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

Abstract

The application discloses an infrared, laser and millimeter wave three-mode composite detection and guiding head optical system and belongs to the field of optical imaging guiding heads. The system is coaxially provided with a fairing, a secondary mirror, a primary mirror, a millimeter wave phased array radar and a right-angle light splitting prism along an optical axis from an object side to an image side; the millimeter wave phased array radar is located between the primary mirror and the right-angle light splitting prism, and a center hole thereof allows infrared and laser light to pass through; the right-angle light splitting prism is formed by splicing two triangular prisms into a cube through optical cementing, so that infrared light is transmitted along an original direction after transmission, and laser light is reflected and propagates in a direction which forms a 90-degree angle with an incident direction. An infrared light path is imaged on an infrared subsystem image plane through an infrared imaging lens; and a laser light path is focused to a four-quadrant detector through a laser converging lens after being reflected by the right-angle light splitting prism. The application can improve light energy utilization and long-distance target detection capability, and realizes all-weather, anti-interference, high-integration and precise detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging seeker, in particular to an infrared, laser and millimeter wave three-mode composite detection seeker optical system. BACKGROUND

[0002] As the core component of precision guided weapons, the performance of the seeker determines the tracking, identification and capture ability of the guided weapon. The current mainstream guidance methods include infrared imaging guidance, laser guidance, radar guidance, etc.

[0003] The infrared guidance technology utilizes the strong infrared radiation of the target itself to realize automatic aiming, tracking and approaching of the missile to the target until hitting. Among various precision guidance technologies, infrared guidance occupies an important position in the development of modern weapon equipment due to its high guidance precision, strong anti-interference ability, good concealment and high efficiency-cost ratio.

[0004] Laser guidance transmits laser beams to irradiate the target through a laser radar. The reflected laser is received by a detector after being converged, and the frequency spectrum amplitude, phase and other information can be extracted. Combined with multi-sensor information fusion processing, the target can be accurately identified. Laser guidance also has the characteristics of high precision and strong anti-interference ability.

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

[0006] Multi-mode composite guidance technology is the research focus of countries around the world. The core of this technology is to realize optical-electric complementation: by taking advantage of the precise detection of different wavebands on the target and its local parts, the limitations of single waveband are overcome, and the advantages of each waveband are utilized to accurately transfer the target position to the back-end control system. This technology can improve the shortcomings of single-mode optical systems, realize performance complementation, and ultimately achieve all-weather operation and target precise positioning.

[0007] In the prior art, a Chinese patent with application number 202010936145.8 discloses an infrared, laser and millimeter wave common-caliber three-mode seeker optical system, which is composed of a head cover, a main mirror, a secondary mirror, a feed source, a waveguide, a millimeter wave transceiver module, an infrared channel, a laser channel and the like. The main defects of this system include: the millimeter wave feed source is located between the secondary mirror and the head cover, which has a large obstruction; a flat beam splitter is used for beam splitting, which is easy to introduce asymmetric astigmatism, has high installation difficulty, and the installation error has a significant impact on the imaging quality of the subsequent optical system; and the transmittance of the transmission eyepiece group in the infrared and laser wavebands is low. SUMMARY

[0008] The application provides an infrared, laser and millimeter wave three-mode composite detection seeker optical system, which improves light energy utilization and long-distance target detection capability, and realizes all-weather, anti-interference, long-distance and high-integration precise detection.

[0009] To achieve the above object, the application adopts the technical scheme of an infrared, laser and millimeter wave three-mode composite detection seeker optical system, which comprises, coaxially arranged along an optical axis from an object side to an image side, a fairing, a secondary mirror, a primary mirror, a millimeter wave phased array radar and a right-angle light splitting prism.

[0010] The millimeter wave phased array radar is located between the primary mirror and the right-angle light splitting prism, and a hole is arranged in the center of the millimeter wave phased array radar for the infrared and laser light to pass through, and the millimeter wave phased array radar is used for receiving external millimeter wave rays passing through the fairing, the secondary mirror and the primary mirror.

[0011] The right-angle light splitting prism is formed by splicing two triangular prisms into a cube through optical cementing, so that the infrared light is transmitted along the original direction and the laser light is reflected by 90 degrees.

[0012] The optical system further comprises an infrared imaging lens group arranged on a transmission light path of the right-angle light splitting prism, and a laser converging lens group arranged on a reflection light path of the right-angle light splitting prism.

