Low-cost long-wave refrigeration athermalization optical system based on chalcogenide material
By designing a low-cost, long-wavelength cooled, athermalized optical system based on chalcogenide materials, and employing a three-piece structure using chalcogenide glass IRG206 and germanium materials, high-resolution imaging over a wide temperature range was achieved. This solves the problem of athermalized design in existing technologies and improves the system's environmental adaptability and imaging quality.
Patent Information
- Application Number
- CN202520097983.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2035-01-16
AI Technical Summary
Existing technologies struggle to achieve a calorimetric design for low-cost, high-resolution long-wave infrared imaging detection systems over a wide temperature range, and existing systems suffer from deficiencies in environmental adaptability and imaging quality.
A low-cost, long-wavelength cooled, athermalized optical system based on chalcogenide materials was designed, featuring a three-element structure for single-imaging. Chalcogenide glass IRG206 and germanium were used as lens materials, and a wide-temperature athermalized design was achieved through a binary surface. The optical aberration and thermal aberration were balanced by combining advanced aberration theory, and a Stirling-cooled area array detector was selected to achieve high-resolution imaging.
Within a temperature range of -40℃ to +70℃, it achieves high-resolution, low-distortion, and low-cost imaging effects. The system has a simple and lightweight structure, making it suitable for fields such as aerospace optical remote sensing, optical imaging guidance, astronomical observation, and civilian security surveillance.
Smart Images
Figure CN223637809U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to optical imaging technical field, especially, relate to a kind of low-cost long-wave refrigeration athermalization optical system based on chalcogenide material. BACKGROUND
[0002] With the high-speed development of infrared detector, infrared imaging detection technology plays an increasingly important role in science and technology, national economy, national defense and military fields. The utility model is based on a high-resolution small-pixel long-wave infrared refrigeration detector with a response band of 7.7 μm to 10.3 μm, a resolution of 640x512, and a pixel size of 15 μm. A low-cost long-wave refrigeration athermalization optical system based on chalcogenide material is designed. This system has excellent imaging quality, strong light collection ability, good environmental adaptability, strong anti-interference ability, and can work all day long in the temperature range of -40°C to +70°C. It can be widely used in aerospace optical remote sensing, optical imaging guidance, astronomical observation, civil safety monitoring and other fields, and has broad application prospects and huge economic benefits.
[0003] In summary, a low-cost long-wave refrigeration athermalization optical system based on chalcogenide material is proposed. SUMMARY
[0004] Therefore, the utility model aims to realize low-cost, athermalization, and high-resolution design of long-wave refrigeration infrared imaging detection system. The utility model provides a low-cost long-wave refrigeration athermalization optical system based on chalcogenide material.
[0005] To achieve the above purpose, the utility model adopts the following technical scheme to provide a low-cost long-wave refrigeration athermalization optical system based on chalcogenide material, which comprises:
[0006] A low-cost long-wave refrigeration athermalization optical system based on chalcogenide material is arranged from outside to inside in the propagation direction of light. The optical system comprises a fairing, a first lens, a second lens, a third lens, a detector protection glass, a cold light diaphragm, and an image plane. The first lens, the second lens, the third lens, the detector protection glass, the cold light diaphragm, the image plane, and the fairing are coaxially arranged. The optical system is used to receive infrared radiation inherent to targets and backgrounds, and to converge the radiation onto the photosensitive surface of a long-wave infrared refrigeration detector. Through photoelectric conversion, the optical signal is converted into an electrical signal.
[0007] Furthermore, the first lens and the third lens are both spherical lenses. The outer surface of the second lens is a binary surface, and the inner surface is a spherical surface.
[0008] Furthermore, the radius of curvature of the outer surface of the fairing is 115 mm, the radius of curvature of the inner surface is 110 mm, and the thickness is 5 mm; the radius of curvature of the outer surface of the first lens is 50.6 mm, the radius of curvature of the inner surface is 135.19 mm, and the thickness is 8.3 mm; the radius of curvature of the outer surface of the second lens is 174.25 mm, the radius of curvature of the inner surface is 68.05 mm, and the thickness is 4.2 mm; the radius of curvature of the outer surface of the third lens is 77.22 mm, the radius of curvature of the inner surface is 199.99 mm, and the thickness is 4 mm; the diffraction parameters of the outer surface of the second lens are quadratic surface constants K = 0, C = 1 / 135.19, and the coefficients for the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth orders are a2 = 0, a4 = -3.224 × 10⁻⁴, and a₄ = -3.224 × 10⁻⁴, respectively. －7 a6 = -1.917 × 10 －10 a8 = -8.486 × 10 －14 a 10 =2.867×10 －15 a 12 =8.520×10 －19 a 14 =9.635×10 －21 The diffraction order is 1, the diffraction ring number is 8, and C1 = -1.56305 × 10⁻⁶. －5 .
