Design of freeform nonsymmetric three-mirror systems using Gaussian radial basis functions freeform surfaces

Abstract

As a kind of radial basis functions, the Gaussian function has local feature and therefore has an excellent surface description ability. In this paper, we proposed the design strategy of freeform unobscured three-mirror system using Gaussian radial basis functions surface type and demonstrate a design example. A novel and high-accuracy surface fitting algorithm of Gaussian radial basis functions is proposed for the freeform surface fitting. Successive optimization strategy is employed for the system after surface fitting. The final example system works at the long wave infrared band and has an 8°×6° field-of-view with an F-number of 1.9.