[0013] The infrared imaging lens group comprises a first meniscus positive lens, a first meniscus negative lens and a second meniscus positive lens arranged in sequence along an optical path, and is used for imaging the infrared light on an infrared subsystem image plane.

[0014] The laser converging lens group comprises a plano-convex positive lens, a third meniscus positive lens and a fourth meniscus positive lens arranged in sequence along an optical path, and is used for focusing the laser light to a light-sensitive surface of a four-quadrant detector.

[0015] Further, the concave surface of the fairing is arranged to face the right-angle light splitting prism, 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 to face the right-angle light splitting prism, and the plane of the plano-convex positive lens is arranged to face the right-angle light splitting prism.

[0016] Further, the reflecting surface of the primary mirror is a parabolic surface, and the reflecting surface of the secondary mirror is a quadratic surface, and the quadratic surface coefficient k is 11.289.

[0017] Further, the obscuration ratio of the catadioptric system composed of the primary mirror and the secondary mirror is 0.5.

[0018] Further, the optical cementing method of the right-angle light splitting prism is that two polished triangular prism surfaces are bonded by molecular attraction through pressure without using any adhesive.

[0019] Further, the millimeter wave phased array radar adopts a microstrip patch array antenna in a flat panel form, and the diameter of the millimeter wave phased array radar is comparable to the diameter of the primary reflector.

[0020] Further, the material of the fairing is multi-spectrum zinc sulfide, the materials of the primary reflector and the secondary reflector are fused quartz, the material of the right-angle light splitting prism is zinc sulfide, the material of the first meniscus positive lens is monocrystalline germanium, the material of the first meniscus negative lens is zinc selenide, the material of the second meniscus positive lens is monocrystalline germanium, the materials of the plano-convex positive lens, the third meniscus positive lens and the fourth meniscus positive lens are H-ZLAF4LA.

[0021] Further, each lens satisfies the following conditions:

[0022] The 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;

[0023] The first meniscus negative lens: -0.6≤f7 / f≤-0.5, where f7 is the focal length of the first meniscus negative lens;

[0024] The second meniscus positive lens: 0.2≤f8 / f≤0.3, where f8 is the focal length of the second meniscus positive lens;

[0025] The plano-convex positive lens: 0.8≤f 10 / f≤0.9, where f 10 is the focal length of the plano-convex positive lens;

[0026] The third meniscus positive lens: 0.6≤f 11 / f≤0.7, where f 11 is the focal length of the third meniscus positive lens;

[0027] The fourth meniscus positive lens: 4.0≤f 12 / f≤4.2, where f 12 is the focal length of the fourth meniscus positive lens.

[0028] Further, the image-side surface of the first meniscus negative lens and the image-side surface of the second meniscus positive lens 8 are aspherical surfaces.

[0029] Further, the technical parameters of the infrared subsystem are: working waveband 8-12um, F#: 1.05, focal length: 70mm, field of view: 6.28*5.03°, wherein the F# calculation formula is f / D, f is the focal length of the optical system, and D is the diameter of the incident pupil; the technical parameters of the laser subsystem are: working waveband 1.064um, focal length 85mm, field of view 6°.

[0030] The beneficial effects of the present application are:

[0031] (1) The present application sets the millimeter wave phased array radar behind the primary mirror and before the right-angle light splitting prism, the diameter of the millimeter wave phased array radar is comparable to that of the primary mirror, the layout can effectively improve the array scale and realize long-distance detection; the central opening allows the infrared and laser beams to pass through without any obstruction, completely avoiding the shielding of the millimeter wave components to the infrared / laser light path, thereby improving the light energy utilization rate of the infrared and laser subsystems and ensuring that the weak radiation signals of the long-distance target can be effectively captured.

[0032] (2) The optical system of the present application effectively corrects various aberrations through reasonable distribution of the refractive power of each lens, matching of the optical materials of the lenses and optimized setting of the interval between each lens, the F number of the infrared system is optimized to 1.05, large relative aperture design is realized, the condensing capacity is greatly improved, and the light energy utilization rate is effectively improved, thereby realizing stable detection and identification of long-distance targets.

[0033] (3) The present application uses the right-angle light splitting prism to realize the light splitting of the infrared waveband and the laser waveband, and through the optical cementing method, the right-angle light splitting prism is fixed by molecular attraction without adhesive; the technical problem that the adhesive used in the traditional optical system for cementing the prism cannot transmit 8-12um long wave infrared is solved. The right-angle light splitting prism by the optical cementing method does not introduce aberration, the assembly and adjustment are simple, and the imaging clarity of the infrared subsystem to long-distance targets is ensured.

