The application discloses a large-aperture three-waveband integrated optical system, and solves the technical problem of a large volume and weight of an existing multi-waveband imaging system. The optical system comprises a main reflector, a first spectral light splitter, a first fold mirror, a second fold mirror, a second spectral light splitter, a visible light optical unit, a short-wave optical unit, a third fold mirror and a medium-wave optical unit; wherein the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter and the visible light optical unit form a visible light optical system and receive a visible light beam; the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter and the short-wave optical unit form a short-wave infrared optical system and receive a short-wave infrared light beam; and the main reflector, the first spectral light splitter, the third fold mirror and the medium-wave optical unit form a medium-wave infrared optical system and receive a medium-wave infrared light beam. The optical system adopts a modular design and has high integration.

Description

TECHNICAL FIELD

[0001] The present application relates to a three-band integrated optical system, in particular to a large-aperture visible light / short-wave infrared / mid-wave infrared three-band integrated optical system. BACKGROUND

[0002] With the continuous progress of target camouflage and stealth technology, the information that can be detected by traditional single-band equipment cannot meet the demand of target detection. In order to meet the requirement of all-day observation, multiple-band imaging systems need to be used to realize information acquisition of targets.

[0003] At present, the visible light system mainly relies on the sunlight reflected by the target for imaging, and its performance is greatly reduced or even cannot be used under night and low-light conditions. In addition, the visible light system is easily disturbed by the environment, and it is difficult to observe when there is fog or obstruction. The infrared band mainly relies on the self-radiation of the target for detection and imaging, and the infrared system can be observed whether it is day or night or the environment is relatively bad. Compared with the visible light system, the infrared system can more safely and stealthily identify targets or targets disguised as targets.

[0004] With the continuous increase of the aperture of the system, the traditional three independent imaging systems gradually expose the shortcomings of large volume and heavy weight, which do not meet the development demand of miniaturization and light weight of the system. Therefore, a visible light, short-wave infrared, and mid-wave infrared three-in-one system needs to be designed to meet the optical system of high visible light resolution and infrared high-sensitivity detection mutual compensation. SUMMARY

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

[0006] To achieve the above purpose, the technical solution provided by the present application is:

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

[0008] It comprises a main reflector, a first spectral light splitter, a first fold mirror, a second fold mirror, a second spectral light splitter, a visible light optical unit, a short-wave optical unit, a third fold mirror, and a mid-wave optical unit.

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

[0010] The first fold mirror, the second fold mirror, and the second spectral light splitter are sequentially arranged along a reflection light path of the first spectral light splitter, the visible light optical unit is located on a reflection light path of the second spectral light splitter, and the short-wave optical unit is located on a transmission light path of the second spectral light splitter; the third fold mirror and the middle-wave optical unit are sequentially arranged along a transmission light path of the first spectral light splitter.

[0011] The main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, and the visible light optical unit jointly form a visible light optical system for receiving a visible light beam.

[0012] The main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, and the short-wave optical unit jointly form a short-wave infrared optical system for receiving a short-wave infrared light beam.

[0013] The main reflector, the first spectral light splitter, the third fold mirror, and the middle-wave optical unit jointly form a middle-wave infrared optical system for receiving a middle-wave infrared light beam.

[0014] Further, the visible light optical unit comprises a visible light collimating mirror group, a visible light short-focus objective lens group, and a visible light long-focus objective lens group sequentially arranged along a light path; wherein the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, the visible light collimating mirror group, and the visible light short-focus objective lens group jointly form a visible light short-focus optical system; and the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, the visible light collimating mirror group, and the visible light long-focus objective lens group jointly form a visible light long-focus optical system.

[0015] The short-wave optical unit comprises a short-wave collimating mirror group, a short-wave short-focus objective lens group, and a short-wave long-focus objective lens group sequentially arranged along a light path; wherein the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, the short-wave collimating mirror group, and the short-wave short-focus objective lens group jointly form a short-wave short-focus infrared optical system; and the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter, the short-wave collimating mirror group, and the short-wave long-focus objective lens group jointly form a short-wave long-focus infrared optical system.

[0016] The middle-wave optical unit comprises a middle-wave infrared mirror group and a projection mirror group sequentially arranged along a light path.

[0017] Further, the visible light collimating mirror group comprises a first collimating mirror, a second collimating mirror, a fourth fold 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 sequentially arranged along a reflection light path of the second spectral light splitter.

[0018] The first collimating mirror is a negative light focusing convex meniscus heavy flint lens; the second collimating mirror is a positive light focusing double-convex optical crystal; the fourth fold mirror is a plane mirror; the third collimating mirror is a negative light focusing convex meniscus heavy flint lens; the fourth collimating mirror is a negative light focusing double-concave light crown lens; the fifth collimating mirror is a positive light focusing double-convex heavy fluorite lens; the sixth collimating mirror is a negative light focusing convex meniscus heavy phosphor crown lens; the seventh collimating mirror is a positive light focusing convex meniscus heavy flint lens; and the eighth collimating mirror is a positive light focusing convex meniscus heavy flint lens.

