阅读说明：本技术 一种大相对孔径高光谱成像光学系统 (High spectral imaging optical system with large relative aperture ) 是由 王保华 唐绍凡 徐彭梅 王伟刚 王杰 张秀茜 陈龙 石峰 贺瑞聪 刘宇翔 王媛媛 于 2021-06-02 设计创作，主要内容包括：本发明公开了一种大相对孔径高光谱成像光学系统,包括：三狭缝组件、平面折转镜、第一透镜、第二透镜、第三透镜、凹面光栅和像面,三狭缝组件用于提升长波红外辐射的入射能量,提高高光谱成像系统的信噪比。目标辐射的长波红外谱段经三狭缝组件入射到平面折转镜,依次经第一透镜、第二透镜和第三透镜透射后,由第三透镜后表面入射到凹面光栅,经凹面光栅色散分光后反射第三透镜后表面,依次经第三透镜、第二透镜和第一透镜透射后汇聚到像面处。本发明可实现长波红外谱段三狭缝狭缝同时高光谱成像,提升长波红外高光谱成像仪的信噪比,具有相对孔径大、狭缝长、体积小、成像质量好等优点,可用于星载、平流层飞艇和机载红外高光谱成像领域。(The invention discloses a large relative aperture hyperspectral imaging optical system, which comprises: the three-slit component is used for improving the incident energy of long-wave infrared radiation and improving the signal-to-noise ratio of the hyperspectral imaging system. The long-wave infrared spectrum band of target radiation enters the plane turning mirror through the three slit components, is transmitted through the first lens, the second lens and the third lens in sequence, enters the concave grating from the rear surface of the third lens, is subjected to chromatic dispersion and light splitting through the concave grating, reflects the rear surface of the third lens, and is converged to the image surface after being transmitted through the third lens, the second lens and the first lens in sequence. The invention can realize simultaneous hyperspectral imaging of three slits of a long-wave infrared spectrum band, improves the signal-to-noise ratio of the long-wave infrared hyperspectral imager, has the advantages of large relative aperture, long slit, small volume, good imaging quality and the like, and can be used in the field of spaceborne, stratospheric airship and airborne infrared hyperspectral imaging.)

1. A large relative aperture hyperspectral imaging optical system is characterized by comprising: the three-slit optical lens comprises a three-slit component (E1), a plane turning mirror (E2), a first lens (E3), a second lens (E4), a third lens (E5), a concave grating (E6) and an image plane (E7); wherein the content of the first and second substances,

the long-wave infrared of target radiation simultaneously enters a plane turning mirror (E2) through a three-slit assembly (E1), is reflected and then enters a first lens (E3), is transmitted through a front surface (S1) and a rear surface (S2) of the first lens (E3) and then enters a second lens (E4), is transmitted through a front surface (S3) and a rear surface (S4) of the second lens (E4) and then enters a third lens (E5), is transmitted through a front surface (S5) and a rear surface (S6) of the third lens (E5) and then enters a concave grating (E6), is dispersed and dispersed by the concave grating (E6) and then is reflected to a rear surface (S6) of the third lens (E5), and is transmitted through the third lens (E5), the second lens (E4) and the first lens (E3) and then is imaged to an image plane (E7).

2. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the range of the long-wave infrared spectrum band is 8-12.5 mu m, and the spectral resolution is 100 nm.

3. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the large-relative-aperture hyperspectral imaging optical system has the relative aperture of 1/2 and the spatial magnification of 1.

4. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the three-slit component (E1) is formed by arranging 3 identical single-light-passing slit devices in parallel; wherein, the length of each single light-passing slit device is 24mm, and the width is 32 μm; the spacing between adjacent single light slit means is 1.6 mm.

5. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the plane turning mirror (E1) is made of aluminum and is placed at an angle of 45 degrees with the incident light.

6. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the material of the first lens (E3) is ZnS, the front surface (S1) of the first lens (E3) is a sextuple aspheric surface, and the rear surface (S2) of the first lens (E3) is a spherical surface.

7. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the material of the second lens (E4) is ZnSe, the front surface (S3) of the second lens (E4) is a sextuple aspheric surface, and the rear surface (S4) of the second lens (E4) is a spherical surface.

8. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the material of the third lens (E5) is ZnS, the front surface (S5) of the third lens (E5) is a sextuple aspheric surface, and the rear surface (S6) of the third lens (E5) is a spherical surface.

9. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: and the surface of the concave grating (E6) is etched with a blazed groove and plated with a gold film.

10. The large relative aperture hyperspectral imaging optical system according to claim 1, wherein: the image plane (E3) is composed of 3 regions, each region has an area of 24mm × 1.44mm, and the interval between the three regions is 0.16 mm.

Technical Field

The invention belongs to the technical field of infrared hyperspectral imaging, and particularly relates to a large-relative-aperture hyperspectral imaging optical system.

