Active microinterferometer with liquid crystal on silicon (LCOS) for extended range static and dynamic micromembrane measurement

摘要

Increasing technological capabilities to produce active microelements (incl. microbeams, micromembranes and micromirrors) and their expanding areas of application introduce unprecedented requirements concerning their design and testing. Conventional two beam interferometry is one of the most popular testing method of microelements that have reflecting surface. Sometimes elements under test have complicated shape or shape gradients which restricts their testing by means of interferometer with flat reference mirror. In this paper we propose to use Liquid Crystal On Silicon (LCOS) spatial light modulator which serves as an adaptive reference mirror and phase shifter in Twyman-Green interferometer applied for microelements measurement. Initial tests have been performed and results confirming applicability of LCOS in active interferometer system are presented.