Abstract

All-reflective systems have been applied to optical systems because of less material limitations compared with refractive systems. The key to designing an all-reflective system is how to widen the field view and the aperture without obstruction by mirrors. In order to avoid the obstruction, several systems have been designed to work off-axis with respect to the field angle, which show rotational asymmetry around the optical axis. In this paper, we propose a design method adapted effectively to this asymmetry by use of anamorphic mirrors and an elliptic aperture. In our method two main design factors, placement of mirrors and enlargement of the aperture, are separately optimized. We show a design example of a three-mirror system reaching an F-number of 1.2 with 18×14 degrees field angle.

© 2002 Optical Society of America