阅读说明：本技术 一种用于能量探测的大视场离轴三反光学系统 (Large-view-field off-axis three-mirror optical system for energy detection ) 是由 谢远 王臣臣 田晓 张蕾 于 2021-08-11 设计创作，主要内容包括：本发明设计一种用于能量探测的大视场离轴三反光学系统。其特别之处在于：沿着光线传播方向依次包括第一反射镜、第二反射镜、第三反射镜；光阑位于第一反射镜上；第一反射镜、第二反射镜、第三反射镜均有离轴和倾斜；视场采用圆形视场,全视场大小为4.8°；系统长度为焦距大小的一半左右；第一反射镜、第二反射镜、第三反射镜的面型均为非球面结构；系统产生的像点大小在3μm大小的能量分布达到百分之八十以上。本发明提供了一种能够用于空间星系能量探测,实现紫外到短波红外波段成像,能够将高达80％以上的能量集中与产生的像点大小的3μm范围内的能量探测系统。(The invention designs a large-view-field off-axis three-mirror optical system for energy detection. It is characterized in that: the device comprises a first reflector, a second reflector and a third reflector in sequence along the light propagation direction; the diaphragm is positioned on the first reflector; the first reflector, the second reflector and the third reflector are all off-axis and inclined; the field of view adopts a circular field of view, and the size of the full field of view is 4.8 degrees; the length of the system is about half of the focal length; the surface types of the first reflector, the second reflector and the third reflector are all aspheric structures; the system produces an energy distribution with a spot size of 3 μm of more than eighty percent. The invention provides an energy detection system which can be used for space star system energy detection, realizes imaging from ultraviolet to short wave infrared bands, and can concentrate more than 80% of energy and generate image points within 3 mu m.)

1. A large field of view off-axis three-mirror optical system for energy detection, said optical system comprising a first mirror, a second mirror, a third mirror;

the optical system sequentially passes through the first reflector, the second reflector and the third reflector along the light propagation direction;

the diaphragm is positioned on the first reflector;

the mirror surfaces of the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are all aspheric mirrors;

the first reflector and the second reflector are oppositely arranged, the second reflector and the third reflector are oppositely arranged, and the first reflector and the third reflector are respectively arranged at two sides of the second reflector;

the first reflector, the second reflector and the third reflector are arranged in an off-axis and inclined mode.

2. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the whole length of the optical system is 0.35-0.65 of the focal length of the optical system.

3. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the optical system adopts a circular view field, and the size of the full view field is 6.5-8 degrees.

4. The large field of view off-axis three-mirror optical system for energy detection of claim 1, wherein: the optical characteristics of the first reflecting lens are as follows: -0.85 f' < f₁′＜-0.75f′，-1.7f′＜R₁＜-1.5f′，-0.75＜k₁＜-0.7，-1.78e-12＜k₁₄＜-1.7e-12，-7.5e-19＜k₁₆＜-7e-19，-1.5e-24＜k₁₈＜-1.0e-24，-5.0e-31＜k₁₁₀＜-5.5e-31，-420＜d_1y＜-400，-2°＜α_1y＜-1°；

The optical characteristics of the second mirror are: -0.25 f' < f₂′＜-0.20f′，-0.5f′＜R₂＜-0.4f′，-5.2＜k₂＜-4.8，1.2e-8＜k₂₄＜1.4e-8，-1.2e-12＜k₂₆＜-1.1e-12，3.5e-17＜k₂₈＜4.0e-17，-420＜d_2y＜-400，1°＜α_2y＜2°；

The optical characteristics of the third reflector are as follows: -0.45 f' < f₃′＜-0.35f′，-0.9f′＜R₃＜-0.7f′，-0.05＜k₃＜-0.04，-2.5e-11＜k₃₄＜-2.0e-11，-5.0e-17＜k₃₆＜-4.0e-17，-8.0e-27＜k₃₈＜-7.0e-27，3.0e-28＜k₃₁₀＜4.0e-28，-300＜d_3y＜-250，9°＜α_3y＜10°；

Wherein f' is the system focal length; f. of₁′、f₂′、f₃′、f₄' are focal lengths; k is a radical of₁Is the second order coefficient of the first reflector; k is a radical of_n4，k_n6，k_n8，k_n10The coefficients are four times, six times, eight times and ten times respectively; r₁、R₂、R₃Three curvature radiuses corresponding to the reflector; d is the Lexin size of each sub-mirror along the y-axis direction; alpha is the size of the inclination angle of the reflector.

5. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the first mirror, the second mirror, and the third mirror are all decentered along the y-axis, with the maximum amount of decentration being less than half of the focal length.

6. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the first, second and third mirrors are rotated along the x-axis by a maximum rotation angle of less than 10 °.

7. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the reflector of the optical system adopts a centrifugal design, and large-range target detection is realized.

8. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the energy of an imaging point of the optical system on a focal plane is more than 80% in a range of 3 mu m.

9. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the focal length of the optical system is 850-900mm, and the aperture of the system is 280-320 mm.

10. A large field of view off-axis three-mirror optical system for energy detection as claimed in claim 1, wherein: the imaging spectral band of the optical system covers 0.45-0.85 μm.

Technical Field

The invention relates to the field of optical imaging, in particular to a large-view-field off-axis three-mirror optical system for energy detection. The method is mainly used in the fields of energy detection of remote galaxies and the like.

Technical Field

With the continuous deepening of space exploration, the demands of space flight and aviation on optical systems are continuously increased, and on one hand, the demands for space optical systems with higher resolution and higher sensitivity are more and more urgent and are used for acquiring more detailed information of a detected target; on one hand, the problems that the detection dynamic range of the optical energy detection unit is small, the function is single, the structural design is unreasonable, physical interference is easy to occur with the structure of an optical system and the like need to be overcome. However, there has been no related research on an optical system of a large field of view for energy detection, and it is necessary to develop an optical system of a large field of view for energy detection.

The detection optical system has wide application, and the sensitivity and the timeliness are important performance indexes. The principle is based on Rayleigh criterion, the larger the caliber is, the higher the resolution is, the illumination intensity received by the system can be improved by designing the large caliber, and then the system is more sensitive to the light emitted by a weak target, and the detection sensitivity is improved; and the large field of view can search the target in a large range, and the detection timeliness is improved. Compared with the sensitivity, the detection target can be quickly found in the field of view, and the improvement of the timeliness is an important function of the detection system, so that the large field of view is the design trend of the detection optical system.

The star sensor is a high-precision space attitude measuring instrument widely used in a spacecraft, and acquires attitude information of a carrier by detecting star radiation at different positions in a celestial body. The optical system is a core component of the star sensor, and the quality of the design of the optical system determines the quality of a received star image point, so that the speed of the subsequent processing process of the system and the positioning accuracy are influenced. Therefore, the research on the design of the star sensor lens has important research significance. While refractive and reflective are the main forms of optical systems as the main forms of optical design. Due to the limitation of small volume, light weight and the like, the star sensor of a long-focus and large-caliber system mainly adopts a reflection type structure. The field of view of the reflective optical system is generally small, is second-order, and cannot meet the actual requirement of large-field-of-view imaging, so that the system structure needs to be readjusted to meet the requirement of actual large-field-of-view searching.

The invention provides an off-axis three-mirror energy detection system which can be used for space star system energy detection, realizes imaging from ultraviolet to short wave infrared bands and concentrates 80% of energy and generates image points within a range of 3 mu m, aiming at the design requirement of a large-field reflective optical system, considering that the system can better correct aberrations, improve the field of view of the system, expand the search range and effectively collect and utilize band energy.

Disclosure of Invention

In view of this, the invention provides a large-view-field off-axis three-mirror optical system for energy detection, which can improve the view field size and imaging quality of a reflection system, so that the system can perform energy detection.

A large field of view off-axis three-mirror optical system for energy detection, said optical system comprising a first mirror, a second mirror, a third mirror; the optical system sequentially passes through the first reflector, the second reflector and the third reflector along the light propagation direction; the diaphragm is positioned on the first reflector; the mirror surfaces of the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are all aspheric mirrors; the first reflector and the second reflector are oppositely arranged, the second reflector and the third reflector are oppositely arranged, and the first reflector and the third reflector are respectively arranged at two sides of the second reflector; the first reflector, the second reflector and the third reflector are arranged in an off-axis and inclined mode.

The whole length of the optical system is 0.35-0.65 of the focal length of the optical system.

The optical system adopts a circular view field, and the size of the view field is 6.5-8 degrees.

