CN118151355A - Ultra-low self heat radiation long wave infrared optical system - Google Patents
Ultra-low self heat radiation long wave infrared optical system Download PDFInfo
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- 230000003287 optical effect Effects 0.000 title claims abstract description 60
- 230000005855 radiation Effects 0.000 title claims abstract description 47
- 239000005357 flat glass Substances 0.000 claims abstract description 21
- 210000001747 pupil Anatomy 0.000 claims abstract description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 claims description 9
- 210000000887 face Anatomy 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 238000002310 reflectometry Methods 0.000 claims description 7
- 230000000903 blocking effect Effects 0.000 claims description 6
- 239000003973 paint Substances 0.000 claims description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 5
- 239000010931 gold Substances 0.000 claims description 5
- 229910052737 gold Inorganic materials 0.000 claims description 5
- 230000000007 visual effect Effects 0.000 claims description 5
- 238000010521 absorption reaction Methods 0.000 claims description 3
- 230000008033 biological extinction Effects 0.000 claims description 3
- 229910052732 germanium Inorganic materials 0.000 claims description 3
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 21
- 238000003384 imaging method Methods 0.000 abstract description 4
- 230000004907 flux Effects 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000005457 Black-body radiation Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000003331 infrared imaging Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B17/00—Systems with reflecting surfaces, with or without refracting elements
- G02B17/02—Catoptric systems, e.g. image erecting and reversing system
- G02B17/06—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror
- G02B17/0647—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror using more than three curved mirrors
- G02B17/0663—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror using more than three curved mirrors off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/14—Protective coatings, e.g. hard coatings
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
- G02B5/0808—Mirrors having a single reflecting layer
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
- G02B5/10—Mirrors with curved faces
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- Optics & Photonics (AREA)
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Abstract
An ultra-low self heat radiation long wave infrared optical system belongs to the technical field of infrared optics and solves the technical problems of low signal-to-noise ratio, poor image contrast and short system detection distance of a space-based infrared optical detection system. The system comprises the following components in sequence from the light propagation direction: an aperture diaphragm, a primary mirror, a secondary mirror, a field diaphragm, three mirrors, four mirrors, window glass and an image plane; the main mirror, the secondary mirror, the three mirrors and the four mirrors form an off-axis four-return optical lens group; after passing through the aperture diaphragm, the incident light is reflected by the off-axis four-return optical lens group, imaged through window glass, and received the radiation energy of the long-wave infrared optical system at the image surface; the field stop is located between the secondary mirror and the tertiary mirror. The system is an off-axis system, which is more conducive to the collection of infrared radiant energy relative to an off-axis system. The imaging quality is excellent, and under the conditions that the system parameters are the entrance pupil diameter of 280mm, the field angle of view of 1.2 degrees and the focal length of 840mm, the distortion is smaller than 0.1%, and the root mean square diameter of the point list is smaller than 25um.
Description
Technical Field
The invention belongs to the technical field of infrared optics, and relates to an ultra-low self heat radiation long-wave infrared optical system.
Background
Compared with a visible light detection system, the infrared optical detection system has the advantages of acquiring the radiation characteristics of an infrared target, acquiring the geometric or material information of the target through detection, and having passive concealment, wherein the visible light target acquires the reflected light information of the target by utilizing the reflection of the surface of the visible light target to natural light, so that the object which is easy to monitor is found, and the concealment is poor. Secondly, when a target monitored by visible light is in a back shadow area irradiated by the sun, the visible light detection cannot be continuously monitored; the infrared detection can continue tracking and monitoring so as to avoid losing the target, and all-weather monitoring can be realized.
With the development of the detector, such as the improvement of integration time and the reduction of dark current, the factors limiting the high sensitivity of the infrared detection system are mainly background thermal radiation and an optical system, especially in a long-wave band range, and the outward radiation quantity of the optical system (optical element, lens barrel, supporting rib, etc.) reaches a detection surface and is often several orders of magnitude larger than the radiation quantity of a weak signal target, which is not neglected. However, with the development of space detection technology, the infrared imaging system is widely applied in the fields of air attack and defense, astronomical observation, remote sensing to the ground and the like. The atmosphere external space environment and the atmosphere environment have great difference, and the environment is mainly characterized in that the background temperature of the space environment is extremely low and the background radiation energy is extremely weak. Therefore, in the deep space detection context, the space background radiation is very small, and the optical system becomes the main background radiation of the detector.