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

[0020] The first short-focus mirror is a negative light focusing convex meniscus heavy flint lens; the second short-focus mirror is a positive light focusing double-convex fluorite lens; the third short-focus mirror is a negative light focusing double-concave light crown lens; the fourth short-focus mirror is a positive light focusing double-convex optical crystal; the fifth short-focus mirror is a negative light focusing convex meniscus heavy phosphor crown lens; the sixth short-focus mirror is a positive light focusing convex meniscus fluorite lens; and the seventh short-focus mirror is a negative light focusing convex meniscus heavy flint lens.

[0021] The visible light long-focus objective lens group comprises a first long-focus mirror, a second long-focus mirror, a third long-focus mirror, a fourth long-focus mirror and a fifth long-focus mirror.

[0022] The first long-focus mirror is a positive light focusing double-convex optical crystal; the second long-focus mirror is a negative light focusing convex meniscus light crown lens; the third long-focus mirror is a negative light focusing convex meniscus heavy flint lens; the fourth long-focus mirror is a negative light focusing convex meniscus heavy phosphor crown lens; and the fifth long-focus mirror is a positive light focusing convex meniscus heavy phosphor crown lens.

[0023] Further, the visible light optical unit is an internal focusing type, and focusing is achieved by axially moving a focusing lens group composed of the third collimating mirror, the fourth collimating mirror and the fifth collimating mirror.

[0024] Further, the short-wave collimating mirror group comprises a first short-wave collimating mirror, a fifth fold mirror, a second short-wave collimating mirror, a third short-wave collimating mirror, a fourth short-wave collimating mirror, a fifth short-wave collimating mirror, a sixth short-wave collimating mirror, a sixth fold mirror and a seventh short-wave collimating mirror arranged in sequence along a transmission light path of the first spectrum splitting mirror.

[0025] The first short-wave collimating mirror is a positive focal length lenticular heavy flint lens; the fifth fold mirror is a plane mirror; the second short-wave collimating mirror is a negative focal length meniscus heavy flint lens convex to the object side; the third short-wave collimating mirror is a negative focal length biconcave light crown lens; the fourth short-wave collimating mirror is a positive focal length lenticular heavy phosphor crown lens; the fifth short-wave collimating mirror is a negative focal length meniscus heavy flint lens convex to the image side; the sixth short-wave collimating mirror is a positive focal length meniscus heavy phosphor crown lens convex to the image side; the sixth fold mirror is a plane mirror; and the seventh short-wave collimating mirror is a positive focal length lenticular heavy flint lens.

[0026] The short-wave short-focus objective lens group comprises, in sequence along an optical path, a first short-wave short-focus mirror, a second short-wave short-focus mirror, a third short-wave short-focus mirror, a fourth short-wave short-focus mirror, a fifth short-wave short-focus mirror, a sixth short-wave short-focus mirror and a seventh short-wave short-focus mirror.

[0027] The first short-wave short-focus mirror is a negative focal length meniscus heavy flint lens convex to the image side; the second short-wave short-focus mirror is a positive focal length meniscus fluor crown lens convex to the object side; the third short-wave short-focus mirror is a negative focal length meniscus light crown lens convex to the object side; the fourth short-wave short-focus mirror is a positive focal length lenticular optical crystal; the fifth short-wave short-focus mirror is a negative focal length meniscus heavy flint lens convex to the image side; the sixth short-wave short-focus mirror is a positive focal length lenticular heavy phosphor crown lens; and the seventh short-wave short-focus mirror is a negative focal length meniscus heavy flint lens convex to the object side.

[0028] The short-wave long-focus objective lens group comprises, in sequence along an optical path, a first short-wave long-focus mirror, a second short-wave long-focus mirror, a third short-wave long-focus mirror, a fourth short-wave long-focus mirror and a fifth short-wave long-focus mirror.

[0029] The first short-wave long-focus mirror is a positive focal length lenticular heavy phosphor crown lens; the second short-wave long-focus mirror is a negative focal length biconcave light crown lens; the third short-wave long-focus mirror is a negative focal length meniscus heavy flint lens convex to the object side; the fourth short-wave long-focus mirror is a positive focal length lenticular fluor crown lens; and the fifth short-wave long-focus mirror is a negative focal length meniscus heavy phosphor crown lens convex to the object side.

[0030] Further, the mid-wave infrared mirror group comprises, in sequence along a reflection optical path of the third fold mirror, a first infrared mirror, a seventh fold mirror, a second infrared mirror, a third infrared mirror and a fourth infrared mirror.

