Compact Dyson imaging spectrometer with large working distance using freeform surface

摘要

The most significant shortage of the Dyson spectrometer is that the small clearance among the slit, image plane and the hemisphere lens makes the spectrometer difficult to assembly. To solve this problem, several approaches have been proposed. Such as inserting additional aspherical lenses in the optical path to enlarge the image distance, or using a fused silica lens and incorporates a built-in fold mirror to allow the detector sufficient clearance from the slit. In this paper, a Dyson imaging spectrometer with freeform surface has been designed. The freeform surface is used to enlarge clearance distance and compensate the large residual aberration without additional lenses. The design starts from a sphere Dyson system, and then the freeform surfaces are applied to optimize the initial configuration by the use of optical software. The design results show that the Dyson imaging spectrometer with freeform surfaces have great optical performance and easy to mounting which is crucial for development in the fields of aeronautics and astronautics remote sensing.