Infrared, laser and millimeter wave three-mode composite detection seeker optical system

Abstract

The invention discloses an infrared, laser and millimeter wave three-mode composite detection seeker optical system, and belongs to the field of optical imaging seekers. The system is coaxially provided with a fairing, a secondary reflector, a primary reflector, a millimeter wave phased array radar and a right-angle beam splitter prism along an optical axis from an object space to an image space. The millimeter wave phased array radar is located between the main reflector and the right-angle beam splitter prism, and the center of the millimeter wave phased array radar is provided with a hole allowing infrared and laser rays to pass. The right-angle beam splitter prism is a cube formed by splicing two triangular prisms through an optical cement method, so that infrared light is transmitted and then propagated in the original direction, and an included angle of 90 degrees is formed between the propagation direction and the incident direction after laser light is reflected. The infrared light path is imaged on an infrared subsystem image plane through the infrared imaging lens group; a laser light path is reflected by the right-angle beam splitter prism and then is focused to the four-quadrant detector through the laser convergent lens group. According to the invention, the light energy utilization rate and the remote target detection capability can be improved, and all-weather, anti-interference and high-integration accurate detection can be realized.

Description

Technical Field

[0001] This invention relates to the field of optical imaging seekers, specifically to an optical system for a three-mode composite detection seeker that combines infrared, laser, and millimeter-wave imaging. Background Technology

[0002] As a core component of precision-guided weapons, the performance of the seeker determines the weapon's tracking, identification, and acquisition capabilities. Currently, the mainstream guidance methods include infrared imaging guidance, laser guidance, and radar guidance.

[0003] Infrared guidance technology utilizes the strong infrared radiation of the target itself to enable missiles to automatically aim at, track, and approach the target until it hits. Among various precision guidance technologies, infrared guidance occupies an important position in the development of modern weaponry due to its advantages such as high guidance accuracy, strong anti-jamming capability, good concealment, and high cost-effectiveness.

[0004] Laser guidance uses a lidar system to emit a laser beam that illuminates the target. The reflected laser light is then focused and received by a detector, from which information such as spectral amplitude and phase can be extracted. Combined with multi-sensor information fusion processing, this enables precise target identification. Laser guidance also features high precision and strong anti-interference capabilities.

[0005] Compared with optical seekers such as infrared and laser, millimeter-wave seekers have a stronger ability to penetrate fog, smoke and dust, and have the advantages of all-weather (except heavy rain) and all-time operation. Moreover, their anti-interference and anti-stealth capabilities are superior to other microwave seekers.

[0006] Multimode composite guidance technology is a key research focus for countries worldwide. Its core principle is achieving optoelectronic complementarity: by leveraging the precise detection advantages of different wavebands for targets and their localized areas, it overcomes the limitations of single-waveband systems, comprehensively utilizing the strengths of each band to accurately transmit the target's precise location to the backend control system. This technology can improve upon the weaknesses of single-mode optical systems, achieving performance complementarity and mitigating shortcomings, ultimately enabling all-weather combat and precise target positioning.

[0007] In the prior art, Chinese patent application number 202010936145.8 discloses a tri-mode seeker optical system with a common aperture for infrared, laser, and millimeter-wave wavelengths, consisting of a head cover, primary mirror, secondary mirror, feed source, waveguide, millimeter-wave transceiver module, infrared channel, and laser channel. Its main drawbacks include: the millimeter-wave feed source is located between the secondary mirror and the head cover, resulting in significant obstruction; the use of a flat beam splitter easily introduces asymmetric astigmatism, making assembly and adjustment difficult, and installation errors significantly affect the imaging quality of subsequent optical systems; and the transmission eyepiece group has low transmittance in both the infrared and laser bands. Summary of the Invention

[0008] This invention provides an optical system for a three-mode composite detection seeker that integrates infrared, laser, and millimeter-wave technologies, improving light energy utilization and long-range target detection capabilities to achieve all-weather, anti-interference, long-range, and highly integrated precision detection.