[0031] The first infrared mirror is a positive focal length meniscus ZnS lens convex to the image side; the seventh fold mirror is a plane mirror; the second infrared mirror is a positive focal length meniscus Ge lens convex to the object side; the third infrared mirror is a negative focal length meniscus Ge lens convex to the object side; and the fourth infrared mirror is a positive focal length meniscus Ge lens convex to the object side.

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

[0033] Further, the main reflector is a full reflector, and the surface type is a parabolic surface.

[0034] The first spectral light splitter is a negative focal length convex meniscus germanium lens facing the object side; the light incident surface of the first spectral light splitter is defined as the front surface thereof, and the other surface is the back surface thereof; the front surface is a double curved surface, and is coated with a spectral light splitting film for reflecting visible light and short-wave infrared light and transmitting mid-wave infrared light; and the back surface is a spherical surface, and is coated with a multilayer anti-reflection film for transmitting mid-wave infrared light.

[0035] The second spectral light splitter is a positive cube without focal length, and the light splitting surface is coated with a light splitting film for reflecting visible light and transmitting short-wave infrared light.

[0036] Further, the second spectral light splitter is made of quartz.

[0037] Further, a first variable diaphragm is arranged between the eighth collimating mirror and the first short-focus mirror or the first long-focus mirror.

[0038] Further, a second variable diaphragm is arranged between the seventh short-wave collimating mirror and the first short-wave short-focus mirror or the first short-wave long-focus mirror.

[0039] The light emitting end of the seventh short-wave short-focus mirror and the fifth short-wave long-focus mirror is respectively provided with an attenuation sheet.

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

[0041] 1. The main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter and the visible light optical unit of the present application jointly constitute a visible light optical system for receiving a visible light beam; the main reflector, the first spectral light splitter, the first fold mirror, the second fold mirror, the second spectral light splitter and the short-wave optical unit jointly constitute a short-wave infrared optical system for receiving a short-wave infrared light beam; and the main reflector, the first spectral light splitter, the third fold mirror and the mid-wave optical unit jointly constitute a mid-wave infrared optical system for receiving a mid-wave infrared light beam, thereby forming a three-band integrated optical system structure type in which a main optical system is shared by visible light, short-wave infrared light and mid-wave infrared light. The present application adopts a modular design, and each part can be independently detected, so that the overall integration degree of the optical system is high, and the volume and weight of the system are reduced.

[0042] 2、The first spectral spectroscope is used for first-order spectrometry, and the second spectral spectroscope is used for second-order spectrometry, so that the astigmatism introduced by the parallel flat-plate spectroscope placed at 45 degrees in the converging light path is avoided, and the imaging quality is improved.

[0043] 3、The visible light optical system and the short-wave infrared optical system can realize two-grade zooming, the whole optical system is reasonable and compact in spectrometry, the imaging quality is high, and the optical system has the advantages of expansion into a four-waveband integrated optical system.

[0044] 4、The modular structure design is adopted, the assembly process is controlled, the difficulty of system assembly and adjustment is effectively reduced, and the high-quality imaging of the optical system is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a visible light short-focus optical system light path diagram in the embodiment of the application.

[0046] Figure 2 It is a visible light long-focus optical system light path diagram in the embodiment of the application.

[0047] Figure 3 It is a visible light collimating mirror group light path diagram in the embodiment of the application.

[0048] Figure 4 It is a visible light short-focus objective lens group light path diagram in the embodiment of the application.

[0049] Figure 5 It is a visible light long-focus objective lens group light path diagram in the embodiment of the application.

[0050] Figure 6 It is a short-wave infrared short-focus optical system light path diagram in the embodiment of the application.

[0051] Figure 7 It is a short-wave infrared long-focus optical system light path diagram in the embodiment of the application.

[0052] Figure 8 It is a short-wave collimating mirror group light path diagram in the embodiment of the application.

[0053] Figure 9 It is a short-wave short-focus objective lens group light path diagram in the embodiment of the application.

[0054] Figure 10 It is a short-wave long-focus objective lens group light path diagram in the embodiment of the application.

[0055] Figure 11 It is a medium-wave infrared focal length optical system light path diagram in the embodiment of the application.

[0056] Figure 12Figure 8 is a MTF curve diagram of a visible light short focal length 2100mm optical system in an embodiment of the present application, with a spatial frequency of 50lp / mm.

[0057] Figure 13 Figure 9 is a MTF curve diagram of a visible light long focal length 4200mm optical system in an embodiment of the present application, with a spatial frequency of 50lp / mm.

[0058] Figure 14 Figure 10 is a MTF curve diagram of a short wave infrared short focal length 1340mm optical system in an embodiment of the present application, with a spatial frequency of 33lp / mm.

[0059] Figure 15 Figure 11 is a MTF curve diagram of a short wave infrared long focal length 2680mm optical system in an embodiment of the present application, with a spatial frequency of 33lp / mm.