The optical system can cause the signal-to-noise ratio of the detected target to be reduced and the contrast of the image to be poor, so that the level of the whole image is reduced, the dynamic range of the image is shortened, the whole gray scale is unevenly distributed, under serious conditions, the detected target signal is submerged, the target signal cannot be identified, or a false signal is detected, the detected target can be lost, the detection efficiency is reduced, and even the whole detection system is invalid.
Therefore, the reduction of the optical system level, namely the reduction of the self heat radiation of the infrared optical system, plays a vital role in improving the signal-to-noise ratio of the system and increasing the detection distance.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an ultra-low self heat radiation long wave infrared optical system, which solves the technical problems of low signal-to-noise ratio, poor image contrast and short system detection distance of a space-based infrared optical detection system.
The technical scheme adopted for solving the technical problems is as follows:
An ultra-low self-heat radiation long wave infrared optical system, comprising the following components in sequence from the light propagation direction: an aperture diaphragm, a primary mirror, a secondary mirror, a field diaphragm, three mirrors, four mirrors, window glass and an image plane; the main mirror, the secondary mirror, the three mirrors and the four mirrors form an off-axis four-return optical lens group; the incident light passes through the aperture diaphragm, is reflected by the off-axis four-return optical lens group, passes through the window glass, forms an image, and receives the radiation energy of the long-wave infrared optical system at the image plane; the field stop is located between the secondary mirror and the tertiary mirror.
Preferably, the detector also comprises a detector hood; three light blocking rings are arranged in the detector light shield, the light passing size of the light blocking rings is determined according to a system view field, an F number and a rear working distance, the light shield is made of aluminum, and the inner surface of the light shield is sprayed with extinction paint with the absorptivity of 99%; light reflected by the off-axis four-return optical lens group is imaged in the detector hood after passing through the window glass.
Preferably, the primary mirror, the secondary mirror, the field stop, the three mirrors and the four mirrors are made of aluminum, and the window glass is made of germanium.
Preferably, the primary mirror is an aspheric surface with an order of 8 times, the secondary mirror is an aspheric surface with an order of 10 times, the third mirror is an aspheric surface with an order of 8 times, and the fourth mirror is an aspheric surface with an order of 10 times.
Preferably, specific parameters of the aperture diaphragm, the primary mirror, the secondary mirror, the field diaphragm, the three mirrors, the four mirrors, the window glass and the image plane are as follows:
| First surface | Radius mm | Caliber mm | Distance of mm | Surface properties | |
| Aperture diaphragm | 1 | ∞ | 280 | 875.652 | |
| Main mirror | 2 | -2798.126 | 330 | -825.652 | Reflection of |
| Secondary mirror | 3 | -370.959 | 50 | 100.000 | Reflection of |
| Visual field diaphragm | 4 | ∞ | 99.118 | Transmission of | |
| Three mirrors | 5 | 555.733 | 70 | -301.590 | Reflection of |
| Four mirrors | 6 | 566.921 | 320 | 839.460 | Reflection of |
| Front surface of window | 7 | ∞ | 40 | 2.500 | Transmission of |
| Rear surface of window | 8 | ∞ | 40 | 60.000 | Transmission of |
| Image plane | 9 | ∞ |
The aspheric coefficients of the four reflecting surfaces are as follows:
2 faces
K 0.6707995524274，
A 3.072262725891e-012，
B 9.255911584931e-018，
C -3.333816204491e-023；
3-Surface
K 6.96947154962414，
A 1.89707230532036e-008，
B 2.63825587402921e-011，
C -3.317642285064e-015，
D 2.276398004164e-019；
5 Faces
K -3.17968924741，
A 1.274319233744e-008，
B 1.973727422323e-013，