[0009] Furthermore, the fairing is a concentric convex lens made of zinc sulfide; the first lens and the third lens are meniscus convex lenses, the first lens being made of chalcogenide glass IRG206 and the third lens being made of germanium; the second lens is a meniscus concave lens made of germanium.
[0010] Furthermore, the distance between the fairing and the first lens is 5 mm; the distance between the first lens and the second lens is 1.5 mm; the distance between the second lens and the third lens is 34.6 mm; the distance between the third lens and the detector protective glass is 11.45 mm; the distance between the detector protective glass and the cold aperture is 2.86 mm; and the distance between the cold aperture and the image plane is 20.47 mm.
[0011] Furthermore, the optical system operates in the wavelength range of 7.7μm to 10.3μm, has a focal length of 50mm, an F-number of 2, a field of view of 10.9° × 8.7°, and at 33lp / mm, has a modulation transfer function value of ≥0.28 for the 0 field of view, a transfer function value of ≥0.24 for the other fields of view, and a system distortion of ≤1%.
[0012] Further, the optical system is designed in a one-time imaging 3-piece structure, uses chalcogenide glass IRG206 and germanium as lens materials, and realizes wide-temperature athermalization design of the optical system by using only one binary surface, and the maximum value of distortion of the optical system is -0.96% in a temperature range of -40 DEG C to +70 DEG C; the transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm at -40 DEG C, and the transfer function values of other fields are greater than or equal to 0.22; the transfer function value of 0 field is greater than or equal to 0.28 at 33 lp / mm at 20 DEG C, and the transfer function of other fields is greater than or equal to 0.24; the transfer function of 0 field is greater than or equal to 0.27 at 33 lp / mm at +70 DEG C, and the transfer function of other fields is greater than or equal to 0.23.
[0013] Further, the optical system has an outer size of < φ50mm*63mm and a total weight of < 150g.
[0014] Beneficial effects:
[0015] 1. The working waveband of the optical system is 7.7-10.3 microns, the focal length is 50mm, the F number is 2, the full field distortion is less than or equal to 1%, the field of view is 10.9*8.7 degrees, the detector selects a Stirling refrigeration detector with a resolution of 640*512 and a pixel size of 15 microns, and the optical system is a small F number long wave refrigeration infrared optical system, and has the characteristics of large relative aperture, high resolution and strong light collection capacity.
[0016] 2. The optical system adopts a one-time imaging 3-piece optical structure of IRG206-GE-GE, has an outer size of < φ50mm*63mm and a total weight of < 150g, and has the characteristics of simple structure, small volume, light weight and easy installation.
[0017] 3. The detector of the optical system selects an optical system with a transfer function of 0 field being greater than or equal to 0.28 and other fields being greater than or equal to 0.24 at 33 lp / mm, and has excellent imaging quality and a single pixel angle of less than 0.3 mrad.
[0018] 4. The optical system selects two most commonly used, stable and mature optical materials of chalcogenide glass IRG206 and germanium as lens materials, effectively balances the contradiction between optical aberration and thermal aberration by using advanced aberration theory, realizes wide-temperature athermalization design of the optical system by using only one binary surface, has excellent imaging quality in a range of -40 DEG C to +70 DEG C, has few lenses, high transmittance, strong environmental adaptability, low cost and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS
[0019] The accompanying drawings, which form a part of this patent, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:
[0020] Figure 1 The overall structure schematic diagram of A is described in the application;
[0021] Figure 2 The modulation transfer function curve when +70 DEG C;
[0022] Figure 3 The modulation transfer function curve when +20 DEG C;
[0023] Figure 4 The modulation transfer function curve when -40 DEG C;
[0024] Figure 5 The optical system distortion and field curve.
[0025] In the drawing: the fairing 1; the first lens 2; the second lens 3; the third lens 4; the detector protection glass 5; the cold light diaphragm 6; the image plane 7. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the application will be clearly and completely described with reference to the drawings in the embodiments of the application. It should be explained that, in the case of no conflict, the embodiments in the application and the features in the embodiments can be combined with each other, and the described embodiments are only part of the embodiments of the application, rather than all the embodiments.
