Piezoelectric Deformable MEMS Mirror for Adaptive Optics Composed of PZT Thin Films

In this paper we present the piezoelectric-driven deformable mirror for adaptive optics (AO). The deformable mirror, which is used to correct the disturbed wave front, is composed of a piezoelectric PZT film deposited on a SOI substrate. The mirror membrane of 15 mm in diameter was fabricated by etching the handle wafer, while the exposed oxide layer was coated by Al layer as a mirror surface. The individual Al electrodes were deposited on the PZT film to accomplish 19 PZT/Si unimorph actuator array. The dynamic deformation of the mirror was measured by a laser Doppler vibrometer and the large displacement more than 5 mum was obtained by the application of low voltage of 10 V. The deformation of the mirror according to Zernike´s polynomials was examined and mirror surface to 3^rd order Zernike modes could be generated