Theoretical compensation of static deformations of freeform multi mirror substrates

Abstract

Varying temperatures influence the figure errors of freeform metal mirrors by thermal expansion. Furthermore, different materials lead to thermo-elastic bending effects. The article presents a derivation of a compensation approach for general static loads. Utilizing perturbation theory this approach works for shape compensation of substrates which operate in various temperature environments. Verification is made using a finite element analysis which is further used to produce manufacturable CAD models. The remaining low spatial frequency errors are deterministically correctable using diamond turning or polishing techniques. (120.4880) Optomechanics, (120.6810) Thermal effects, (260.3910) Metal optics, (120.4610) Optical fabrication, (220.1920) Diamond machining