[0034] (4) The three-mode composite seeker optical system adopts common aperture design, which is beneficial to reducing the system size and reducing the platform scanning hardware, the three sensors are located on the same platform, the optical axis and the electrical axis coincide with each other, which is beneficial to maintaining the calibration of the sighting line, at the same time, the optical aperture area of the laser and the infrared and the aperture efficiency of the millimeter wave radar antenna are optimized.

[0035] (5) The millimeter wave phased array radar adopts a flat plate type microstrip patch array antenna, adopts a central opening to allow the infrared and laser light to pass through, and then adopts a light splitting mode behind the radar antenna to receive the laser and infrared signals respectively. The split laser and infrared systems are of the transmission type, and the design and adjustment difficulty is low; the flat array type antenna used in the millimeter wave system has good side lobe and clutter suppression performance. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1The optical path diagram of the optical system of the present application;

[0037] Figure 2 The transfer function diagram of the infrared subsystem of the present application;

[0038] Figure 3 The point diagram of the infrared subsystem of the present application;

[0039] Figure 4 The field curvature and distortion curve diagram of the infrared subsystem of the present application;

[0040] Figure 5 The spot diagram of the laser optical system after defocusing.

[0041] Wherein, 1 is a fairing, 2 is a main reflector, 3 is a secondary reflector, 4 is a millimeter wave phased array radar, 5 is a right-angle light splitting prism, 6 is a first meniscus positive lens, 7 is a first meniscus negative lens, 8 is a second meniscus positive lens, 9 is an infrared subsystem image plane, 10 is a plano-convex positive lens, 11 is a third meniscus positive lens, 12 is a fourth meniscus positive lens, and 13 is a four-quadrant detector receiving photosensitive surface. DETAILED DESCRIPTION

[0042] In order to make the above features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below in combination with the drawings. In the description of the present application, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right" and the like indicating the orientation or positional relationship, they are only relative to the drawings of the present application Figure 1 Corresponding, for the purpose of describing the present application, and not indicating or implying that the devices or elements referred to must have a particular orientation. The terms "first", "second", "third" are only for the purpose of description, referring to the order of the type of lens appearing, and cannot be understood as indicating or implying relative importance.

[0043] Throughout the description, the same reference numbers refer to the same elements. In the drawings, the drawings are only examples and are not strictly drawn to scale.

[0044] As common sense, the direction close to the object space is the object side, and the direction close to the image space is the image side. The direction from the object side to the image side, the two surfaces of the lens are in turn the incident surface and the exit surface. The object side refers to the light incident side, and the image side refers to the exit side. "Along the optical axis from the object side to the image side" means the direction from left to right in the figure. Figure 1 The surface of each lens facing the object side is called the object side surface, and the surface of each lens facing the image side is called the image side surface.

[0045] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0046] AsFigure 1 The infrared, laser, millimeter wave three-mode composite detection and guidance head optical system shown comprises, coaxially arranged along the optical axis from the object side to the image side: a fairing 1, a secondary mirror 3, a main mirror 2, a millimeter wave phased array radar 4, a right-angle light splitting prism 5, a first meniscus positive lens 6, a first meniscus negative lens 7, a second meniscus positive lens 8. The millimeter wave phased array radar 4 is located between the main mirror 2 and the right-angle light splitting prism 5, and the central aperture thereof allows the infrared and laser light rays to pass through, and the right-angle light splitting prism 5 is used to separate the infrared and laser light rays. After the infrared light path passes through the right-angle light splitting prism 5, it is imaged on the infrared subsystem image plane 9 in turn through the coaxially arranged first meniscus positive lens 6, first meniscus negative lens 7 and second meniscus positive lens 8. After the laser light path is reflected by the right-angle light splitting prism 5, the propagation direction forms a 90° angle with the incident direction, and then it is focused to the four-quadrant detector receiving photosensitive surface 13 in turn through the coaxially arranged plano-convex positive lens 10, third meniscus positive lens 11 and fourth meniscus positive lens 12.