Background

The hyperspectral imager can simultaneously obtain two-dimensional space information and one-dimensional spectral information of a target, long-wave infrared hyperspectral imaging can be used for target detection, quantitative analysis can be realized through spectral component identification, and application requirements on the aspects of high-precision temperature inversion, atmospheric pollution monitoring, geological disaster monitoring and the like are urgent. At present, the working spectrum of a hyperspectral imager is mostly concentrated on a visible near-infrared spectrum band (0.4-1.0 mu m) and a short-wave infrared spectrum band (1.0-2.5 mu m), the hyperspectral imaging for a long-wave infrared spectrum band is less, and the performance requirements of hyperspectral resolution, high spatial resolution and high-temperature resolution cannot be met at the same time, and the traditional design method causes the volume of a long-wave infrared hyperspectral imaging optical system to be larger, and the use requirement of a smaller platform cannot be met.

Disclosure of Invention

The technical problem solved by the invention is as follows: the defects of the prior art are overcome, the large-relative-aperture hyperspectral imaging optical system is provided, and the large-relative-aperture hyperspectral imaging optical system has the characteristics of high energy utilization rate, large relative aperture, long slit and small size and meets various remote sensing application requirements.

The purpose of the invention is realized by the following technical scheme: a large relative aperture hyperspectral imaging optical system comprising: the three-slit optical lens comprises a three-slit component, a plane turning mirror, a first lens, a second lens, a third lens, a concave grating and an image plane; the long-wave infrared of the target radiation enters the plane turning mirror through the three slit assemblies at the same time, enters the first lens after being reflected, enters the second lens after being transmitted by the front surface and the rear surface of the first lens, enters the third lens after being transmitted by the front surface and the rear surface of the second lens, enters the concave grating after being transmitted by the front surface and the rear surface of the third lens, is reflected to the rear surface of the third lens after being subjected to dispersion and light splitting by the concave grating, and is imaged to an image surface after being transmitted by the third lens, the second lens and the first lens in sequence.

In the large relative aperture hyperspectral imaging optical system, the range of the long-wave infrared spectrum band is 8-12.5 microns, and the spectral resolution is 100 nm.

In the large relative aperture hyperspectral imaging optical system, the relative aperture of the large relative aperture hyperspectral imaging optical system is 1/2, and the spatial magnification is 1.

In the large-relative-aperture hyperspectral imaging optical system, the three-slit component is formed by arranging 3 identical single-pass light slit devices in parallel; wherein, the length of each single light-passing slit device is 24mm, and the width is 32 μm; the spacing between adjacent single light slit means is 1.6 mm.

In the large-relative-aperture hyperspectral imaging optical system, the plane turning mirror is made of aluminum and is placed at an angle of 45 degrees with incident light.

In the large-relative-aperture hyperspectral imaging optical system, the first lens is made of ZnS, the front surface of the first lens is a sextuple aspheric surface, and the rear surface of the first lens is a spherical surface.

In the large-relative-aperture hyperspectral imaging optical system, the second lens is made of ZnSe, the front surface of the second lens is a sextuple aspheric surface, and the rear surface of the second lens is a spherical surface.

In the large-relative-aperture hyperspectral imaging optical system, the third lens is made of ZnS, the front surface of the third lens is a sextuple aspheric surface, and the rear surface of the third lens is a spherical surface.

In the high spectral imaging optical system with the large relative aperture, the surface of the concave grating is etched with a blazed groove and is plated with a gold film.

In the large-relative-aperture hyperspectral imaging optical system, the image surface consists of 3 regions, the area of each region is 24mm multiplied by 1.44mm, and the interval between the three regions is 0.16 mm.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention has the characteristics of high energy utilization rate, large relative aperture, long slit and small volume, and can meet the requirements of various remote sensing applications;

(2) the system can realize the hyperspectral imaging of the spectrum band range of long-wave infrared 8-12.5 microns, the spectral resolution is 100nm, and the spectrum bands are 45, solves the problem that the existing long-wave infrared imaging spectrum bands are few, and effectively meets the application requirements of a plurality of fields on the long-wave infrared hyperspectral imaging;

(3) the relative aperture of the system is 1/2, the three-incidence slit is adopted to further improve the long-wave infrared radiation energy collection capability, the simultaneous hyperspectral imaging of the three-incidence slit is realized, and the temperature resolution of the infrared hyperspectral imaging system is greatly improved;

(4) the system has the volume phi of 44mm multiplied by 90mm, has the advantages of simplicity, compactness and miniaturization, is beneficial to realizing the light weight design of the system, reduces the power consumption required by refrigeration, and meets the use requirements of a plurality of remote sensing platforms.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic diagram of a large relative aperture hyperspectral imaging optical system provided by an embodiment of the invention;

FIG. 2 is a schematic diagram of a spatial layout of a three-slit assembly according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an image distribution on an image plane according to an embodiment of the present invention;

FIG. 4(a) is a dot array diagram of imaging region 1 at 8 μm, 10.25 μm and 12.5 μm wavelengths provided by an embodiment of the present invention;

FIG. 4(b) is a plot of the imaged area 2 at 8 μm, 10.25 μm and 12.5 μm wavelengths as provided by an embodiment of the present invention;

FIG. 4(c) is a dot array diagram of imaging region 3 at 8 μm, 10.25 μm, and 12.5 μm wavelengths provided by an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1, the present embodiment provides a long-wave infrared three-slit Dyson hyperspectral imaging optical system, a relative aperture is 1/2, a working spectral band is 8 μm to 12.5 μm, a spectral resolution is 100nm, and the system includes a three-slit assembly E1, a plane turning mirror E2, a first lens E3, a second lens E4, a third lens E5, a concave grating E6, and an image plane E7.

