A coaxial four-mirror optical system

Abstract

The coaxial four-mirror optical system provided by the present invention includes a first reflector, a second reflector, a third reflector, a fourth reflector, a primary image plane, a beam splitter, and a first focal plane arranged rotationally symmetrically along the optical axis. And the second focal plane, the light beam emitted by the object at infinite distance in the object side is reflected by the first reflector and enters the second reflector, and then reflected by the second reflector and converged on the primary image plane, the light beam passes through the above-mentioned primary image plane After diverging, it is incident on the third reflector, after being reflected by the third reflector, it is reflected on the fourth reflector, after being reflected by the fourth reflector, it enters the beam splitter, and the beams are respectively converged on the first beam splitter after being split by the beam splitter. On the focal plane and the second focal plane, the present invention adopts a coaxial four-mirror optical system structure, utilizes the multiple folding of the optical path, reduces the total length of the system, and further reduces the tube-to-focal length ratio of the optical system, thereby improving the optical system. Aberration balancing capability.

Description

technical field [0001] The invention relates to the technical field of optical imaging systems, in particular to a coaxial four-reflection optical system. Background technique [0002] With the continuous improvement of space exploration and earth observation requirements, high-resolution imaging puts forward higher requirements on the focal length of space optical payloads. Generally, the longer the focal length, the higher the imaging resolution. The focal length of the current mainstream commercial satellite payloads has been developed to a level of 8-10 meters or higher. For example, the focal length of the IKONOS camera is 10m, and the focal length of the WorldView2 camera reaches 13m. Although a long focal length camera will improve the imaging resolution, it will also cause an increase in the quality and volume of the optical system, and the reflection cost for satellites or missiles will also increase accordingly. Therefore, the light and miniaturized design of the ...

AI Technical Summary

Problems solved by technology

[0005] The existing technology uses three mirrors to balance the aberration of the optical system, which cannot further reduce the tube length of the system and reduce the volume of the optical system while ensuring the imaging quality; the second mirror in the prior art is multiplexed in the imaging optical path , so the manufacturing tolerance of the second reflector is relatively strict; at the same time, the second reflector is a convex quadric surface, and the processing and detection of the convex quadric surface are relatively difficult, which adds a lot of difficulties to the manufacture and surface shape detection of the optical reflector

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