[0009] To achieve the above objectives, the technical solution adopted by this invention is: an infrared, laser, and millimeter-wave tri-mode composite detection seeker optical system, comprising: a radome, a secondary reflector, a primary reflector, a millimeter-wave phased array radar, and a right-angle beam splitter arranged coaxially along the optical axis from the object side to the image side; the reflecting surface of the primary reflector faces the object side, and it has an opening at its center; the reflecting surface of the secondary reflector faces the direction of the reflected light from the primary reflector. The millimeter-wave phased array radar is located between the main reflector and the right-angle beam splitter, with an opening in the center for infrared and laser light to pass through, and is also used to receive external millimeter-wave rays passing through the radome, secondary reflector and main reflector. The right-angle beam splitter is composed of two triangular prisms joined together to form a cube using an optical adhesive method, which allows infrared light to be transmitted along its original direction and laser light to be reflected at 90°. The optical system also includes an infrared imaging lens group disposed on the transmission optical path of the right-angle beam splitter, and a laser converging lens group disposed on the reflection optical path of the right-angle beam splitter. The infrared imaging lens group includes a first meniscus positive lens, a first meniscus negative lens and a second meniscus positive lens arranged sequentially along the optical path, used to image infrared light onto the image plane of the infrared subsystem. The laser converging lens group includes a plano-convex positive lens, a third meniscus positive lens, and a fourth meniscus positive lens arranged sequentially along the optical path, used to focus the laser onto the photosensitive surface of the four-quadrant detector.

[0010] Furthermore, the concave surface of the fairing is arranged facing the right-angle beam splitter, the convex surfaces of the first meniscus positive lens, the first meniscus negative lens, the second meniscus positive lens, the third meniscus positive lens, and the fourth meniscus positive lens are arranged facing the right-angle beam splitter, and the plane of the plano-convex positive lens is arranged facing the right-angle beam splitter.

[0011] Furthermore, the reflecting surface of the primary reflector is a parabolic surface, and the reflecting surface of the secondary reflector is a quadratic surface with a quadratic surface coefficient k=11.289.

[0012] Furthermore, the obstruction ratio of the catadioptric system composed of the primary reflector and the secondary reflector is 0.5.

[0013] Furthermore, the optical bonding method for the right-angle beam splitter is as follows: the surfaces of two polished triangular prisms are bonded together by pressure using molecular attraction, without the use of any adhesive.

[0014] Furthermore, the millimeter-wave phased array radar adopts a planar microstrip patch array antenna, and the diameter of the millimeter-wave phased array radar is comparable to the diameter of the main reflector.

[0015] Furthermore, the fairing is made of multispectral zinc sulfide, the primary and secondary reflectors are both made of fused silica, the right-angle beam splitter is made of zinc sulfide, the first meniscus positive lens is made of single-crystal germanium, the first meniscus negative lens is made of zinc selenide, the second meniscus positive lens is made of single-crystal germanium, and the plano-convex positive lens, the third meniscus positive lens, and the fourth meniscus positive lens are all made of H-ZLAF4LA.

[0016] Furthermore, each lens satisfies the following condition: First meniscus positive lens: 0.7≤f6 / f≤0.8, where f is the focal length of the optical system and f6 is the focal length of the first meniscus positive lens; First meniscus negative lens: -0.6≤f7 / f≤-0.5, where f7 is the focal length of the first meniscus negative lens; Second meniscus positive lens: 0.2≤f8 / f≤0.3, where f8 is the focal length of the second meniscus positive lens; Plano-convex positive lens: 0.8≤f 10 / f≤0.9, where f 10 The focal length of the plano-convex positive lens; Third crescent-shaped positive lens: 0.6≤f 11 / f≤0.7, where f 11 The focal length of the third meniscus positive lens; Fourth meniscus positive lens: 4.0≤f 12 / f≤4.2, where f 12 This is the focal length of the fourth meniscus positive lens.

[0017] Furthermore, the image-side surface of both the first meniscus negative lens and the image-side surface of the second meniscus positive lens 8 are aspherical.

[0018] Furthermore, the technical parameters of the infrared subsystem are as follows: operating wavelength 8μm~12μm, F#: 1.05, focal length: 70mm, field of view: 6.28°×5.03°, where F# is calculated by the formula f / D, f is the focal length of the optical system, and D is the diameter of the entrance pupil; the technical parameters of the laser subsystem are as follows: operating wavelength 1.064μm, focal length 85mm, field of view 6°.