The long-wave infrared of the target radiation is simultaneously incident to a plane turning mirror E2 through a three-slit assembly E1, is incident to a first lens E3 after being reflected, is incident to a second lens E4 after being transmitted by a front surface S1 and a rear surface S2 of the first lens E3, is incident to a third lens E5 after being transmitted by a front surface S3 and a rear surface S4 of the second lens E4, is incident to a concave grating E6 after being transmitted by a front surface S5 and a rear surface S6 of the third lens E5, is dispersed and split by the concave grating E6 and then reflected to the rear surface S6 of the third lens E5, is sequentially transmitted by the third lens E5, the second lens E4 and the first lens E3 and then imaged to an E image plane 7, and the incident light passes through the first lens E3 twice, the second lens E4 and the third lens E5 realize 8-12.5 mu m spectral band hyperspectral imaging, the spectral resolution is 100nm, the dispersion range of a single-pass light incident slit image is 1.44mm, and the total distribution range on an image plane is 4.64 mm.

By optimizing the aspherical coefficients of the surfaces of the first lens, the second lens and the third lens, the vertex curvature radius and the interval between the elements, the imaging quality of the optical system approaches the diffraction limit, and the volume of the system is compressed to be phi 44mm x 90 mm.

The plane turning mirror is made of aluminum, the surface of the plane turning mirror is plated with a reflection increasing film, and the reflectivity in the spectral range of 8-12.5 mu m is more than 98.5 percent.

The first lens and the third lens are made of ZnS, antireflection films are respectively coated on the front surface and the rear surface, and the reflectivity in the spectral range of 8-12.5 mu m is more than 98.5%.

The material of the second lens is ZnSe, the front and back surfaces are coated with antireflection films, and the reflectivity in the spectral range of 8-12.5 μm is more than 98.5%.

The length direction of the grooves is parallel to the system sagittal direction, the groove density is 6.3lp/mm, the diffraction order is 1, the efficiency of the surface gold-plated film in the spectral range of 8-12.5 mu m is more than 70%.

As shown in fig. 2, the three-slit assembly is composed of 3 single-pass light slits arranged in parallel, which are slit 3, slit 2 and slit 1 along the + Y direction, and the height of the center of each light-pass slit in the Y direction is-1.6 mm, 0mm and 1.6mm, respectively. The single clear slit has a length of 24mm and a width of 32 μm, and the total width of the three slit assembly is 3.2 mm.

As shown in fig. 3, the image plane of the long-wave infrared radiation imaged by the optical system is composed of 3 imaging regions, which are an imaging region 1, an imaging region 2, and an imaging region 3 along the + Y direction, wherein the imaging region 1 corresponds to the imaging spectrum plane of the light-transmitting slit 3, the imaging region 2 corresponds to the imaging spectrum plane of the light-transmitting slit 2, and the imaging region 3 corresponds to the imaging spectrum plane of the light-transmitting slit 1. The length of each imaging area was 24mm, the width was 1.44mm, and the spacing between imaging areas was 0.16 mm.

As shown in fig. 4(a), 4(b) and 4(c), the imaging quality of the long-wavelength infrared radiation after being imaged by the optical system is close to the diffraction limit.

FIG. 4(a) is a graph showing dot arrays of the imaging region 1 at 8 μm, 10.25 μm and 12.5 μm wavelengths.

FIG. 4(b) is a graph showing dot arrays of the imaging region 2 at 8 μm, 10.25 μm and 12.5 μm wavelengths.

FIG. 4(c) is a graph showing dot arrays of the imaging region 3 at 8 μm, 10.25 μm and 12.5 μm wavelengths.

TABLE 1 design parameters of long-wave infrared three-slit Dyson hyperspectral imaging optical system

The invention has the characteristics of high energy utilization rate, large relative aperture, long slit and small volume, and can meet the requirements of various remote sensing applications; the system can realize the hyperspectral imaging of the spectrum band range of long-wave infrared 8-12.5 microns, the spectral resolution is 100nm, and the spectrum bands are 45, solves the problem that the existing long-wave infrared imaging spectrum bands are few, and effectively meets the application requirements of a plurality of fields on the long-wave infrared hyperspectral imaging; the relative aperture of the system is 1/2, the three-incidence slit is adopted to further improve the long-wave infrared radiation energy collection capability, the simultaneous hyperspectral imaging of the three-incidence slit is realized, and the temperature resolution of the infrared hyperspectral imaging system is greatly improved; the system has the volume phi of 44mm multiplied by 90mm, has the advantages of simplicity, compactness and miniaturization, is beneficial to realizing the light weight design of the system, reduces the power consumption required by refrigeration, and meets the use requirements of a plurality of remote sensing platforms.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.