C -8.497100764667e-018；
6 Faces
K -0.9634926244527，
A 6.256303291412e-010，
B 1.280997854323e-015，
C -1.965312209617e-022，
D 1.182048406539e-026；
The position relation of the top point of each surface relative to the center coordinate of the aperture diaphragm is as follows:
| First surface | XSC | YSC | ZSC | ASC | BSC | CSC | |
| Aperture diaphragm | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Main mirror | 2 | 0 | -205.971 | 875.653 | 0.000 | 0 | 0 |
| Secondary mirror | 3 | 0 | -246.764 | 50.000 | -26.711 | 0 | 0 |
| Visual field diaphragm | 4 | 0 | -205.971 | 150.000 | 0.000 | 0 | 0 |
| Three mirrors | 5 | 0 | -266.171 | 249.118 | -79.524 | 0 | 0 |
| Four mirrors | 6 | 0 | 156.118 | 410.366 | -112.396 | 0 | 0 |
| Front surface of window | 7 | 0 | -327.225 | 35.871 | -91.440 | 0 | 0 |
| Rear surface of window | 8 | 0 | -325.729 | 23.456 | -91.440 | 0 | 0 |
| Image plane | 9 | 0 | -391.063 | 234.881 | -91.440 | 0 | 0 |
Preferably, the diameter of the system entrance pupil is 280mm, the angle of view is 1.2 degrees, the focal length is 840mm, the wavelength is 8.0 um-12 um, the distortion is less than 1%, and the root mean square diameter of the full-view point list is less than 25um.
Preferably, the gold-plated film and the dielectric protective film on the surfaces of the primary mirror, the secondary mirror, the three mirrors and the four mirrors have the average reflectivity of more than 99.7% in the wave band of 8.0um to 12 um.
Preferably, the front surface of the field diaphragm is sprayed with a light-removing paint with the absorption of 97%, and the back surface is plated with a gold film with the reflectivity of more than 98.5%.
Preferably, structural materials for fixing the aperture diaphragm, the primary mirror, the secondary mirror, the view field diaphragm, the three mirrors, the four mirrors, the window glass, the detector light shield and the image surface are all aluminum.
The beneficial effects of the invention are as follows:
1. The system is an off-axis system, the center is free from shielding, and the system is more beneficial to collecting infrared radiation energy relative to the system.
2. The imaging quality is excellent, and under the conditions that the system parameters are the entrance pupil diameter of 280mm, the field angle of view of 1.2 degrees, the focal length of 840mm, the wavelength of 8.0 um-12 um and the off-axis four-reflection structure is adopted, the distortion is less than 0.1%, and the root mean square diameter of the point column diagram is less than 25um.
3. The aperture diaphragm, the primary mirror, the secondary mirror, the view field diaphragm, the three mirrors, the four mirrors, the detector light shield and the fixed structural member are all made of aluminum, the system is passive and athermal, and the imaging quality can be guaranteed within a wide temperature range of-50 ℃ to 70 ℃.
4. By adopting the measures of off-axis four-reflection structure, controlling the reflectivity of four pieces, adding the view field diaphragm, adding different treatment processes on the front surface and the rear surface of the view field diaphragm, placing the detector light shield and the like, the self heat radiation level of the optical system is greatly reduced, the self heat radiation of the system is as low as 161K, and the system plays a vital role in improving the signal-to-noise ratio of the system and increasing the detection distance.
Drawings
FIG. 1 is a schematic diagram of an ultra-low self-heat radiation long wave infrared optical system.
FIG. 2 is a root mean square plot of a long wave infrared optical system according to an embodiment;
FIG. 3 is a diagram of a distortion of a long-wave infrared optical system in an embodiment;
Fig. 4 is a graph of the correspondence between the equivalent radiation temperature and the radiation flux of the system in the embodiment.
In the figure: 1. the aperture diaphragm, 2, the primary mirror, 3, the secondary mirror, 4, the field diaphragm, 5, three mirrors, 6, four mirrors, 7, window glass, 8, the detector hood, 9, the image plane.
