Dual field of view common aperture off-axis three-mirror optical system and design method

Abstract

The invention puts forward a dual-field-of-view common-aperture off-axis three-reflecting-mirror optical system and a design method. The optical system comprises a small-field-of-view off-axis three-reflecting-mirror optical system and a big-field-of-view off-axis three-reflecting-mirror optical system, wherein the small-field-of-view off-axis three-reflecting-mirror optical system comprises a main mirror, a secondary mirror, a first turning reflecting mirror, a third mirror, a second turning reflecting mirror, a relay optical system and a detector; and the big-field-of-view off-axis three-reflecting-mirror optical system comprises a correction mirror, a second turning reflecting mirror, a relay optical system and a detector. By use of the optical system, through a way of entering and leaving from the correction mirror, the switching of a big field of view and a small field of view can be realized, an aberration after the big view of field enters the correction mirror is almost the same with the aberration of a small-field-of-view telescope, the design difficulty of the small-field-of-view telescope can be obviously reduced, in addition, the main mirror, the secondary mirror and the third mirror of the telescope all adopt a secondary hook surface, and compared with a high order aspheric surface, the optical system lowers machining and aligning difficulty. The correction mirrorwhere the big field of view enters can carry out aberration matching design with the relay optical system, and therefore, the image quality of the big field of view can be guaranteed to meet use requirements.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to an optical system and a design method, in particular to an off-axis three-mirror optical system with a double field of view and a common aperture and a design method with a punch-in and punch-out correction mirror. Background technique [0002] In order to meet the requirement of farther and farther operating distance of photoelectric instruments, the aperture of photoelectric systems is getting larger and smaller, the field of view is getting smaller and smaller, and the requirements for volume and weight are becoming more and more stringent. Therefore, optoelectronic systems often use large-aperture telescopes to reduce the size and weight of the relay system while meeting the large-aperture requirements. In order to expand the viewing range, it is generally necessary to add a large field of view to meet the search function on the basis of the small field of view. [0003] Tran...

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Problems solved by technology

[0004] Patent U.S.Pat.No.3674334 introduces an off-axis three-mirror optical system, which can solve the problem of central occlusion, but its volume is too large, which limits its use

Patent U.S.Pat.No.5309276 introduces a mirror to turn the optical path on the basis of off-axis three mirrors, which greatly reduces the space size of the system, but it is only a single field of view common optical path design for different sensors

The patent U.S.Pat.No.6970286 B1 can realize multiple fields of view and compress the volume of the system, but the switch between large and small fields of view adopts the method of punching in and out of the plane mirror. If you want to completely share the relay imaging with the large field of view system, the aberration of the three-mirror system on the head needs to be as consistent as possible with the flat plate. Therefore, it brings certain difficulties to the design, and the design result of the three-mirror system is more complicated. The primary mirror, secondary mirror and third mirror all use High-order aspheric surface makes its processing, testing and assembly more difficult

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