The optical characteristics of the first reflecting lens are as follows: -0.85 f' < f₁′＜-0.75f′，-1.7f′＜R₁＜-1.5f′，-0.75＜k₁＜-0.7，-1.78e-12＜k₁₄＜-1.7e-12，-7.5e-19＜k₁₆＜-7e-19，-1.5e-24＜k₁₈＜-1.0e-24，-5.0e-31＜k₁₁₀＜-5.5e-31，-420＜d_1y＜-400，-2°＜α_1y＜-1°；

The optical characteristics of the second mirror are: -0.25 f' < f₂′＜-0.20f′，-0.5f′＜R₂＜-0.4f′，-5.2＜k₂＜-4.8，1.2e-8＜k₂₄＜1.4e-8，-1.2e-12＜k₂₆＜-1.1e-12，3.5e-17＜k₂₈＜4.0e-17，-420＜d_2y＜-400，1°＜α_2y＜2°：

The optical characteristics of the third reflector are as follows: -0.45 f' < f₃′＜-0.35f′，-0.9f′＜R₃＜-0.7f′，-0.05＜k₃＜-0.04，-2.5e-11＜k₃₄＜-2.0e-11，-5.0e-17＜k₃₆＜-4.0e-17，-8.0e-27＜k₃₈＜-7.0e-27，3.0e-28＜k₃₁₀＜4.0e-28，-300＜d_3y＜-250，9°＜α_3y＜10°；

Wherein f' is the system focal length; f. of₁′、f₂′、f₃′、f₄' are focal lengths; k is a radical of₁Is the second order coefficient of the first reflector; k is a radical of_n4，k_n6，k_n8，k_n10The coefficients are four times, six times, eight times and ten times respectively; r₁、R₂、R₃Three curvature radiuses corresponding to the reflector; d is the Lexin size of each sub-mirror along the y-axis direction; alpha is the size of the inclination angle of the reflector.

The first mirror, the second mirror, and the third mirror are all decentered along the y-axis, with the maximum amount of decentration being less than half of the focal length.

The first, second and third mirrors are rotated along the x-axis by a maximum rotation angle of less than 10 °.

The reflector of the optical system adopts a centrifugal design, and large-range target detection is realized.

The energy of an imaging point of the optical system on a focal plane is more than 80% in a range of 3 mu m.

The focal length of the optical system is 850-900mm, and the aperture of the system is 280-320 mm.

Compared with the prior art, one of the technical schemes has the following advantages or beneficial effects: the system adopts an aspherical mirror, the degree of freedom of correcting the aberration of the optical system is increased, an optical system with good imaging quality is obtained by optimizing a quadratic coefficient and an aspherical coefficient, and a transfer function curve of the system is close to a diffraction limit in the full field of view;

another technical scheme in the above technical scheme has the following advantages or beneficial effects: the full field of view of the reflective optical system can be increased to about 7 ° and the half field of view can be increased to about 4.8 ° by various means.

Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a large field of view off-axis three-mirror optical system for energy detection according to an embodiment of the present invention;

FIG. 2 is a diagram of the energy of a bounding circle of an optical system provided by one embodiment of the present invention;

FIG. 3 is a dot-column diagram of an off-axis three-mirror system provided by an embodiment of the present invention;

FIG. 4 is a graph of a transfer function of an off-axis three-mirror system according to an embodiment of the present invention;

wherein, in the figure: 1. a primary mirror; 2. a secondary mirror; 3. three mirrors;

Detailed Description

For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.

It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Aiming at the defect that the size of a system view field cannot meet the actual requirement, an off-axis aspheric reflective optical system is adopted, the size of the system view field is increased, the effective collection and utilization of band energy are completed, and the energy detection system which can be used for space star system energy detection, realizes imaging from ultraviolet to short wave infrared bands and can concentrate more than 80% of energy to an imaging point range lower than 3 microns is provided.

As shown in fig. 1, a large-view-field off-axis three-mirror optical system for energy detection sequentially comprises a primary mirror 1, a secondary mirror 2 and a tertiary mirror 3 along a light propagation direction, wherein the primary mirror 1, the secondary mirror 2 and the tertiary mirror 3 are all reflectors, and the mirror surface of each reflector is an aspherical mirror; the first reflector (i.e. the primary mirror 1) is arranged opposite to the second reflector (i.e. the primary mirror 2), the second reflector (i.e. the primary mirror 2) is arranged opposite to the third reflector (i.e. the primary mirror 3), and the first reflector and the third reflector are respectively arranged at two sides of the second reflector.

The first reflector, the second reflector and the third reflector are arranged in an off-axis and inclined mode; the whole length of the optical system is 0.35-0.65 of the focal length of the optical system; the optical system adopts a circular view field, and the size of the full view field is between 6.5 and 8 degrees.