[0047] In specific implementation, the fairing 1 adopts a spherical fairing, and the front surface and the rear surface of the fairing 1 are concentric spherical surfaces, and the thickness thereof is the difference between the radii of curvature of the front surface and the rear surface. The radius of curvature of the front surface is 100 mm, the radius of curvature of the rear surface is 95 mm, and the thickness is 5 mm. The concave surface of the fairing 1 is arranged to face the right-angle light splitting prism 5, and the convex surfaces of the first meniscus positive lens 6, first meniscus negative lens 7, second meniscus positive lens 8, third meniscus positive lens 11 and fourth meniscus positive lens 12 are arranged to face the right-angle light splitting prism 5, and the plane of the plano-convex positive lens 10 is arranged to face the right-angle light splitting prism 5.

[0048] The reflecting surface of the main mirror 2 is a parabolic surface, and the reflecting surface of the secondary mirror 3 is a quadratic surface, and the quadratic surface coefficient k = 11.289. The main mirror 2 is located between the secondary mirror 3 and the millimeter wave phased array radar 4, and the reflecting surface of the main mirror 2 faces the object side. The secondary mirror 3 is located between the fairing 1 and the main mirror 2, and the reflecting surface of the secondary mirror 3 faces the direction of the reflected light of the main mirror 2. After the infrared and laser light rays respectively transmit through the fairing 1, they are reflected by the main mirror 2 to the secondary mirror 3. The main mirror 2 has a central aperture, the diameter of the main mirror 2 is 85 mm, the diameter of the secondary mirror 3 is 42 mm, and the obscuration ratio of the catadioptric system composed of the main mirror 2 and the secondary mirror 3 is 0.5. After the millimeter wave rays pass through the fairing 1, they directly pass through the central region of the secondary mirror 3 and continue to propagate toward the main mirror 2, and are directly incident on the central aperture of the main mirror 2 along the system optical axis direction, and the central aperture of the main mirror 2 is directly opposite the receiving end of the millimeter wave phased array radar 4.

[0049] The right-angle light-splitting prism 5 is spliced into a cuboid by optical cementing of two triangular prisms, so that the infrared light transmits in the original direction, and the laser light reflects in a direction 90° to the incident direction, i.e. the exit direction is 90° to the incident direction. Specifically, the right-angle light-splitting prism 5 is spliced by optical cementing of two clean, smooth and identical triangular prisms by pressure, and is spliced by the molecular attraction between the two polished triangular prism surfaces without using any adhesive.

[0050] Preferably, the millimeter wave phased array radar 4 antenna part adopts a flat plate form, which is a microstrip patch array antenna. The millimeter wave phased array radar 4 adopts a central opening to allow the infrared and laser light to pass through. Moreover, the diameter of the millimeter wave phased array radar 4 is comparable to the diameter of the primary mirror 2, and the central opening diameter of the millimeter wave phased array radar 4 is comparable to the central opening diameter of the primary mirror 2.

[0051] In this embodiment, the material of the fairing 1 is multi-spectrum zinc sulfide CVD ZNS, the material of the primary mirror 2 is fused silica SILICA, the material of the secondary mirror 3 is fused silica SILICA, the material of the right-angle light-splitting prism 5 is zinc sulfide ZNS, the material of the first meniscus positive lens 6 is monocrystalline germanium Ge, the material of the first meniscus negative lens 7 is zinc selenide ZNSE, the material of the second meniscus positive lens 8 is monocrystalline germanium Ge, the material of the plano-convex positive lens 10 is H-ZLAF4LA, the material of the third meniscus positive lens 11 is H-ZLAF4LA, and the material of the fourth meniscus positive lens 12 is H-ZLAF4LA.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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, and f 10 is the focal length of the plano-convex positive lens.

[0056] 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, and f11 focal length of the third meniscus positive lens;

[0057] The fourth meniscus positive lens 12 satisfies the following condition: 4.0≤f 12 f / f≤4.2, wherein f is the focal length of the optical system, f 12 focal length of the fourth meniscus positive lens.

[0058] The light transmission path of the infrared subsystem of the optical system is as follows: the infrared light of 8-12 μm wavelength emitted by the external scene infrared radiation passes through the spherical dome 1, reaches the primary mirror 2, is reflected by the primary mirror 2, reaches the secondary mirror 3, is reflected by the secondary mirror 3, passes through the central hole of the millimeter wave phased array radar 4, reaches the right-angle light-splitting prism 5, passes through the right-angle light-splitting prism 5, reaches the first meniscus positive lens 6, is converged by the first meniscus positive lens 6, reaches the first meniscus negative lens 7, is diverged by the first meniscus negative lens 7, reaches the second meniscus positive lens 8, is converged by the second meniscus positive lens 8, and is imaged on the infrared subsystem image plane 9.