Detailed Description
In order to make the above features and advantages of the present invention more comprehensible, the present invention is described in detail below with reference to the accompanying drawings, but should not be construed to limit the scope of the present invention.
As shown in fig. 1, an ultra-low self-heat radiation long wave infrared optical system comprises: an aperture diaphragm 1, a main mirror 2, a secondary mirror 3, a field diaphragm 4, a three-mirror 5, a four-mirror 6, window glass 7, a detector hood 8 and an image plane 9; the main mirror 2, the secondary mirror 3, the three mirrors 5 and the four mirrors 6 form an off-axis four-return optical lens group; the incident light passes through the aperture diaphragm 1, is reflected by the off-axis four-return optical lens group, passes through the window glass 7, forms an image, and receives the radiation energy of the long-wave infrared optical system at the image plane 9; the field stop 4 is located between the secondary mirror 3 and the tertiary mirror 5. Three light blocking rings are arranged in the detector light shield 8, the light passing size of the light blocking rings is determined according to a system view field, an F number and a rear working distance, the light shield is made of aluminum, and the inner surface of the light shield is sprayed with extinction paint with the absorptivity of 99%; light reflected by the off-axis four-return optical lens group is imaged in the detector hood 8 after passing through the window glass 7.
Wherein the materials of the main mirror 2, the secondary mirror 3, the field stop 4, the three mirrors 5 and the four mirrors 6 are aluminum, and the material of the window glass 7 is germanium. The main mirror 2 is an aspheric surface with the order of 8 times, the secondary mirror 3 is an aspheric surface with the order of 10 times, the three mirrors 5 are aspheric surfaces with the order of 8 times, and the four mirrors 6 are aspheric surfaces with the order of 10 times. The gold plating film and the dielectric protection film on the surfaces of the main mirror 2, the secondary mirror 3, the three mirrors 5 and the four mirrors 6 have the average reflectivity of more than 99.7 percent in the wave band of 8.0um to 12 um. And the front surface of the view field diaphragm 4 is sprayed with a light-removing paint with the absorption of 97 percent, and the back surface is plated with a gold film with the reflectivity of more than 98.5 percent. The structural materials for fixing the aperture diaphragm 1, the main mirror 2, the secondary mirror 3, the view field diaphragm 4, the three mirrors 5, the four mirrors 6, the window glass 7, the detector hood 8 and the image surface 9 are all aluminum.
Table 1 specific parameters of aperture stop, primary mirror, secondary mirror, field stop, three-mirror, four-mirror, window glass, and image plane
| First surface | Radius mm | Caliber mm | Distance of mm | Surface properties | |
| Aperture diaphragm | 1 | ∞ | 280 | 875.652 | |
| Main mirror | 2 | -2798.126 | 330 | -825.652 | Reflection of |
| Secondary mirror | 3 | -370.959 | 50 | 100.000 | Reflection of |
| Visual field diaphragm | 4 | ∞ | 99.118 | Transmission of | |
| Three mirrors | 5 | 555.733 | 70 | -301.590 | Reflection of |
| Four mirrors | 6 | 566.921 | 320 | 839.460 | Reflection of |
| Front surface of window | 7 | ∞ | 40 | 2.500 | Transmission of |
| Rear surface of window | 8 | ∞ | 40 | 60.000 | Transmission of |
| Image plane | 9 | ∞ |
The aspheric coefficients of the four reflecting surfaces are as follows:
2 faces
K 0.6707995524274，
A 3.072262725891e-012，
B 9.255911584931e-018，
C-3.333816204491e-023；
3-Surface
K 6.96947154962414，
A 1.89707230532036e-008，
B 2.63825587402921e-011，
C-3.317642285064e-015，
D 2.276398004164e-019；
5 Faces
K-3.17968924741，
A 1.274319233744e-008，
B 1.973727422323e-013，
C-8.497100764667e-018；
6 Faces
K-0.9634926244527，
A 6.256303291412e-010，
B 1.280997854323e-015，
C-1.965312209617e-022，
D 1.182048406539e-026；
Table 2 positional relationship of the vertices of the surfaces with respect to the center coordinates of the aperture stop
Wherein XSC means X-axis eccentricity, YSC means Y-axis eccentricity, ZSC means Z-axis eccentricity, ASC means rotation about the X-axis, BSC means rotation about the Y-axis, CSC means rotation about the Z-axis.