[0019] The beneficial effects of this invention are: (1) The present invention places the millimeter-wave phased array radar behind the main mirror and in front of the right-angle beam splitter. The diameter of the millimeter-wave phased array radar is comparable to that of the main mirror. This layout can effectively increase the array size and realize long-distance detection. The central opening allows infrared and laser beams to pass through without obstruction, completely avoiding the blockage of the infrared / laser light path by the millimeter-wave components, thereby improving the light energy utilization rate of the infrared and laser subsystems and ensuring that the weak radiation signal of the distant target can be effectively captured.

[0020] (2) The optical system of the present invention effectively corrects various aberrations by rationally allocating the optical power of each lens, coordinating the optical materials of the lenses, and optimizing the spacing between each lens. The F number of the infrared system is optimized to 1.05, realizing a large relative aperture design, greatly improving the light-gathering ability, and effectively improving the light energy utilization rate, thereby enabling stable detection and identification of distant targets.

[0021] (3) This invention uses a right-angle beam splitter to achieve beam splitting in the infrared and laser bands. It is spliced ​​by optical adhesive method (without adhesive) and fixed by molecular attraction. This solves the technical problem that the adhesive used in traditional optical systems cannot transmit long-wave infrared light in the 8μm to 12μm band. The optical adhesive method right-angle beam splitter does not introduce aberrations, is simple to assemble and adjust, and ensures the clarity of the infrared subsystem for imaging distant targets.

[0022] (4) The three-mode composite seeker optical system adopts a common aperture design, which is conducive to reducing the system size and reducing the platform scanning hardware. The three sensors are located on the same platform, and the optical axis and electrical axis coincide with each other, which is conducive to maintaining the calibration of the aiming line. At the same time, the optical aperture area of ​​laser and infrared and the aperture efficiency of millimeter-wave radar antenna are optimized.

[0023] (5) The millimeter-wave phased array radar uses a planar microstrip patch array antenna with a central opening to allow infrared and laser light to pass through. The laser and infrared signals are then received separately by splitting the beam behind the radar antenna. The split laser and infrared systems are transmission-type, which is easy to design and adjust. The planar array antenna used in the millimeter-wave system has good sidelobe and clutter suppression performance. Attached Figure Description

[0024] Figure 1 This is the optical path diagram of the optical system of the present invention; Figure 2 This is a transfer function diagram of the infrared subsystem of the present invention; Figure 3 This is a dot diagram of the infrared subsystem of the present invention; Figure 4 This is a field curvature and distortion curve diagram of the infrared subsystem of the present invention; Figure 5 This is a diagram of the laser optical system of the present invention after defocusing.

[0025] Among them, 1 is the fairing, 2 is the main reflector, 3 is the secondary reflector, 4 is the millimeter-wave phased array radar, 5 is the right-angle beam splitter, 6 is the first meniscus positive lens, 7 is the first meniscus negative lens, 8 is the second meniscus positive lens, 9 is the infrared subsystem image plane, 10 is the plano-convex positive lens, 11 is the third meniscus positive lens, 12 is the fourth meniscus positive lens, and 13 is the receiving photosensitive surface of the four-quadrant detector. Detailed Implementation

[0026] To make the above-mentioned features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings. In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicating directions or positional relationships, are only used in conjunction with the accompanying drawings. Figure 1 Correspondingly, this is for the purpose of describing the invention and does not indicate or imply that the device or element referred to must have a specific orientation. The terms "first," "second," and "third" are used for descriptive purposes only and refer to the order in which lenses of this type appear, and should not be construed as indicating or implying relative importance.

[0027] Throughout the entire specification, the same reference numerals refer to the same components. The accompanying drawings are for illustrative purposes only and are not drawn to scale.

[0028] As is common knowledge, the direction closer to object space is called the object side, and the direction closer to image space is called the image side. From the object side to the image side, the two sides of the lens are, respectively, the incident surface and the exit surface. The object side refers to the side where the light rays enter, and the image side refers to the side where they exit. "From the object side to the image side along the optical axis" means... Figure 1 The direction from left to right. Of the two surfaces of each lens, the surface facing the object is called the object surface, and the surface facing the image is called the image surface.

