Three-leaf trefoil-type MEMS tunable corner cube retro-reflector

摘要

A three-leaf trefoil-type corner cube retro-reflector (CCR) fabricated by the MUMPs polysilicon surface micromachining process is presented. Unlike most of other MEMS CCRs, our CCR''s opening faces straight upwards, making its (1, 1, 1) direction, i.e. the direction along which the retro-reflection efficiency is maximum, perpendicular to the surface of the substrate. This architecture is more suitable for applications such as CCR-based portable, dynamic, optical identification cards. The tunability can be achieved by employing an electrostatically-actuated gap-closing mirror (0.4° tilt at 250 V) as one of the three CCR reflecting ‘leaves’.