The ultra-low self heat radiation long wave infrared optical system manufactured by the embodiment is evaluated by adopting the following four evaluation means:
1. Root mean square diameter evaluation of dot column graph
The point map is a point map formed by dividing a pupil plane into a plurality of small cells by an optical path calculation program, and calculating intersections of light rays passing through the cells and the image plane 9. The method has the advantages that the spatial trend of light rays can be known, the spot shape is roughly estimated, the method is a common method for evaluating infrared system target detection, for the designed ultra-low self heat radiation long wave infrared optical system, the root mean square diameter value of the point list of each view field is shown as in fig. 2, the imaging quality can ensure the energy concentration requirement of the long wave infrared system, and therefore the detection of a long-distance target is ensured.
2. Distortion evaluation
Distortion is a phenomenon that when the actual angle amplification rate of the light chief ray is not equal to +1, that is, when the image chief ray is not parallel to the object chief ray, the intersection point of the image chief ray and the ideal image plane is not coincident with the ideal image point. In the case of distortion only, these points fall on a plane perpendicular to the optical axis, but the distance from the optical axis is not right. In the presence of distortion, the image is sharp but has a misalignment. For the designed ultra-low self heat radiation long wave infrared optical system, the distortion value is shown in fig. 3, and the maximum distortion value is 0.1% along with the change of the field of view.
3. Evaluation of self Heat radiation
Definition of equivalent blackbody radiation temperature of an optical system: the ideal blackbody radiation temperature corresponds to the blackbody radiation temperature when the irradiance produced by the optical system on the image plane 9 is equal to the irradiance produced by the infrared optical system on the image plane 9, irrespective of the system thermal radiation.
Assuming that a black body having a temperature T is placed at the entrance pupil of the optical system, the radiation flux generated on the image plane 9 after the black body passes through the optical system is F bb (T), if the influence of aberration or the like is ignored, fbb (T) can be calculated by the following equation:
Wherein τ is the transmittance of the optical system, L is the blackbody radiance, F is the F number of the optical system, and A d is the detector area.
The correspondence between the equivalent radiation temperature and the radiation flux of the system obtained according to the above formula is shown in fig. 4.
And calculating the magnitude of heat radiation stray light of each component on the system image plane 9 based on the heat radiation three-dimensional simulation model. The heat radiation fluxes of the different components at the image plane 9 are shown in table 3.
TABLE 3 thermal radiation flux statistics (W) for each component on image plane
As can be seen from fig. 4, the system equivalent temperature is 161K.
The invention relates to an ultra-low self heat radiation long wave infrared optical system, which mainly comprises an aperture diaphragm 1, a main mirror 2, a secondary mirror 3, a view field diaphragm 4, a three-mirror 5, a four-mirror 6, a window, a detector hood 8 and an image surface 9, wherein the diameter of the system entrance pupil is 280mm, the view field angle is 1.2 degrees, the focal length of the system is 840mm, the wavelength is 8.0-12 um, the distortion is less than 1%, the root mean square diameter of a full view field point list is less than 25um, a four-reflection structure is adopted, the material is aluminum, the system with good image quality is obtained by optimizing the curvature radius, the aspheric coefficient and the thickness parameter of each reflecting surface, the structural parameter meets the practical requirement, and the self heat radiation of the whole system is 161K by adopting a stray light inhibition measure, so that the technical problems of low signal-to-noise ratio, poor image contrast and short system detection distance of the space-based infrared optical detection system are solved.
The foregoing is merely a preferred embodiment of the present invention, and it is apparent that the above embodiment is merely an example of a lens designed for clarity, and not a limitation of the embodiments; other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art; it is not necessary here nor is it exhaustive of all embodiments; while still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.