[0029] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0030] like Figure 1The optical system of an infrared, laser, and millimeter-wave tri-mode composite detection seeker shown includes the following components coaxially arranged from the object side to the image side: a radome 1, a secondary reflector 3, a primary reflector 2, a millimeter-wave phased array radar 4, a right-angle beam splitter 5, a first meniscus positive lens 6, a first meniscus negative lens 7, and a second meniscus positive lens 8. The millimeter-wave phased array radar 4 is located between the primary reflector 2 and the right-angle beam splitter 5, with a central opening allowing infrared and laser light to pass through. The right-angle beam splitter 5 separates the infrared and laser light. After passing through the right-angle beam splitter 5, the infrared light path is sequentially imaged onto the infrared subsystem image plane 9 by the coaxially arranged first meniscus positive lens 6, first meniscus negative lens 7, and second meniscus positive lens 8. After being reflected by the right-angle beam splitter 5, the propagation direction forms a 90° angle with the incident direction. Then, it is focused sequentially by the coaxially arranged plano-convex positive lens 10, the third meniscus positive lens 11, and the fourth meniscus positive lens 12 onto the photosensitive surface 13 of the four-quadrant detector.

[0031] In specific implementation, the fairing 1 is a spherical fairing, with its front and rear surfaces being concentric spheres. Its thickness is the difference between the radii of curvature of the front and rear surfaces. The radius of curvature of the front surface is 100mm, and the radius of curvature of the rear surface is 95mm, with a thickness of 5mm. The concave surface of the fairing 1 faces the right-angle beam splitter prism 5. The convex surfaces of the first meniscus positive lens 6, the first meniscus negative lens 7, the second meniscus positive lens 8, the third meniscus positive lens 11, and the fourth meniscus positive lens 12 face the right-angle beam splitter prism 5. The planar surface of the plano-convex positive lens 10 faces the right-angle beam splitter prism 5.

[0032] The primary reflector 2 has a parabolic reflector surface, and the secondary reflector 3 has a quadratic reflector surface with a quadratic coefficient k = 11.289. The primary reflector 2 is located between the secondary reflector 3 and the millimeter-wave phased array radar 4, with its reflector surface facing the object side. The secondary reflector 3 is located between the radome 1 and the primary reflector 2, with its reflector surface facing the direction of the reflected light from the primary reflector 2. Infrared and laser beams are transmitted through the radome 1 and then reflected by the primary reflector 2 to the secondary reflector 3. The primary reflector 2 has a central opening with a diameter of 85 mm, and the secondary reflector 3 has a diameter of 42 mm. The obstruction ratio of the catadioptric system formed by the primary reflector 2 and the secondary reflector 3 is 0.5. After passing through the fairing 1, the millimeter-wave rays directly pass through the central region of the secondary reflector 3 and continue to propagate toward the main reflector 2. They then shine directly along the optical axis of the system to the central opening of the main reflector 2, which is directly opposite the receiver of the millimeter-wave phased array radar 4.

[0033] The right-angle beam splitter prism 5 is composed of two triangular prisms joined together to form a cube using an optical adhesive method. Infrared light is transmitted and propagates along its original direction, while laser light, after reflection, propagates at a 90° angle to the incident direction; that is, the outgoing direction forms a 90° angle with the incident direction. Specifically, the right-angle beam splitter prism 5 uses an optical adhesive method, bonding two clean, smooth, and identically shaped triangular prism surfaces together under pressure. The bonding relies on the attractive force between the molecules on the two polished triangular prism surfaces, without using any adhesive.

[0034] Preferably, the antenna portion of the millimeter-wave phased array radar 4 is in the form of a flat panel, specifically a microstrip patch array antenna. The millimeter-wave phased array radar 4 features a central opening to allow infrared and laser light to pass through. Furthermore, the diameter of the millimeter-wave phased array radar 4 is approximately the same as the diameter of the main reflector 2, and the diameter of the central opening of the millimeter-wave phased array radar 4 is also approximately the same as the diameter of the central opening of the main reflector 2.