[0060] Figure 16 Figure 12 is a MTF curve diagram of a medium wave infrared focal length 2680mm optical system in an embodiment of the present application, with a spatial frequency of 20lp / mm.

[0061] Figure 17 Figure 13 is a spherical aberration, field curvature and distortion curve diagram of a visible light short focal length 2100mm optical system in an embodiment of the present application.

[0062] Figure 18 Figure 14 is a spherical aberration, field curvature and distortion curve diagram of a visible light long focal length 4200mm optical system in an embodiment of the present application.

[0063] Figure 19 Figure 15 is a spherical aberration, field curvature and distortion curve diagram of a short wave infrared short focal length 1340mm optical system in an embodiment of the present application.

[0064] Figure 20 Figure 16 is a spherical aberration, field curvature and distortion curve diagram of a short wave infrared long focal length 2680mm optical system in an embodiment of the present application.

[0065] Figure 21 Figure 17 is a spherical aberration, field curvature and distortion curve diagram of a medium wave infrared focal length 2680mm optical system in an embodiment of the present application.

[0066] The reference signs are as follows:

[0067] 1 - primary mirror, 2 - first spectral splitter, 3 - first fold mirror, 4 - second fold mirror, 5 - second spectral splitter, 6 - third fold mirror, 7 - first collimator, 8 - second collimator, 9 - fourth fold 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 fold mirror, 30 - second short wave collimator, 31 - third short wave collimator, 32 - fourth short wave collimator, 33 - fifth short wave collimator, 34 - sixth short wave collimator, 35 - sixth fold mirror, 36 - seventh short wave collimator, 37 - first short wave short focus mirror, 38 - second short wave short focus mirror, 39 - third short wave short focus mirror, 40 - fourth short wave short focus mirror, 41 - fifth short wave short focus mirror, 42 - sixth short wave short focus mirror, 43 - seventh short wave short focus mirror, 44 - first short wave long focus mirror, 45 - second short wave long focus mirror, 46 - third short wave long focus mirror, 47 - fourth short wave long focus mirror, 48 - fifth short wave long focus mirror, 49 - first infrared mirror, 50 - seventh fold 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 - attenuator. DETAILED DESCRIPTION

[0068] In order to make the objects, advantages and features of the present application clearer, the following further describes the present application in conjunction with the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application.

[0069] The embodiment provides a large-aperture three-waveband integrated optical system, which comprises a primary mirror 1, a first spectral splitter 2, a first fold mirror 3, a second fold mirror 4, a second spectral splitter 5, a visible light optical unit, a short-wave optical unit, a third fold mirror 6 and a medium-wave optical unit.

[0070] The first spectral beam splitter 2 is located on the reflection light path of the main mirror 1, and the light beam from the target object at infinity is reflected by the main mirror 1 and then split into two paths by the first spectral beam splitter 2. One path reflects the visible light beam and the short-wave infrared light beam after passing through the first spectral beam splitter 2, and at this time, the main mirror 1 and the first spectral beam splitter 2 form a Cassegrain system. The other path transmits the medium-wave infrared light beam after passing through the first spectral beam splitter 2, and the main mirror 1, the first spectral beam splitter 2 and the third fold mirror 6 thereafter form a Newton system. The first spectral beam splitter 2 is used for one-stage splitting, which avoids the introduction of astigmatism caused by the 45° placement of the parallel-plate spectral beam splitter in the converging light path.

[0071] In the embodiment, the main optical system is composed of the main mirror 1 and the first spectral beam splitter 2. The main mirror 1 is a full mirror with a parabolic surface. The first spectral beam splitter 2 is a convex meniscus germanium lens with a negative focal length towards the object side. The light entrance surface of the first spectral beam splitter 2 is defined as the front surface, and the other surface is the back surface. The front surface is a hyperboloid 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 back surface is a spherical surface and is coated with a multi-layer antireflection film for transmitting medium-wave infrared light.

[0072] The first fold mirror 3, the second fold mirror 4 and the second spectral beam splitter 5 are sequentially arranged along the reflection light path of the first spectral beam splitter 2. The visible light optical unit is located on the reflection light path of the second spectral beam splitter 5, and the short-wave optical unit is located on the transmission light path of the second spectral beam splitter 5. The third fold mirror 6 and the medium-wave optical unit are sequentially arranged along the transmission light path of the first spectral beam splitter 2.

[0073] The second spectral beam splitter 5 is a square prism with no focal length and is made of quartz. The spectral beam splitting film is coated on the splitting surface of the second spectral beam splitter 5 for reflecting visible light and transmitting short-wave infrared light. The second spectral beam splitter 5 is placed in the converging light path, which avoids the introduction of astigmatism caused by the 45° placement of the parallel-plate spectral beam splitter in the converging light path and simplifies the system structure.

