Fabrication of a micromachined optical modulator using the CMOSprocess

Abstract

This paper presents a new micromachined optical modulator designwith electrostatic actuation fabricated by the conventional complementarymetal-oxide semiconductor (CMOS) process. The modulator is operated bythe interaction of the fixed part, stationary gratings and the movablepart, sliding gratings. The period of the gratings varies with the slideof the movable part, thereby allowing different diffraction patterns ofthe reflected light. In addition, 100% modulation in the first order canserve as an optical switch. All procedures following the CMOS processmerely require a simple post-process with maskless etching. Withdifferent profiles of the shape and sacrificial layer, two types ofmodulator are developed to obtain a high-aspect ratio and high efficiencyof modulation, respectively.