[0035] In this embodiment, the fairing 1 is made of multispectral zinc sulfide (CVD ZNS), the primary reflector 2 is made of fused silica (SILICA), the secondary reflector 3 is made of fused silica (SILICA), the right-angle beam splitter 5 is made of zinc sulfide (ZNS), the first meniscus positive lens 6 is made of single-crystal germanium (Ge), the first meniscus negative lens 7 is made of zinc selenide (ZNSE), the second meniscus positive lens 8 is made of single-crystal germanium (Ge), the plano-convex positive lens 10 is made of H-ZLAF4LA, the third meniscus positive lens 11 is made of H-ZLAF4LA, and the fourth meniscus positive lens 12 is made of H-ZLAF4LA.

[0036] Preferably, the first meniscus positive lens 6 satisfies the following condition: 0.7≤f6 / f≤0.8, where f is the focal length of the optical system and f6 is the focal length of the first meniscus positive lens; The first meniscus negative lens 7 satisfies the following condition: -0.6≤f7 / f≤-0.5, where f is the focal length of the optical system and f7 is the focal length of the first meniscus negative lens; The second meniscus positive lens 8 satisfies the following condition: 0.2≤f8 / f≤0.3, where f is the focal length of the optical system and f8 is the focal length of the second meniscus positive lens; The plano-convex positive lens 10 satisfies the following condition: 0.8 ≤ f 10 / f≤0.9, where f is the focal length of the optical system, f 10 The focal length of the plano-convex positive lens; The third meniscus positive lens 11 satisfies the following condition: 0.6 ≤ f 11 / f≤0.7, where f is the focal length of the optical system, f 11 The focal length of the third meniscus positive lens; The fourth meniscus positive lens 12 satisfies the following condition: 4.0 ≤ f 12 / f≤4.2, where f is the focal length of the optical system, f 12 This is the focal length of the fourth meniscus positive lens.

[0037] The light transmission path of the infrared subsystem of the optical system of the present invention is as follows: infrared light in the 8μm to 12μm band emitted by infrared radiation from the external scene passes through the spherical rectifier 1 and reaches the primary reflector 2. After being reflected by the primary reflector 2, it reaches the secondary reflector 3. After being reflected by the secondary reflector 3, it passes through the central hole of the millimeter-wave phased array radar 4 and reaches the right-angle beam splitter 5. After passing through the right-angle beam splitter 5, it reaches the first meniscus positive lens 6. After being converged by the first meniscus positive lens 6, it reaches the first meniscus negative lens 7. After being diverged by the first meniscus negative lens 7, it reaches the second meniscus positive lens 8. After being converged by the second meniscus positive lens 8, it is imaged on the image plane 9 of the infrared subsystem.

[0038] The light transmission path of the laser subsystem of the optical system of the present invention is as follows: the 1.064μm band laser light reflected from the external scene passes through the spherical rectifier 1 and reaches the main reflector 2. After being reflected by the main reflector 2, it reaches the secondary reflector 3. After being reflected by the secondary reflector 3, it passes through the central hole of the millimeter-wave phased array radar 4 and reaches the right-angle beam splitter 5. After being reflected by the right-angle beam splitter 5, it reaches the plano-convex positive lens 10. After being converged by the plano-convex positive lens 10, it reaches the third meniscus positive lens 11. After being converged by the third meniscus positive lens 11, it reaches the fourth meniscus positive lens 12. After being converged by the fourth meniscus positive lens 12, it reaches the photosensitive surface 13 of the four-quadrant detector.

[0039] The light transmission path of the radar subsystem of the optical system of the present invention is as follows: the millimeter-wave rays reflected by the external scenery pass through the spherical radome 1, the secondary reflector 3, and the primary reflector 2 before reaching the millimeter-wave phased array radar 4.

[0040] Table 1 shows the technical specifications of the infrared subsystem of this invention. The F-number of the F# optical system is calculated as f / D, where f is the focal length of the optical system and D is the diameter of the entrance pupil.

[0041] Table 1 Technical Specifications of the Infrared Subsystem of the Invention Table 2 shows the technical specifications of the laser subsystem of this invention.