[0074] The main mirror 1, the first spectral beam splitter 2, the first fold mirror 3, the second fold mirror 4, the second spectral beam splitter 5 and the visible light optical unit jointly form a visible light optical system for receiving a visible light beam.

[0075] The primary mirror 1, the secondary mirror (the first spectral splitter 2), the first fold mirror 3, the second fold mirror 4, and the spectral prism (the second spectral splitter 5) constitute a primary imaging system in the visible light optical system, the focal length of the primary imaging system is 5574 mm, the relative aperture is 1 / 8.3, and the field of view is 0.60°. The short-focus system is composed of the primary imaging system, the visible light collimating mirror group, and the visible light short-focus objective lens group; and the long-focus system is composed of the primary imaging system, the visible light collimating mirror group, and the visible light long-focus objective lens group. The visible light optical system adopts a secondary imaging system, and zooming is realized by switching the long-focus objective lens group and the short-focus imaging objective lens group in the optical path. The visible light collimating mirror group and the primary image system constitute a front-mounted telescope system with a magnification of 18.58, the visible light short-focus objective lens group has a focal length of 113.02 mm, the visible light long-focus objective lens group has a focal length of 226.05 mm, and thus two-grade zooming visible light optical systems with focal lengths of 2100 mm and 4200 mm are formed.

[0076] The visible light collimating mirror group and the visible light short-focus objective lens group (or the visible light long-focus objective lens group) are parallel light, and a variable diaphragm is arranged, that is, a first variable diaphragm 57 (as shown) is arranged between the eighth collimating mirror 15 and the first short-focus mirror 16 or the first long-focus mirror 23, and the size of the first variable diaphragm 57 is adjusted to realize system dimming; the system adopts an internal focusing mode, and focusing is realized by axially moving the focusing mirror group. Figure 3

[0077] Specifically, the visible light optical unit comprises, in sequence along an optical path, a visible light collimating mirror group, a visible light short-focus objective lens group, and a visible light long-focus objective lens group; wherein the primary mirror 1, the first spectral splitter 2, the first fold mirror 3, the second fold mirror 4, the second spectral splitter 5, the visible light collimating mirror group, and the visible light short-focus objective lens group jointly constitute a visible light short-focus optical system. Figure 1 The visible light short-focus optical system is shown in FIG. 2, the system aperture is Φ670 mm, the system focal length is 2100 mm, the relative aperture is 1 / 3.14, and the field of view is 0.60°.

[0078] The primary mirror 1, the first spectral splitter 2, the first fold mirror 3, the second fold mirror 4, the second spectral splitter 5, the visible light collimating mirror group, and the visible light long-focus objective lens group jointly constitute a visible light long-focus optical system. Figure 2 The visible light long-focus optical system is shown in FIG. 3, the system aperture is Φ670 mm, the system focal length is 4200 mm, the relative aperture is 1 / 6.27, and the field of view is 0.30°.

[0079] As shown in FIG. 1, the visible light optical system comprises a visible light optical unit, a visible light image sensor, and a visible light image processing unit. Figure 3 ​As 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 group includes, in sequence along the optical path, a first short-wavelength focusing mirror 44, a second short-wavelength focusing mirror 45, a third short-wavelength focusing mirror 46, a fourth short-wavelength focusing mirror 47, and a fifth short-wavelength focusing mirror 48. The focal length of the short-wavelength focusing objective group is 144.24 mm, the relative aperture is 1 / 4, and the field of view is 4.88°.

[0094] The first short-wavelength focusing mirror 44 is a positive-power double-convex heavy-crown lens; the second short-wavelength focusing mirror 45 is a negative-power double-concave light-crown lens; the third short-wavelength focusing mirror 46 is a negative-power meniscus heavy-flint lens convex toward the object side; the fourth short-wavelength focusing mirror 47 is a positive-power double-convex fluor-crown lens; and the fifth short-wavelength focusing mirror 48 is a negative-power meniscus heavy-crown lens convex toward the object side.

[0095] The main reflector 1, the first spectral light splitter 2, the third fold mirror 6, and the mid-wave optical unit together form a mid-wave infrared optical system for receiving a mid-wave infrared light beam. Figure 11 FIG. 2 is a schematic diagram of a light path of a mid-wave infrared focusing optical system, which has a system aperture of Φ670 mm, a system focal length of 2680 mm, a relative aperture of 1 / 4, and a field of view of 0.43°.