[0059] The light transmission path of the laser subsystem of the optical system is as follows: the laser light of 1.064 μm wavelength reflected by the external scene passes through the spherical dome 1, reaches the primary mirror 2, is reflected by the primary mirror 2, reaches the secondary mirror 3, is reflected by the secondary mirror 3, passes through the central hole of the millimeter wave phased array radar 4, reaches the right-angle light-splitting prism 5, is reflected by the right-angle light-splitting prism 5, reaches the plano-convex positive lens 10, is converged by the plano-convex positive lens 10, reaches the third meniscus positive lens 11, is converged by the third meniscus positive lens 11, reaches the fourth meniscus positive lens 12, is converged by the fourth meniscus positive lens 12, and reaches the four-quadrant detector receiving photosensitive surface 13.

[0060] The light transmission path of the radar subsystem of the optical system is as follows: the millimeter wave light reflected by the external scene passes through the spherical dome 1, the secondary mirror 3, and the primary mirror 2, and reaches the millimeter wave phased array radar 4.

[0061] Table 1 is the technical index realized by the infrared subsystem of the present application, wherein the optical system F number calculation formula is f / D, f is the focal length of the optical system, and D is the diameter of the incident pupil.

[0062] Table 1 is the technical index realized by the infrared subsystem of the present application.

[0063]

[0064] Table 2 is the technical index realized by the laser subsystem of the present application.

[0065] Table 2 is the technical index realized by the laser subsystem of the present application.

[0066]

[0067] Table 3 and Table 4 list detailed data of optical system embodiments of the present application, which include the surface shape, the radius of curvature, the thickness, and the material of each lens. In the table, the radius of curvature and the thickness of the lens are in mm, and the radius of curvature of the spherical surface and the aspherical surface refers to the radius of curvature at the intersection of the lens surface and the optical axis. In Table 3 and Table 4, "radius" represents the radius of curvature of the surface, and the positive and negative determination principle is that the intersection of the surface and the principal axis is taken as the starting point, and the center of the surface curvature is taken as the end point. If the direction of the connecting line is the same as the direction of the light propagation, it is positive, otherwise it is negative. If the surface is a plane, the radius of curvature of the surface is infinite; "thickness" in Table 3 and Table 4 gives the distance of the adjacent two surfaces on the optical axis, and the positive and negative determination principle is that the vertex of the current surface is taken as the starting point, and the vertex of the next surface is taken as the end point. If the direction of the connecting line is the same as the direction of the 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, and if there is no material between the two surfaces, it represents the air gap between the two lenses.

[0068] Table 3 Detailed data of infrared subsystem in the embodiment of the present application

[0069]

[0070] Table 4 Detailed data of laser subsystem in the embodiment of the present application

[0071]

[0072] The infrared, laser, and millimeter wave three-mode composite detection and guidance head optical system, the surface of the first meniscus negative lens 7 towards the image side, i.e. the exit surface, and the surface of the second meniscus positive lens 8 towards the image side, i.e. the exit surface, are aspherical surfaces.

[0073] Further, the surface shape equation of each aspherical surface is as follows:

[0074]

[0075] Wherein, z is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of r along the optical axis direction, 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 direction, k is the quadratic curve constant, A is the fourth-order aspherical surface coefficient, B is the sixth-order aspherical surface coefficient, C is the eighth-order aspherical surface coefficient, and D is the tenth-order aspherical surface coefficient.

[0076] Table 5 lists the aspherical surface coefficients of the surface of the first meniscus negative lens 7 towards the image side, i.e. the exit surface, and the surface of the second meniscus positive lens 8 towards the image side, i.e. the exit surface, according to the present application. In the table, scientific notation is used, for example, 4.63665e-007 represents 4.63665 x 10 -7.

[0077] Table 5 Aspherical coefficients of the optical system in the embodiments of the present invention

[0078]

[0079] After simulation using optical design software, such as Figure 2 As 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.

