Examine the design of the micro torsion mirror using holographic and stroboscopic interferometries

Abstract

In this paper, the theoretical models of resonant frequencies related to the first torsion mode and the second bending mode of the micro torsion mirror are derived. The design and fabrication of the micro torsion mirror device are also purposed. In the analysis of design of the micro device, the advanced design package COMSOL is used to multi-investigate the processes of fabrication. Resonant frequencies and related modes can also be simulated. The fabrication process includes bulk and surface micromachining, and the rich experiences of using dry and wet etching. The resonant frequencies of the fabricated device can be measured by using a laser Doppler interferometer. Torsion and bending inteferograms and full-field modes can be constructed by using holographic and stroboscopic interferometries when the device is excited at the resonant frequencies. Resonant frequencies obtained by using methods of theory, simulation, holographic interferometries, stroboscopic interferometries, and a laser Doppler interferometer are shown.