[0096] In the mid-wave infrared optical system, the main reflector 1, the secondary reflector (the first spectral light splitter 2), the third fold mirror 6, and the first infrared mirror 49 form a mid-wave primary imaging system, which has a focal length of 2600 mm, a relative aperture of 1 / 3.88, and a field of view of 0.44°. The mid-wave primary imaging system, the seventh fold mirror 50, the second infrared mirror 51, the third infrared mirror 52, and the fourth infrared mirror 53 form a mid-wave secondary imaging system. The second infrared mirror 51 is a mid-wave collimating mirror having a focal length of 150 mm. The mid-wave collimating mirror and the mid-wave primary imaging system form a mid-wave front-mounted telescope system, which has a magnification of 17.33 and a projection lens group having a focal length of 24 mm. The mid-wave infrared optical system forms a three-stage imaging optical system including the mid-wave secondary imaging system and the projection lens group. The middle part of the mid-wave secondary imaging system is designed as parallel light, which is conducive to spectral splitting, cold shield matching, and spatial layout of the optical system. High-order aspheric surfaces are used for design, which effectively simplifies the system structure and improves the imaging quality and transmittance of the system. The mid-wave system uses an external focusing method, and focusing is achieved by axially moving a detector.

[0097] Specifically, the mid-wave optical unit includes, in sequence along the optical path, a mid-wave infrared mirror group and a projection lens group. The mid-wave infrared mirror group includes, in sequence along the reflection path of the third fold mirror 6, the first infrared mirror 49, the seventh fold mirror 50, the second infrared mirror 51, the third infrared mirror 52, and the fourth infrared mirror 53.

[0098] As shown in FIG. 1, the mid-wave optical unit includes, in sequence along the optical path, a mid-wave infrared mirror group and a projection lens group. Figure 11As shown, in the embodiment, the first infrared mirror 49 is a convex meniscus ZnS lens with positive focal power facing the image side; the seventh fold mirror 50 is a plane mirror; the second infrared mirror 51 is a convex meniscus Ge lens with positive focal power facing the object side; the third infrared mirror 52 is a convex meniscus Ge lens with negative focal power facing the object side; and the fourth infrared mirror 53 is a convex meniscus Ge lens with positive focal power facing the object side.

[0099] The projection lens group comprises, in sequence along the optical path, a fifth infrared mirror 54, a sixth infrared mirror 55, and a seventh infrared mirror 56; wherein the fifth infrared mirror 54 is a convex meniscus ZnS lens with negative focal power facing the image side; the sixth infrared mirror 55 is a convex meniscus Ge lens with negative focal power facing the object side; and the seventh infrared mirror 56 is a biconvex Si lens with positive focal power.

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

[0101] Table 1: Optical parameters of the lenses (unit: mm)

[0102]

[0103]

[0104]

[0105]

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

[0107]

[0108] wherein z is the sag of the aspherical surface (z coordinate), unit: mm;

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

[0110] k is the quadratic curve constant;

[0111] A is the coefficient of the r 4 term;

[0112] B is the coefficient of the r 6 term;

[0113] C is the coefficient of the r 8 term.

[0114] The unit of the radius of curvature is mm.

[0115] The application provides a large-aperture three-waveband integrated optical system adopting a light splitting mirror spectrum splitting method, and a structure type of three-waveband integrated optical system with a main optical system shared by visible light, short-wave infrared and medium-wave infrared.

[0116] The visible light optical system of the embodiment is applicable to a visible light detector with a resolution of 1920x1080 and a pixel pitch of 10x10 microns.

[0117] Figures 12-16 respectively, a short-wave infrared long-focus 2680mm optical system MTF curve, and a medium-wave infrared focal length 2680mm optical system MTF curve.

[0118] Figures 17-21 respectively, a short-wave infrared long-focus 2680mm optical system MTF curve, and a medium-wave infrared focal length 2680mm optical system MTF curve.

[0119] As can be seen from the figures, the MTF of the visible light long-focus system, the visible light short-focus system, the short-wave infrared short-focus system, the short-wave infrared long-focus system and the medium-wave infrared system is close to the diffraction limit, the optical systems have high imaging quality, and the distortion of each optical system is small, which fully meets the needs of high-precision measurement of targets.

[0120] It should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some or all of the technical features can be replaced by equivalents; and 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 application.