[0027] It should be explained that the description of the application about "left", "right", "left side", "right side", "upper part", "lower part", "top", "bottom" and the like is defined based on the position or relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and is not intended to indicate or imply that the structure must be constructed and operated in a particular position, therefore, it cannot be understood as a limitation on the application. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.
[0028] In the description of the application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.
[0029] Referring to the accompanying drawings, this embodiment provides a low-cost, long-wavelength cooled, athermalized optical system based on chalcogenide materials. A radome 1, a first lens 2, a second lens 3, a third lens 4, a detector protective glass 5, a cold aperture 6, and an image plane 7 are sequentially arranged along the light propagation direction. The first lens 2, second lens 3, third lens 4, detector protective glass 5, cold aperture 6, and image plane 7 are coaxially arranged with the radome 1. The optical system receives the inherent infrared radiation from the target and background and converges it onto the photosensitive surface of a long-wavelength infrared cooled detector. Through photoelectric conversion, the optical signal is converted into an electrical signal. The system has high sensitivity and low spatial resolution, enabling target detection, identification, and precise positioning at night or under complex weather conditions.
[0030] The specific objective of this technical solution is to achieve a low-cost, athermal design for a cooled infrared seeker. Based on chalcogenide glass IRG206 and germanium optical materials, and utilizing a three-element optical structure IRG206-Ge-Ge for single-image imaging, a Stirling-cooled long-wave infrared detector with a 640×512 pixel area and a 15μm size is selected as the receiving device. This design creates an athermal, high-resolution, and low-cost long-wave cooled infrared imaging detection optical system capable of detecting, identifying, and precisely locating targets.
[0031] In this embodiment, both the first lens 2 and the third lens 4 are spherical lenses; the outer surface of the second lens 3 is a binary surface, and the inner surface is a sphere. The binary surface includes an aspherical surface and a diffractive surface;
[0032] The equation of an aspherical surface is
[0033]
[0034] In the formula: H is the sum of the squares of the horizontal and vertical coordinates, H 2 =X 2 +Y 2 K is the constant of the quadratic surface; C is the curvature, a2, a4, a6, a8, a 10 a 12 It is the aspherical coefficient.
[0035] The equation of the diffraction surface is:
[0036]
[0037] In the formula: H is the sum of the squares of the horizontal and vertical coordinates, H 2 =X 2 +Y 2 m is the diffraction zone number; n0 is the material refractive index; C1 is the secondary phase coefficient.
[0038] In the embodiment, the outer surface of the fairing 1 has a curvature radius of 115 mm, the inner surface has a curvature radius of 110 mm, and the thickness is 5 mm; the outer surface of the first lens 2 has a curvature radius of 50.6 mm, the inner surface has a curvature radius of 135.19 mm, and the thickness is 8.3 mm; the outer surface of the second lens 3 has a curvature radius of 174.25 mm, the inner surface has a curvature radius of 68.05 mm, and the thickness is 4.2 mm; the outer surface of the third lens 4 has a curvature radius of 77.22 mm, the inner surface has a curvature radius of 199.99 mm, and the thickness is 4 mm; the outer surface of the second lens 3 has a diffractive surface parameter of quadratic surface constant K=0, C=1 / 135.19, second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, and fourteenth-order coefficients are a2=0, a4=-3.224×10-4, a6=-1.917×10-5, a8=-8.486×10-6, a10=2.867×10-6, a12=8.520×10-7, a14=9.635×10-8, the diffraction order is 1, the number of diffraction rings is 8, and C1=-1.56305×10-4. －7 －10 －14 10 －15 12 －19 14 －21 －5 .
[0039] In the embodiment, the fairing 1 is a concentric convex lens, and the material is zinc sulfide; the first lens 2 and the third lens 4 are meniscus convex lenses, the material of the first lens 2 is IRG206 sulfide glass, and the material of the third lens 4 is germanium; the second lens 3 is a meniscus concave lens, and the material is germanium.
[0040] In the embodiment, the distance between the fairing 1 and the first lens 2 is 5 mm; the distance between the first lens 2 and the second lens 3 is 1.5 mm; the distance between the second lens 3 and the third lens 4 is 34.6 mm; the distance between the third lens 4 and the detector protection glass 5 is 11.45 mm; the distance between the detector protection glass 5 and the cold light stop 6 is 2.86 mm; and the distance between the cold light stop 6 and the image plane 7 is 20.47 mm.
