Thermally actuated free-form MEMS mirrors

Abstract

Quasi-non-diffracting beams are used in a wide range of applications because of their ability to localize the radiation energy in narrow spatial and angular distributions. We present the development of free-form tunable MEMS mirrors to generate non-diffracting beams with unique spatial profiles. The mirror surface defined by a polynomial function is produced by shape optimization of a mold for subsequent molding profiting explicitly from a well-defined volume shrinkage. The actuation is achieved by thermal expansion of a polymer layer, which defines the final tuned shape of the mirror. The deflection of the mirror surface and the resulting iry beam is characterized.