Claims

1. A large aperture three-band integrated optical system, characterized in that: comprising a main mirror (1), a first spectral beam splitter (2), a first fold mirror (3), a second fold mirror (4), a second spectral beam splitter (5), a visible light optical unit, a short wave optical unit, a third fold mirror (6) and a medium wave optical unit; the first spectral beam splitter (2) is located on the reflection light path of the main mirror (1), and the light beam from the target object is reflected by the main mirror (1) and then split into two paths by the first spectral beam splitter (2), one of which reflects the visible light beam and the short wave infrared light beam after passing through the first spectral beam splitter (2), and the other transmits the medium wave infrared light beam after passing through the first spectral beam splitter (2); the first fold mirror (3), the second fold mirror (4) and the second spectral beam splitter (5) are sequentially arranged along the reflection light path of the first spectral beam splitter (2), the visible light optical unit is located on the reflection light path of the second spectral beam splitter (5), and the short wave optical unit is located on the transmission light path of the second spectral beam splitter (5); the third fold mirror (6) and the medium wave optical unit are sequentially arranged along the transmission light path of the first spectral beam splitter (2); the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter (5) and the visible light optical unit jointly form a visible light optical system for receiving a visible light beam; the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter (5) and the short wave optical unit jointly form a short wave infrared optical system for receiving a short wave infrared light beam; the main mirror (1), the first spectral beam splitter (2), the third fold mirror (6) and the medium wave optical unit jointly form a medium wave infrared optical system for receiving a medium wave infrared light beam; the visible light optical unit comprises a visible light collimating mirror group, a visible light short focus objective lens group and a visible light long focus objective lens group which are sequentially arranged along the light path; wherein the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter (5), the visible light collimating mirror group and the visible light short focus objective lens group jointly form a visible light short focus optical system; and the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter (5), the visible light collimating mirror group and the visible light long focus objective lens group jointly form a visible light long focus optical system; the short wave optical unit comprises a short wave collimating mirror group, a short wave short focus objective lens group and a short wave long focus objective lens group which are sequentially arranged along the light path; wherein the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter, the short wave collimating mirror group and the short wave short focus objective lens group jointly form a short wave short focus infrared optical system; and the main mirror (1), the first spectral beam splitter (2), the first fold mirror (3), the second fold mirror (4), the second spectral beam splitter (5), the short wave collimating mirror group and the short wave long focus objective lens group jointly form a short wave long focus infrared optical system. ​ ​ ​ ​ ​ ​ ​ ​ The middle wave optical unit comprises a middle wave infrared lens group and a projection lens group arranged in sequence along an optical path. 2.The large-aperture three-waveband integrated optical system according to claim 1, characterized in that: The visible light collimating lens group comprises a first collimating lens (7), a second collimating lens (8), a fourth fold mirror (9), a third collimating lens (10), a fourth collimating lens (11), a fifth collimating lens (12), a sixth collimating lens (13), a seventh collimating lens (14), and an eighth collimating lens (15) arranged in sequence along a reflection optical path of the second spectrum splitting mirror (5) ; The first collimating lens (7) is a negative focal length convex meniscus meniscus lens; the second collimating lens (8) is a positive focal length double-convex optical crystal; the fourth fold mirror (9) is a plane mirror; the third collimating lens (10) is a negative focal length convex meniscus meniscus lens; the fourth collimating lens (11) is a negative focal length double-concave light meniscus lens; the fifth collimating lens (12) is a positive focal length double-convex heavy meniscus lens; the sixth collimating lens (13) is a negative focal length convex meniscus meniscus lens; the seventh collimating lens (14) is a positive focal length convex meniscus meniscus lens; and the eighth collimating lens (15) is a positive focal length convex meniscus meniscus lens. 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) arranged in sequence along an optical path; The first short-focus lens (16) is a negative focal length convex meniscus meniscus lens; the second short-focus lens (17) is a positive focal length double-convex fluorine meniscus lens; the third short-focus lens (18) is a negative focal length double-concave light meniscus lens; the fourth short-focus lens (19) is a positive focal length double-convex optical crystal; the fifth short-focus lens (20) is a negative focal length convex meniscus meniscus lens; the sixth short-focus lens (21) is a positive focal length convex meniscus fluorine meniscus lens; and the seventh short-focus lens (22) is a negative focal length convex meniscus meniscus lens. The visible light long-focus objective lens group comprises a first long-focus lens (23), a second long-focus lens (24), a third long-focus lens (25), a fourth long-focus lens (26), and a fifth long-focus lens (27) ; The first long-focus lens (23) is a positive focal length double-convex optical crystal; the second long-focus lens (24) is a negative focal length convex meniscus light meniscus lens; the third long-focus lens (25) is a negative focal length convex meniscus meniscus lens; the fourth long-focus lens (26) is a negative focal length convex meniscus heavy meniscus lens; and the fifth long-focus lens (27) is a positive focal length convex meniscus heavy meniscus lens. 3.The large-aperture three-waveband integrated optical system according to claim 2, characterized in that: The visible light optical unit is an internal focusing type, and focusing is achieved by axially moving a focusing lens group composed of a third collimating mirror (10), a fourth collimating mirror (11), and a fifth collimating mirror (12).

