Design of Off-axis Three-mirror System with Zernike Surface

摘要

This paper presents a new idea that designing a high speed telescope system with freeform surface. The system is designed based on the relation that between the coefficient of Zernike polynomial and Seidel aberration, so that we can control the aberrations of every field of view and alternation optimize with a specific aim. The primary mirror is freeform surface, and others are conicoid. It is telecentric in the image space. Its F-number is 2.0, its focal length 360mm, and its field of view 4 degrees. This system is compact and diffraction-limited. It's unique in that the chief ray on the 0 field of view traces along the line between every vertex of elements, so that its assembly difficulty is greatly reduced, the working distance is long and good to place the color filters.