CN204718596U - High resolution camera ADAPTIVE OPTICS SYSTEMS - Google Patents

Abstract

The high-resolution camera adaptive optics system uses a shared primary mirror, a shared secondary mirror, three mirrors, a folding mirror and different focal plane devices to form two optical branches: a visible light high-resolution imaging branch, an automatic Adapt to the wavefront detection branch. The two branches both image the off-axis field of view, and the angle of view of the incident light is different; the visible light high-resolution imaging branch uses the off-axis field of view close to the axis, and the adaptive wavefront detection branch uses the visible light high-resolution The imaging branch has a certain interval of off-axis field of view. The visible light high-resolution imaging branch and the adaptive wavefront detection branch have a relatively fixed wave aberration difference. Through the on-orbit active correction technology, the on-orbit wavefront detection is realized. , On-orbit control calculation and on-orbit wavefront correction. The optical system of the utility model has the advantages of high resolution, high optical-mechanical structure integration, small size, light weight, etc., and has high-resolution imaging of large-scale ground objects, high-precision and high-reliability on-orbit real-time wavefront detection and correction Function.

Description

High-Resolution Camera Adaptive Optics System

technical field

The utility model belongs to the technical field of space optical remote sensors, and relates to a method for realizing an optical imaging system suitable for a high-resolution CCD camera in the visible light near-infrared spectrum and an adaptive wavefront detection function integrated camera.

Background technique

Large aperture and long focal length space cameras are easily affected by factors such as temperature environment, mechanical environment, platform disturbance, etc., resulting in position errors and surface shape errors of optical components, which in turn affect the imaging quality of the optical system. Generally speaking, the larger the aperture of the space camera, the more susceptible it is to be affected by the above factors. When traditional passive methods such as precise thermal control and gravity unloading cannot guarantee the imaging quality of large-aperture optical systems, it is necessary to use on-orbit active aberration correction technology to improve the actual imaging quality.

On-orbit active aberration correction technology mainly includes on-orbit wavefront detection, on-orbit control calculation and on-orbit wavefront correction. Among them, the on-orbit control calculation and on-orbit wavefront correction are very similar to the traditional ground aberration correction system, and relevant test verification can be carried out on the ground. Since the detection beacon of the on-orbit wavefront detection is an extended target of ground objects, and the camera adopts the fast push-broom imaging mode, the on-orbit wavefront detection is quite different from the traditional wavefront detection mode, and the on-orbit aberration active correction On-orbit verification is necessary for the most critical link in the technology.

With the increase in the breadth and depth of space optical remote sensor reconnaissance and surveillance applications, the domestic demand for high-resolution satellites is also gradually increasing, and at the same time, higher and higher resolution requirements are put forward for optical remote sensors. Higher requirements are also put forward for the radiation quality and geometric quality of high-resolution optical remote sensing images. At the same time, with the continuous development of application requirements, the camera is required to have high platform adaptability, and the camera needs to adapt to the wavefront detection technology in the main optical system, so as to effectively improve the image quality.

Since the 1960s, cameras around the world have carried out research on wavefront detection, but so far, there have been few reports on in-orbit applications. The United States was the first to apply wavefront detection instruments to the detection of laser light. In 2009, the Institute of Optoelectronic Technology of the Chinese Academy of Sciences successfully developed a 37-unit solar adaptive optics system, which was successfully applied to the 1m solar telescope in 2011, which significantly increased the contrast of the sun.

The high-resolution imaging CCD camera system using adaptive wavefront detection currently mainly adopts a separate structure, that is, a single high-resolution imaging camera and a wavefront detector. Its outstanding disadvantage is its large volume and weight, which is not conducive to the optimization of the entire star resources. There are few reports of high-resolution cameras with wavefront detection function currently in orbit.

Utility model content

The technical problem solved by the utility model is: to overcome the deficiencies of the prior art, and provide an imaging optical system suitable for a high-resolution CCD camera in the visible light and near-infrared spectrum + an integrated camera with adaptive wavefront detection function.

The technical scheme of the utility model is: a high-resolution camera adaptive optical system, including: a shared primary mirror, a shared secondary mirror, a refracting mirror, three mirrors, a deformable mirror, a visible light high-resolution imaging branch focal plane receiving device, Adaptive wavefront detection branch focal plane receiving device;

The shared primary mirror and the shared secondary mirror are coaxial, and the optical axis of the shared primary mirror and the shared secondary mirror is used as the main optical axis of the optical system; the shared primary mirror is provided with a light hole, and the visible light high-resolution imaging branch and adaptive wave The front detection branch does not share the same field of view, the visible light high-resolution imaging branch uses the off-axis field of view close to the axis, and the adaptive wavefront detection branch uses the off-axis field of view; from the visible light high-resolution imaging branch and the adaptive After being reflected by the common primary mirror and the common secondary mirror, the light beam of the wavefront detection branch reaches the folding mirror through the light hole of the common primary mirror, and reaches the three mirrors after being deflected, and then reaches the Imaging on the focal plane receiving device of the visible light high-resolution imaging branch and the focal plane receiving device of the adaptive wavefront detection branch;