[0041] The first lens and the third lens are spherical lenses; the outer surface of the second lens is a binary surface, and the inner surface is a spherical surface.
[0042] The technical scheme limits the material, quantity and face shape of each lens. In the design, a one-time imaging 3-piece IRG206-Ge-Ge structure is adopted, the senior aberration theory is used, the thermal expansion coefficients of optical and mechanical materials are considered, the contradiction between optical aberration and thermal difference is effectively balanced, sulfide glass and germanium, two most commonly used optical materials with good stability and mature processing technology, are selected as lens materials, and aluminum is selected as the lens barrel material. Only one binary diffraction surface is used to realize the wide-temperature non-thermal design of the optical system, the imaging quality is excellent in the range of-40 DEG C to +70 DEG C, the structure is simple, the lens quantity is small, the transmittance is high, the single-pixel angle is 0.3 mrad, the detection distance is far, the environmental adaptability is strong, the lens is easy to assemble and calibrate, the cost is low, and the lens is suitable for mass production.
[0043] In the embodiment, the working waveband of the optical system is 7.7 μm to 10.3 μm, the focal length is 50 mm, the F number is 2, the field of view size is 10.9°*8.7°, the modulation transfer function value of the 0 field of view is greater than or equal to 0.28 at 33 lp / mm, the modulation transfer function values of the rest of the fields of view are greater than or equal to 0.24, and the system distortion is less than or equal to 1%.
[0044] The working waveband of the optical system is 7.7 μm to 10.3 μm, the focal length is 50 mm, the F number is 2, the full field of view distortion is less than or equal to 1%, the field of view is 10.9°*8.7°, the detector is selected to be a Stirling refrigeration detector with a resolution of 640*512 and a pixel size of 15 μm, the optical system is a small-F-number long-wave refrigeration infrared optical system, and has the characteristics of a large relative aperture, high resolution and strong light collection capability.
[0045] The technical scheme limits the technical parameters of the working waveband, focal length, F number, field of view size, detector resolution and pixel size of the optical system, and has the characteristics of high resolution, large relative aperture and strong light collection capability.
[0046] In the embodiment, the optical system is designed in a one-time imaging 3-piece structure, sulfide glass IRG206 and germanium are selected as lens materials, and only one binary surface is used to realize the wide-temperature non-thermal design of the optical system. In the temperature range of-40 DEG C to +70 DEG C, the maximum value of the distortion of the optical system is-0.96%; at-40 DEG C, the transfer function value of the 0 field of view is greater than or equal to 0.27 at 33 lp / mm, the transfer function values of the rest of the fields of view are greater than or equal to 0.22; at 20 DEG C, the transfer function value of the 0 field of view is greater than or equal to 0.28 at 33 lp / mm, the transfer function values of the rest of the fields of view are greater than or equal to 0.24; and at +70 DEG C, the transfer function value of the 0 field of view is greater than or equal to 0.27 at 33 lp / mm, the transfer function values of the rest of the fields of view are greater than or equal to 0.23.
[0047] The optical system has a distortion design maximum value of -0.96% in a temperature range of -40 DEG C to +70 DEG C; a transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.22; at 20 DEG C, a transfer function value of 0 field is greater than or equal to 0.28 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.24; at +70 DEG C, a transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.23.
[0048] The optical system has a distortion design maximum value of -0.96% in a temperature range of -40 DEG C to +70 DEG C; a transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.22; at 20 DEG C, a transfer function value of 0 field is greater than or equal to 0.28 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.24; at +70 DEG C, a transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and transfer function values of other fields are greater than or equal to 0.23.
[0049] In the embodiment, the optical system has an outer size of <φ50mm*63mm and an optical total weight of <150g.
[0050] The optical system has an outer size of <φ50mm*63mm and an optical total weight of <150g.
[0051] Working principle of the infrared imaging guidance system:
[0052] The infrared imaging guidance system is composed of a fairing, an optical system and a long-wave refrigeration detector. The fairing is an optical detection window, has high transmittance in the working waveband of the system, forms a sealed space with other parts of the guidance head, and is used for protecting the internal devices of the guidance head to make the internal devices work normally under thermal impact. The optical system is used for receiving the infrared radiation inherent to the target and the background, converging the infrared radiation to the photosensitive surface of the long-wave infrared refrigeration detector, converting the optical signal into an electrical signal through photoelectric conversion, and realizing the detection, identification and accurate positioning of the target at night or under complex weather conditions.
