A bulk-micromachined corner cube retroreflector with piezoelectric micro-cantilevers

Abstract

A piezoelectrically actuated corner cube retroreflector (CCR) has been investigated for free space optical communications. The proposed CCR consisted of two mutually orthogonal bulk-micromachined mirror assembled with piezoelectrically actuated horizontal mirror. The vertical mirrors were fabricated by using anisotropic wet-etching of double silicon-on-insulator (SOI) wafer and horizontal mirror was supported by two stress-compensating and one actuating lead zirconate titanate (PZT) micro-cantilevers. The fabricated CCRs exhibited angular displacement of 1.87° at 5 volts and switching times of 276 µ s. It also exhibited a good cut-off frequency of 2.5 kHz which can be digitally modulated up to about 5 kb/s.