The normals of the refracting mirror and the deforming mirror are located in the meridian plane of the optical system, and the angle between the normal direction of the refracting mirror and the main optical axis is 20° clockwise along the optical axis, and the normal direction of the deforming mirror is in the same direction as The included angle of the main optical axis is 60° clockwise along the optical axis; the focal plane receiving device of the visible light high-resolution imaging branch and the focal plane receiving device of the adaptive wavefront detection branch are integrated on one structural component.

The materials of the shared primary mirror, shared secondary mirror, deflection mirror, deformable mirror, and three mirrors are all silicon carbide or glass-ceramic or fused quartz, and the reflective surfaces of the above-mentioned mirrors are all coated with metal high-reflectivity reflective films .

Compared with the prior art, the utility model has the following advantages:

1) Due to the adoption of the total reflection structure of the common optical path, the utility model realizes the integrated design of high-resolution imaging and high-precision wavefront detection. The two detection devices are integrated in one focal plane structure, and the focal lengths of the two branches are exactly the same. , the wavefront aberration difference value is constant, through high-precision on-orbit wavefront detection, accurate wavefront phase information is obtained, providing information support for on-orbit wavefront correction, realizing active correction of on-orbit aberration, and improving the system’s on-orbit imaging Quality: The system has a simple structure, no color difference, simple processing and assembly, and low engineering difficulty. It solves the problem of poor on-orbit stability and imaging quality of traditional large-aperture long-focus space cameras.

2) The optical system of the utility model corrects the primary image and the secondary aberration simultaneously by controlling the focal power of the main shared secondary mirror, reducing the difficulty of processing and assembly;

3) The high-resolution imaging detection device and the wavefront detection branch detection device of the optical system of the utility model are integrated on a focal plane component, which can be adjusted and tested for the field of view point on the axis of the high-resolution imaging branch of visible light; The PD detector used in the wavefront detection branch uses the same TDICCD as the imaging detector, and the circuit output is consistent, which greatly simplifies the difficulty of system engineering.

4) The utility model has the advantages of good imaging quality, high resolution, compact optical-mechanical structure, simple composition, high integration of optical-mechanical structure, small volume, light weight, etc. It has high-resolution imaging of large-scale ground objects, High-precision and high-reliability on-orbit real-time wavefront detection and correction functions.

Description of drawings

Fig. 1 is the composition structure schematic diagram of the optical system of the present utility model;

Figure 2. Schematic diagram of multi-channel field of view setup.

Detailed ways

The high-resolution camera adaptive optics system is shown in Figure 1, and it is characterized in that it includes: a shared primary mirror 1, a shared secondary mirror 2, a folding mirror 3, a third mirror 4, a deformable mirror 5, and visible light high-resolution imaging branch focal points. Surface receiving device 6 , adaptive wavefront detection branch focal plane receiving device 7 .

Further description is carried out below by specific embodiment:

The working spectrum of the visible light high-resolution imaging branch of the optical system is Pan: 0.45μm～0.89μm, B1: 0.45μm～0.52μm, B2: 0.52μm～0.59μm, B3: 0.63μm～0.69μm, B4: 0.77μm ～0.89μm, focal length is 16000mm, field of view is 0.64°×0.64°, off-field angle is 0.28°～0.32°; the working spectrum and focal length of the adaptive wavefront detection branch are consistent with the high-resolution imaging branch. The two field of view points are located at the edge of the field of view of the visible light high-resolution imaging branch, and the off-field angle is 0.91°.

The two branches share the common primary mirror, the common secondary mirror, the three mirrors and the folding mirror. Among them, the visible light high-resolution imaging branch and the adaptive wavefront detection branch have different fields of view, and the visible light high-resolution imaging branch is close to the The on-axis off-axis field of view object is imaged, and the adaptive wavefront detection branch uses two field of view points in the off-axis field of view close to the high-resolution imaging branch to image. The focal length of the visible near-infrared high-resolution imaging branch is 15m, the full field of view is 2°, and the detector is a TDICCD with a pixel size of 7μm/28μm; the PD detector used in the adaptive wavefront detection branch is the same as the imaging detector The TDICCD.

The light beam from the visible light high-resolution imaging branch is reflected by the shared primary mirror 1 and the shared secondary mirror 2, then passes through the light hole of the shared primary mirror to reach the refracting mirror 3, and then reaches the third mirror 4 and the deformable mirror after being deflected 5. After turning, it reaches the focal plane receiving device 6 of the visible light high-resolution imaging branch; the normal of the turning mirror 3 and the deformable mirror 5 is located in the meridian plane of the optical system, and the included angle with the main optical axis is respectively along the optical axis The hour hand rotates 20° and 60°. Visible light high-resolution imaging branch focal plane receiving device 6 .