[0042] Table 2 Technical Specifications of the Laser Subsystem of the Invention Tables 3 and 4 list detailed data for embodiments of the optical system of the present invention, including the surface shape, radius of curvature, thickness, and material of each lens. The units for the radius of curvature and thickness of the lens are mm. The radius of curvature of spherical and aspherical surfaces refers to the radius of curvature at the intersection of the lens surface and the optical axis. The "radius" in Tables 3 and 4 represents the radius of curvature of the surface. Its sign is determined by taking the intersection of the surface and the principal optical axis as the starting point and the center of the surface as the ending point. If the direction of the connecting line is the same as the direction of light propagation, it is positive; otherwise, it is negative. If the surface is planar, the radius of curvature is infinite. The "thickness" in Tables 3 and 4 gives the distance between two adjacent surfaces on the optical axis. Its sign is determined by taking the vertex of the current surface as the starting point and the vertex of the next surface as the ending point. If the direction of the connecting line is the same as the direction of light propagation, it is positive; otherwise, it is negative. If the material between the two surfaces is infrared material, the thickness represents the lens thickness; if there is no material between the two surfaces, it represents the air gap between the two lenses.

[0043] Table 3 Detailed data of the infrared subsystem in the embodiments of the present invention Table 4 Detailed data of the laser subsystem in the embodiments of the present invention The infrared, laser, and millimeter-wave three-mode composite detection seeker optical system described above has aspherical surfaces on the surface of the first meniscus negative lens 7 facing the image side (i.e., the exit surface) and the surface of the second meniscus positive lens 8 facing the image side (i.e., the exit surface).

[0044] Furthermore, the surface equations of the above-mentioned aspherical surfaces are as follows: Where z is the distance vector from the vertex of the aspherical surface at a height of r along the optical axis, c is the curvature, c=1 / R, R represents the radius of curvature of the lens surface, r is the radial coordinate perpendicular to the optical axis, k is the quadratic curve constant, A is the fourth-order aspherical coefficient, B is the sixth-order aspherical coefficient, C is the eighth-order aspherical coefficient, and D is the tenth-order aspherical coefficient.

[0045] Table 5 lists the aspherical coefficients of the image-side surface (exit surface) of the first meniscus negative lens 7 and the image-side surface (exit surface) of the second meniscus positive lens 8 according to the present invention. The table uses scientific notation; for example, 4.63665e-007 represents 4.63665 × 10⁻⁶. -7 .

[0046] Table 5 Aspherical coefficients of the optical system in the embodiments of the present invention After simulation using optical design software, such as Figure 2As shown, the transfer function of a long-wavelength uncooled detector with a pixel size of 12µm and a pixel count of 640×512 at a spatial frequency of 42lp / mm is greater than 0.25; Figure 3 As shown, the diameter of the diffuse spot in the infrared optical system is smaller than the diameter of the Airy disk; Figure 4 The figure shows the field curvature and distortion curves of the optical system. As can be seen from the figure, the edge field distortion of the infrared system is less than 3.5%. Figure 5 The image shows the light spot after the laser optical system is defocused. As can be seen from the image, when the photosensitive surface is adjusted to a suitable defocus position, the light spot in the linear field of view is already very uniform at the suitable defocus position.

[0047] Finally, it should be noted that any parts of this invention not described in detail are prior art. Those skilled in the art will understand that the above descriptions are merely preferred embodiments of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. An optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave), characterized in that, The system includes the following components arranged coaxially from the object side to the image side along the optical axis: a fairing (1), a secondary reflector (3), a primary reflector (2), a millimeter-wave phased array radar (4), and a right-angle beam splitter (5); the reflecting surface of the primary reflector (2) faces the object side and has an opening at its center; the reflecting surface of the secondary reflector (3) faces the direction of the reflected light from the primary reflector (2); The millimeter-wave phased array radar (4) is located between the main reflector (2) and the right-angle beam splitter (5), and its center is provided with an opening for infrared and laser light to pass through, and is also used to receive external millimeter-wave rays passing through the radome (1), the secondary reflector (3) and the main reflector (2). The right-angle beam splitter (5) is formed by splicing two triangular prisms into a cube using optical adhesive, so that infrared light is transmitted along the original direction and laser light is reflected by 90°. The optical system also includes an infrared imaging lens group disposed on the transmission optical path of the right-angle beam splitter (5) and a laser converging lens group disposed on the reflection optical path of the right-angle beam splitter (5). The infrared imaging lens group includes a first meniscus positive lens (6), a first meniscus negative lens (7), and a second meniscus positive lens (8) arranged sequentially along the optical path, for imaging infrared light onto the infrared subsystem image plane (9). The laser converging lens group includes a plano-convex positive lens (10), a third meniscus positive lens (11) and a fourth meniscus positive lens (12) arranged sequentially along the optical path, which are used to focus the laser onto the photosensitive surface (13) of the four-quadrant detector.