[0053] The above disclosed embodiments of the utility model are only used for helping to set forth the utility model. The embodiments do not describe all the details, and also do not limit the utility model to the specific implementation mode. According to the content of the specification, many modifications and changes can be made. The specification selects and specifically describes these embodiments, in order to better explain the principle and practical application of the utility model, so that the person skilled in the art can well understand and utilize the utility model.
Claims
1. A low-cost long-wave refrigeration athermalized optical system based on chalcogenide materials, characterized in that: The fairing (1), the first lens (2), the second lens (3), the third lens (4), the detector protection glass (5), the cold light diaphragm (6) and the image plane (7) are coaxially arranged with the fairing (1); the optical system is used for receiving infrared radiation inherent to the target and the background, converging to the long-wave infrared refrigeration detector photosensitive surface, converting the optical signal into the electrical signal through photoelectric conversion.
2. The low-cost long-wave chiller athermalized optical system based on chalcogenide material according to claim 1, characterized in that: The first lens (2) and the third lens (4) are spherical lenses; the outer surface of the second lens (3) is a binary surface, and the inner surface is a spherical surface.
3. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The curvature radius of the outer surface of the fairing (1) is 115 mm, the curvature radius of the inner surface is 110 mm, and the thickness is 5 mm; the curvature radius of the outer surface of the first lens (2) is 50.6 mm, the curvature radius of the inner surface is 135.19 mm, and the thickness is 8.3 mm; the curvature radius of the outer surface of the second lens (3) is 174.25 mm, the curvature radius of the inner surface is 68.05 mm, and the thickness is 4.2 mm; the curvature radius of the outer surface of the third lens (4) is 77.22 mm, the curvature radius of the inner surface is 199.99 mm, and the thickness is 4 mm; the diffraction surface parameter of the outer surface of the second lens (3) is quadratic surface constant K=0, C=1 / 135.19, and the second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order and fourteenth-order coefficients are a2=0, a4=-3.224×10-7, a6=-1.917×10-10, a8=-8.486×10-14, a10=2.867×10-15, a12=8.520×10-19, a14=9.635×10-21 respectively, the diffraction order is 1, the diffraction ring number is 8, and C1=-1.56305×10-5.
4. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The fairing (1) is a concentric circle convex lens, and the material is zinc sulfide; the first lens (2) and the third lens (4) are meniscus convex lenses, the material of the first lens (2) is sulfur glass IRG206, and the material of the third lens (4) is germanium; the second lens (3) is a meniscus concave lens, and the material is germanium.
5. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The distance between the fairing (1) and the first lens (2) is 5 mm; the distance between the first lens (2) and the second lens (3) is 1.5 mm; the distance between the second lens (3) and the third lens (4) is 34.6 mm; the distance between the third lens (4) and the detector protection glass (5) is 11.45 mm; the distance between the detector protection glass (5) and the cold light diaphragm (6) is 2.86 mm; and the distance between the cold light diaphragm (6) and the image plane (7) is 20.47 mm.
6. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The working waveband of the optical system is 7.7-10.3 microns, the focal length is 50 mm, the F number is 2, the field of view size is 10.9*8.7 degrees, the modulation transfer function value of 0 field is greater than or equal to 0.28 at 33 lp / mm, the modulation transfer function value of other fields is greater than or equal to 0.24, and the system distortion is less than or equal to 1%.
7. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The optical system is designed in a one-time imaging three-piece structure, uses chalcogenide glass IRG206 and germanium as lens materials, and realizes wide-temperature athermalization design by using only one binary surface; within a temperature range of-40-+70 DEG C, the maximum value of the optical system distortion design is-0.96%; at-40 DEG C, the modulation transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and the modulation transfer function value of other fields is greater than or equal to 0.22; at 20 DEG C, the modulation transfer function value of 0 field is greater than or equal to 0.28 at 33 lp / mm, and the modulation transfer function value of other fields is greater than or equal to 0.24; at +70 DEG C, the modulation transfer function value of 0 field is greater than or equal to 0.27 at 33 lp / mm, and the modulation transfer function value of other fields is greater than or equal to 0.
23.
8. The low-cost long-wave chiller athermalized optical system based on chalcogenide material of claim 1, wherein: The size of the optical system is less than or equal to 50 mm*63 mm, and the total weight of the optical system is less than or equal to 150 g.