三葉草型微機電可調變Corner Cube Retro-reflector (CCR)光學回射器

Abstract

本論文擬以Corner Cube Retro-reflector (CCR)來設計一光學回射器元件。藉由調變反射面鏡來破壞回射之條件，以此作為訊號調變器，可以用來傳送圖形或文字，產生動態之圖像。利用傳遞的光資訊可以同時擁有時間上及空間上的編碼(即動態之金鑰圖案)，如此便可建構具備高隱密性、高安全性的光學式的身分識別系統(Optical ID)。

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’.