2. The infrared, laser, and millimeter-wave tri-mode composite detection seeker optical system according to claim 1, characterized in that, The concave surface of the fairing (1) is arranged facing the right-angle beam splitter (5), the convex surfaces of the first meniscus positive lens (6), the first meniscus negative lens (7), the second meniscus positive lens (8), the third meniscus positive lens (11), and the fourth meniscus positive lens (12) are arranged facing the right-angle beam splitter (5), and the planar surface of the plano-convex positive lens (10) is arranged facing the right-angle beam splitter (5).

3. The optical system for a three-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, The primary reflector (2) has a parabolic reflector surface, and the secondary reflector (3) has a quadric reflector surface with a quadric coefficient k = 11.

289.

4. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1 or 3, characterized in that, The obstruction ratio of the catadioptric system composed of the primary reflector (2) and the secondary reflector (3) is 0.

5.

5. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, The optical bonding method for the right-angle beam splitter (5) is as follows: the surfaces of the two polished triangular prisms are bonded together by pressure due to molecular attraction, without the use of any adhesive.

6. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, The millimeter-wave phased array radar (4) adopts a microstrip patch array antenna in the form of a flat panel, and the diameter of the millimeter-wave phased array radar (4) is comparable to the diameter of the main reflector (2).

7. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, The fairing (1) is made of multispectral zinc sulfide, the primary reflector (2) and the secondary reflector (3) are both made of fused silica, the right-angle beam splitter (5) is made of zinc sulfide, the first meniscus positive lens (6) is made of single-crystal germanium, the first meniscus negative lens (7) is made of zinc selenide, the second meniscus positive lens (8) is made of single-crystal germanium, and the plano-convex positive lens (10), the third meniscus positive lens (11) and the fourth meniscus positive lens (12) are all made of H-ZLAF4LA.

8. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, Each lens satisfies the following conditions: First meniscus positive lens (6): 0.7≤f6 / f≤0.8, where f is the focal length of the optical system and f6 is the focal length of the first meniscus positive lens; First meniscus negative lens (7): -0.6≤f7 / f≤-0.5, where f7 is the focal length of the first meniscus negative lens; Second meniscus positive lens (8): 0.2≤f8 / f≤0.3, where f8 is the focal length of the second meniscus positive lens; Plano-convex positive lens (10): 0.8≤f 10 / f≤0.9, where f 10 The focal length of the plano-convex positive lens; Third crescent-shaped positive lens (11): 0.6≤f 11 / f≤0.7, where f 11 The focal length of the third meniscus positive lens; Fourth meniscus positive lens (12): 4.0≤f 12 / f≤4.2, where f 12 This is the focal length of the fourth meniscus positive lens.

9. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 8, characterized in that, The image-side surfaces of the first meniscus negative lens (7) and the second meniscus positive lens (8) are both aspherical.

10. The optical system for a tri-mode composite detection seeker (infrared, laser, millimeter-wave) according to claim 1, characterized in that, The technical parameters of the infrared subsystem are: operating wavelength 8μm~12μm, F#: 1.05, focal length: 70mm, field of view: 6.28° × 5.03°, where, The formula for calculating F# is f / D, where f is the focal length of the optical system and D is the diameter of the entrance pupil. The technical parameters of the laser subsystem are: operating wavelength 1.064μm, focal length 85mm, and field of view 6°.

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