An interferometric spatial light modulator comprises of two cavities. One is the optical resonant cavity having a partially reflective film and a movable reflective membrane as two walls, and the other is the electromechanical actuation cavity having the movable reflective membrane and a bottom metal...http://www.google.com/patents/US7629197?utm_source=gb-gplus-sharePatent US7629197 - Spatial light modulator