Claims (9)
1. An ultra-low self heat radiation long wave infrared optical system, which is characterized in that the system comprises the following components in sequence from the light propagation direction: an aperture diaphragm, a primary mirror, a secondary mirror, a field diaphragm, three mirrors, four mirrors, window glass and an image plane; the main mirror, the secondary mirror, the three mirrors and the four mirrors form an off-axis four-return optical lens group; the incident light passes through the aperture diaphragm, is reflected by the off-axis four-return optical lens group, passes through the window glass, forms an image, and receives the radiation energy of the long-wave infrared optical system at the image plane; the field stop is located between the secondary mirror and the tertiary mirror.
2. The ultra-low self-thermal-emission long-wave infrared optical system of claim 1, further comprising a detector mask; three light blocking rings are arranged in the detector light shield, the light passing size of the light blocking rings is determined according to a system view field, an F number and a rear working distance, the light shield is made of aluminum, and the inner surface of the light shield is sprayed with extinction paint with the absorptivity of 99%; light reflected by the off-axis four-return optical lens group is imaged in the detector hood after passing through the window glass.
3. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein the material of the primary mirror, the secondary mirror, the field stop, the three mirrors and the four mirrors is aluminum, and the material of the window glass is germanium.
4. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein the main mirror is an aspheric surface with an order of 8 times, the sub-mirror is an aspheric surface with an order of 10 times, the three mirrors are aspheric surfaces with an order of 8 times, and the four mirrors are aspheric surfaces with an order of 10 times.
5. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein specific parameters of the aperture diaphragm, the primary mirror, the secondary mirror, the field diaphragm, the three mirrors, the four mirrors, the window glass and the image plane are as follows:
The aspheric coefficients of the four reflecting surfaces are as follows:
2 faces
K 0.6707995524274，
A 3.072262725891e-012，
B 9.255911584931e-018，
C -3.333816204491e-023；
3-Surface
K 6.96947154962414，
A 1.89707230532036e-008，
B 2.63825587402921e-011，
C -3.317642285064e-015，
D 2.276398004164e-019；
5 Faces
K -3.17968924741，
A 1.274319233744e-008，
B 1.973727422323e-013，
C -8.497100764667e-018；
6 Faces
K -0.9634926244527，
A 6.256303291412e-010，
B 1.280997854323e-015，
C -1.965312209617e-022，
D 1.182048406539e-026；
The position relation of the top point of each surface relative to the center coordinate of the aperture diaphragm is as follows:
6. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein the system entrance pupil diameter is 280mm, the field angle is 1.2 degrees, the focal length is 840mm, the wavelength is 8.0 um-12 um, the distortion is less than 1%, and the root mean square diameter of the full field point list is less than 25um.
7. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein the primary mirror, secondary mirror, three mirrors and four mirrors are coated with gold and dielectric protective film, and the average reflectivity of the mirror surface is more than 99.7% in the wave band of 8.0 um-12 um.
8. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein the front surface of the field diaphragm is sprayed with a light-absorbing paint with 97% absorption, and the back surface is plated with a gold film with a reflectivity of > 98.5%.
9. The ultra-low self-heat radiation long wave infrared optical system according to claim 1, wherein structural materials for fixing the aperture diaphragm, the primary mirror, the secondary mirror, the field diaphragm, the three mirrors, the four mirrors, the window glass, the detector light shield and the image surface are all aluminum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310523596.2A CN118151355A (en) | 2023-05-10 | 2023-05-10 | Ultra-low self heat radiation long wave infrared optical system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310523596.2A CN118151355A (en) | 2023-05-10 | 2023-05-10 | Ultra-low self heat radiation long wave infrared optical system |
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| Publication Number | Publication Date |
|---|---|
| CN118151355A true CN118151355A (en) | 2024-06-07 |
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ID=91293949
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|---|---|---|---|
| CN202310523596.2A Pending CN118151355A (en) | 2023-05-10 | 2023-05-10 | Ultra-low self heat radiation long wave infrared optical system |
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| Country | Link |
|---|---|
| CN (1) | CN118151355A (en) |
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2023
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