An off-axis reflective imaging optical system

Abstract

The invention relates to an off-axis reflective imaging optical system. The apexes of a first main reflector, a second auxiliary reflector and a third reflector are all on an optical axis of the system and used in an off-axis mode; the first main reflector and the third reflector are of spherical surfaces, and the second auxiliary reflector and a fourth reflector are of aspheric surfaces; the first main reflector converges the incident light beam reflected by the entrance pupil onto the surface of the first main reflector to reduce the diameter of the incident light beam; the second auxiliary reflector refracts the light beam converged by the first main reflector and corrects some spherical and comatic aberration generated by the first main reflector; the third reflector further refracts the light beam converged by the second auxiliary reflector and corrects some astigmatism and curvature of the field, which are led by a second main reflector; the fourth reflector refracts the light beam converged by the third reflector, leads aberration for balancing the aberration of the system, and enables the light beam to be imaged on the image plane. The off-axis reflective imaging optical system has the advantages of being long in focal length, large in image plane, less in the number of aspheric surfaces and good in imaging quality. And optical elements of the system are low in producing difficulty.

Description

technical field [0001] The invention relates to the technical field of imaging optical systems working in the ultraviolet band to infrared band, in particular to an off-axis reflective imaging optical system. Background technique [0002] The off-axis three-mirror-anastigmat (TMA: Three-Mirror-Anastigmat) optical system is widely used in space optics, earth observation, astronomical optics, etc. It has been applied, and many countries are studying it. [0003] At the same time, this optical system also has a relatively large disadvantage, that is, it has high requirements for processing, testing and assembly. In terms of processing, the three reflective surfaces of this optical system are all high-order aspheric surfaces, which are difficult to process and detect. It is more difficult in the adjustment and adjustment, and it is necessary to study the computer-aided adjustment technology. [0004] Through decades of research, this optical system has evolved into many forms...

AI Technical Summary

Problems solved by technology

However, since the primary mirror is a free-form surface, the third mirror is a high-even-order aspheric surface, and the diameters of the two mirrors are relatively large, it is difficult to process, especially on large-diameter mirrors with optical power. curved surface

Images