The optical characteristics of the first reflective lens (i.e., the primary mirror 1) are: -0.85 f' < f₁′＜-0.75f′，-1.7f′＜R₁＜-1.5f′，-0.75＜k₁＜-0.7，-1.78e-12＜k₁₄＜-1.7e-12，-7.5e-19＜k₁₆＜-7e-19，-1.5e-24＜k₁₈＜-1.0e-24，-5.0e-31＜k₁₁₀＜-5.5e-31，-420＜d_1y＜-400，-2°＜α_1y< -1 °; the optical properties of the second mirror (i.e. the primary mirror 2) are: -0.25 f' < f₂′＜-0.20f′，-0.5f′＜R₂＜-0.4f′，-5.2＜k₂＜-4.8，1.2e-8＜k₂₄＜1.4e-8，-1.2e-12＜k₂₆＜-1.1e-12，3.5e-17＜k₂₈＜4.0e-17，-420＜d_2y＜-400，1°＜α_2yLess than 2 degrees; the optical properties of the third mirror (i.e. the primary mirror 3) are: -0.45 f' < f₃′＜-0.35f′，-0.9f′＜R₃＜-0.7f′，-0.05＜k₃＜-0.04，-2.5e-11＜k₃₄＜-2.0e-11，-5.0e-17＜k₃₆＜-4.0e-17，-8.0e-27＜k₃₈＜-7.0e-27，3.0e-28＜k₃₁₀＜4.0e-28，-300＜d_3y＜-250，9°＜α_3yLess than 10 degrees; wherein f' is the system focal length; f. of₁′、f₂′、f₃′、f₄' are focal lengths; k is a radical of₁Is the second order coefficient of the first reflector; k is a radical of_n4，k_n6，k_n8，k_n10The coefficients are four times, six times, eight times and ten times respectively; r₁、R₂、R₃Three curvature radiuses corresponding to the reflector; d is the Lexin size of each sub-mirror along the y-axis direction; alpha is the size of the inclination angle of the reflector.

The first reflector, the second reflector and the third reflector are all eccentric along the y axis, and the maximum eccentric amount is less than half of the focal length; the first reflector, the second reflector and the third reflector rotate along the x-axis, and the maximum rotation angle is less than 10 degrees; the reflector of the whole optical system adopts a centrifugal design, and the size of the full field of view is 6.5-8 degrees, so that the whole optical system can realize large-range target detection.

Under the condition that the whole system cannot correct aberration, a bright spot with a certain size is formed on a focal plane after light is transmitted by the optical system, the size of the bright spot formed by the three reflectors can be used for analyzing the imaging quality of the system, and the smaller the size is, the better the imaging quality of the system is.

The focal length of the whole optical system is controlled to be 850-900mm, the aperture of the system is 280-320 mm, and finally the energy of an imaging point on a focal plane within a range of 3 mu m is more than 80%, and if the energy of the imaging point on the focal plane within a range of 7 mu m is more than 90%.

Example 1:

referring to fig. 1, which is a schematic diagram of the optical system of the present invention, the system is composed of three mirrors, each of which is decentered along the y-axis and rotated along the x-axis. The incident light is reflected by the first reflector after being incident to the system, is incident to the second reflector and finally reaches the image surface of the system through the third reflector.

The focal length of the optical system provided by the embodiment is 850-. As shown in fig. 2, in the visible light band, MTF is close to the diffraction limit in the full field range, the image point formed on the focal plane by the system is in the range of 3 μm, the energy concentration ratio is 80% or more, and 90% or more in the range of 7 μm.

The optical system adopts the design of centrifuging and inclining the reflector, so that the field of view of the system can be increased, and meanwhile, the non-spherical surface type is selected for the mirror surface of the reflector, so that the degree of freedom of the system in optimizing various aberrations is increased, and the imaging quality of the system is improved. For the dot alignment of the system (as shown in FIG. 3), the MTF curve (as shown in FIG. 2), etc., it can be seen that the imaging quality of the centrifugal three-mirror system is already close to the diffraction limit, and more than 80% of the energy can be focused to the range of 3 μm.

The above provides a detailed description of a large-field off-axis three-mirror optical system for energy detection according to an embodiment of the present application. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. The term "comprising", without further limitation, means that the element so defined is not excluded from the article or system in which the element is included.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.