4. The large-aperture three-waveband integrated optical system according to claim 1, characterized in that: The short-wave collimating lens group comprises, in order along a transmission light path of the first spectral splitter (2), a first short-wave collimating lens (28), a fifth fold mirror (29), a second short-wave collimating lens (30), a third short-wave collimating lens (31), a fourth short-wave collimating lens (32), a fifth short-wave collimating lens (33), a sixth short-wave collimating lens (34), a sixth fold mirror (35), and a seventh short-wave collimating lens (36); The first short-wave collimating lens (28) is a positive-power double-convex heavy flint lens; the fifth fold mirror (29) is a plane mirror; the second short-wave collimating lens (30) is a negative-power meniscus heavy flint lens convex toward the object side; the third short-wave collimating lens (31) is a negative-power double-concave light crown lens; the fourth short-wave collimating lens (32) is a positive-power double-convex heavy phosphor crown lens; the fifth short-wave collimating lens (33) is a negative-power meniscus heavy flint lens convex toward the image side; the sixth short-wave collimating lens (34) is a positive-power meniscus heavy phosphor crown lens convex toward the image side; the sixth fold mirror (35) is a plane mirror; and the seventh short-wave collimating lens (36) is a positive-power double-convex heavy flint lens; The short-wave short-focus objective lens group comprises, in order along the light path, a first short-wave short-focus lens (37), a second short-wave short-focus lens (38), a third short-wave short-focus lens (39), a fourth short-wave short-focus lens (40), a fifth short-wave short-focus lens (41), a sixth short-wave short-focus lens (42), and a seventh short-wave short-focus lens (43); The first short-wave short-focus lens (37) is a negative-power meniscus heavy flint lens convex toward the image side; the second short-wave short-focus lens (38) is a positive-power meniscus fluor crown lens convex toward the object side; the third short-wave short-focus lens (39) is a negative-power meniscus light crown lens convex toward the object side; the fourth short-wave short-focus lens (40) is a positive-power double-convex optical crystal; the fifth short-wave short-focus lens (41) is a negative-power meniscus heavy flint lens convex toward the image side; the sixth short-wave short-focus lens (42) is a positive-power double-convex heavy phosphor crown lens; and the seventh short-wave short-focus lens (43) is a negative-power meniscus heavy flint lens convex toward the object side; The short-wave long-focus objective lens group comprises, in order along the light path, a first short-wave long-focus lens (44), a second short-wave long-focus lens (45), a third short-wave long-focus lens (46), a fourth short-wave long-focus lens (47), and a fifth short-wave long-focus lens (48); The first short-wavelength focus lens (44) is a positive-power double-convex heavy phosphor lens; the second short-wavelength focus lens (45) is a negative-power double-concave light phosphor lens; the third short-wavelength focus lens (46) is a negative-power meniscus heavy flint lens convex to the object side; the fourth short-wavelength focus lens (47) is a positive-power double-convex fluorophor lens; and the fifth short-wavelength focus lens (48) is a negative-power meniscus heavy phosphor lens convex to the object side.

5. The large-aperture three-waveband integrated optical system according to claim 1, characterized in that: the middle-wave infrared lens group comprises, in sequence along the reflection light path of the third folding mirror (6), a first infrared lens (49), a seventh folding mirror (50), a second infrared lens (51), a third infrared lens (52), and a fourth infrared lens (53); the first infrared lens (49) is a positive-power meniscus ZnS lens convex to the image side; the seventh folding mirror (50) is a plane mirror; the second infrared lens (51) is a positive-power meniscus Ge lens convex to the object side; the third infrared lens (52) is a negative-power meniscus Ge lens convex to the object side; and the fourth infrared lens (53) is a positive-power meniscus Ge lens convex to the object side; the projection lens group comprises, in sequence along the light path, a fifth infrared lens (54), a sixth infrared lens (55), and a seventh infrared lens (56); the fifth infrared lens (54) is a negative-power meniscus ZnS lens convex to the image side; the sixth infrared lens (55) is a negative-power meniscus Ge lens convex to the object side; and the seventh infrared lens (56) is a positive-power double-convex Si lens.

6. The large-aperture three-waveband integrated optical system according to any one of claims 1 to 5, characterized in that: the main reflector (1) is a full reflector with a parabolic surface; the first spectral splitter (2) is a negative-power meniscus Ge lens convex to the object side; the light entrance surface of the first spectral splitter (2) is defined as its front surface, and the other surface is defined as its back surface; the front surface is a hyperboloid and is coated with a spectral splitting film for reflecting visible light and short-wave infrared light and transmitting middle-wave infrared light; and the back surface is a spherical surface and is coated with a multilayer antireflection film for transmitting middle-wave infrared light; the second spectral splitter (5) is a positive cube without optical power, and the splitting surface is coated with a splitting film for reflecting visible light and transmitting short-wave infrared light.

7. The large-aperture three-waveband integrated optical system according to claim 6, characterized in that: the second spectral splitter (5) is made of quartz.

8. The large-aperture three-waveband integrated optical system according to claim 2, 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).

9. The large-aperture three-waveband integrated optical system according to claim 4, characterized in that: a second variable diaphragm (58) is arranged between the seventh short-wave collimating lens (36) and the first short-wave short-focus lens (37) or the first short-wavelength focus lens (44). The light emitting ends of the seventh short-wave short-focus mirror (43) and the fifth short-wave long-focus mirror (48) are respectively provided with an attenuation sheet (59).

Images