[0080] 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 infrared, laser, millimeter wave three-mode composite seeker optical system, characterized in that, The optical system comprises, in sequence along the optical axis from the object side to the image side, a fairing (1), a secondary mirror (3), a primary mirror (2), a millimeter wave phased array radar (4), and a right-angle light splitting prism (5); the reflecting surface of the primary mirror (2) faces the object side, and the center thereof is provided with an opening; the reflecting surface of the secondary mirror (3) faces the direction of reflected light of the primary mirror (2); The millimeter wave phased array radar (4) is located between the primary mirror (2) and the right-angle light splitting prism (5), and the center thereof is provided with an opening for passing infrared and laser light, and is used for receiving external millimeter wave rays passing through the fairing (1), the secondary mirror (3) and the primary mirror (2); The right-angle light splitting prism (5) is formed by splicing two triangular prisms into a cube through optical cementing, so that the infrared light is transmitted along the original direction, and the laser light is reflected by 90 degrees; The optical system further comprises an infrared imaging lens group arranged on the transmission light path of the right-angle light splitting prism (5), and a laser converging lens group arranged on the reflection light path of the right-angle light splitting prism (5); The infrared imaging lens group comprises, in sequence along the optical path, a first meniscus positive lens (6), a first meniscus negative lens (7) and a second meniscus positive lens (8), and is used for imaging the infrared light on an infrared subsystem image plane (9); The laser converging lens group comprises, in sequence along the optical path, a plano-convex positive lens (10), a third meniscus positive lens (11) and a fourth meniscus positive lens (12), and is used for focusing the laser light to a four-quadrant detector receiving photosensitive surface (13).

2. The optical system of the infrared, laser and millimeter wave three-mode combined seeker according to claim 1, characterized in that, The concave surface of the fairing (1) faces the right-angle light splitting 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 light splitting prism (5), and the plane of the plano-convex positive lens (10) faces the right-angle light splitting prism (5).

3. The optical system of the infrared, laser and millimeter wave three-mode combined homing head according to claim 1, characterized in that, The reflecting surface of the primary mirror (2) is a parabolic surface, and the reflecting surface of the secondary mirror (3) is a quadratic surface, and the quadratic surface coefficient k=11.

289.

4. The optical system of the infrared, laser and millimeter wave three-mode combined homing head according to claim 1 or 3, characterized in that, The obscuration ratio of the catadioptric system composed of the primary mirror (2) and the secondary mirror (3) is 0.

5.

5. The optical system of an infrared, laser, millimeter wave three-mode composite seeker according to claim 1, characterized in that, The optical cementing method of the right-angle light splitting prism (5) is that two polished triangular prism surfaces are bonded by molecular attraction through pressure without using any adhesive.

6. The optical system of an infrared, laser, millimeter wave three-mode composite seeker 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 plate, and the diameter of the millimeter wave phased array radar (4) is comparable to the diameter of the primary mirror (2).

7. The optical system of an infrared, laser, millimeter wave three-mode composite seeker according to claim 1, characterized in that, The material of the fairing (1) is multi-spectrum zinc sulfide, the materials of the primary mirror (2) and the secondary mirror (3) are fused quartz, the material of the right-angle light splitting prism (5) is zinc sulfide, the material of the first meniscus positive lens (6) is monocrystalline germanium, the material of the first meniscus negative lens (7) is zinc selenide, the material of the second meniscus positive lens (8) is monocrystalline germanium, the materials of the plano-convex positive lens (10), the third meniscus positive lens (11) and the fourth meniscus positive lens (12) are all H-ZLAF4LA.

8. The optical system of an infrared, laser, millimeter wave three-mode composite seeker according to claim 1, characterized in that, Each lens satisfies the following conditions: The first meniscus positive lens (6) satisfies 0.7≤f6 / f≤0.8, wherein 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 -0.6≤f7 / f≤-0.5, wherein f7 is the focal length of the first meniscus negative lens; The second meniscus positive lens (8) satisfies 0.2≤f8 / f≤0.3, wherein 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 is the focal length of the plano-convex positive lens; third meniscus positive lens (11): 0.6 ≤ f 11 / f ≤ 0.7, where f 11 is the focal length of the third meniscus positive lens; Fourth meniscus positive lens (12): 4.0 < f 12 / f < 4.2, where f 12 is the focal length of the fourth meniscus positive lens.

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

10. The optical system of an infrared, laser, millimeter wave three-mode composite seeker according to claim 1, characterized in that, The technical parameters of the infrared subsystem are: working waveband 8μm-12μm, F#: 1.05, focal length: 70 mm, field of view: 6.28° x 5.03°, wherein, The F# calculation formula is f / D, wherein f is the focal length of the optical system, and D is the diameter of the incident pupil; the technical parameters of the laser subsystem are: working waveband 1.064μm, focal length 85mm, and field of view 6°.

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