Zernike generation with a non-contact, thermally actuated deformable mirror

Abstract

Wavefront aberrations are commonly expressed in a series of orthogonal Zernike polynomial terms [1]. Each of these Zernike polynomials mathematically describes a certain typical deviation from an ideal wavefront. To correct for optical aberrations a deformable mirror must be able to actuate the shapes corresponding to these terms. This paper presents the results of experiments to actuate a deformable mirror surface, using a non-contact thermal actuation principle. Thermal radiation induces a temperature distribution on the mirror substrate which causes mirror surface deformation. In the experiments, shapes are actuated up to Z3³ with amplitudes ~ 60 [nm] and ~ 3 [nm] root mean square (RMS) shape error.