Optical design of three-mirror telescope system

A configuration called three-mirror anastigmat (TMA) system, which is coaxial system used in off-axis situation, is discussed. TMA is made up of three conic mirrors, a deform mirror and a fast steering mirror. The initial configuration is obtained according to the theory of the first order aberrations, and then optimizes with the software of automation optical design Zemax. The exit pupil can be located at the deform mirror to correct the residual aberrations caused by the primary mirror. Two methods are applied to meet this requirement. The image quality of the optical system designed is near the diffraction-limited, and can satisfy the requirement of the usage.