After being reflected by the shared primary mirror 1 and the shared secondary mirror 2, the light beam from and adaptive wavefront detection branch passes through the common primary mirror through the light hole to reach the refracting mirror 3, and then reaches the third mirror 4 and the deforming mirror 3 after being deflected. The mirror 5 reaches the focal plane receiving device 7 of the adaptive wavefront detection branch after refraction; the normal line of the refraction mirror 3 and the deformable mirror 5 is located in the meridian plane of the optical system, and the included angle with the main optical axis is respectively along the optical axis Rotate 20° and 60° clockwise.

The focal plane receiving device 6 of the visible light high-resolution imaging branch and the focal plane receiving device 7 of the adaptive wavefront detection branch are integrated on one structural component.

The apertures of the shared primary mirror 1 and the shared secondary mirror 2 are circular symmetry planes, the open optical space of the shared primary mirror is a trapezoidal waist space, and the openings on the front and rear surfaces are rectangular; the three mirrors 4 and the folding mirror 3 and the deformable mirror 5 The clear aperture is rectangular. The materials of the common primary mirror 1, the common secondary mirror 2, the deflection mirror 3, the deformable mirror 5, and the three mirrors 4 are silicon carbide, or glass-ceramic, or fused quartz, and the reflective surface is coated with a metal high-reflectivity reflective film.

The three mirrors 4 of the optical system are fixed on the back of the common main mirror substrate and fixed on the back of the common main mirror 1 substrate, and the folding mirror 3 and the deformable mirror 5 are fixed on the same support structure, which is in the meridian plane and perpendicular to the main optical axis And intersect.

Figure 2 shows the schematic diagram of the field of view settings of the two channels of the optical system. The detector of the visible light high-resolution imaging branch is an area array device; the adaptive wavefront detection branch uses two or more field of view points, and the field of view The point is located near the off-axis of the visible light high-resolution imaging branch, and the receiving device is a small area array device.

The focal plane receiving device 6 of the high-resolution imaging branch of visible light is a linear array multicolor TDICCD detector with a pixel size of 7 μm/28 μm; the receiving device 7 of the adaptive wavefront detection branch is a linear array multicolor detector with a pixel size of 7 μm/28 μm TDICCD detector; the external dimension of the optical system is ￠1300×2500mm ³ .

The content that is not described in detail in the description of the utility model belongs to the known technology of those skilled in the art.

Claims (2)

1. high resolution camera ADAPTIVE OPTICS SYSTEMS, is characterized in that comprising: share primary mirror (1), share secondary mirror (2), refluxing reflection mirror (3), three mirrors (4), distorting lens (5), visible ray high-resolution imaging branch road focal plane receiving device (6), self-adaptation Wavefront detecting branch road focal plane receiving device (7);

Shared primary mirror (1) and shared secondary mirror (2) coaxially, and share the primary optical axis of optical axis as optical system of primary mirror (1) and shared secondary mirror (2); Share primary mirror (1) and be provided with light hole, visible ray high-resolution imaging branch road and self-adaptation Wavefront detecting branch road are not total to visual field, visible ray high-resolution imaging branch road utilizes the outer visual field of the axle on axle, and self-adaptation Wavefront detecting branch road utilizes the outer visual field of axle; After reflecting from visible ray high-resolution imaging branch road and the shared primary mirror (1) of light beam process of self-adaptation Wavefront detecting branch road, shared secondary mirror (2), refluxing reflection mirror (3) is arrived through shared primary mirror light hole, after it is turned back, arrive three mirrors (4), then after three mirrors (4) are turned back, arrive visible ray high-resolution imaging branch road focal plane receiving device (6) and the upper imaging of self-adaptation Wavefront detecting branch road focal plane receiving device (7) respectively;

The normal of refluxing reflection mirror (3) and distorting lens (5) is all positioned at optical system meridian ellipse, and the normal direction of refluxing reflection mirror (3) and primary optical axis angle are turn clockwise 20 ° along optical axis, the normal direction of distorting lens (5) and primary optical axis angle are turn clockwise 60 ° along optical axis; Visible ray high-resolution imaging branch road focal plane receiving device (6) and self-adaptation Wavefront detecting branch road focal plane receiving device (7) are integrated on a structure member.

2. high resolution camera ADAPTIVE OPTICS SYSTEMS according to claim 1, it is characterized in that: described shared primary mirror (1), share secondary mirror (2), refluxing reflection mirror (3), distorting lens (5), three mirrors (4) material be silit or devitrified glass or fused quartz, the reflecting surface of above-mentioned mirror is all coated with metal high reflectance reflectance coating.