Micro-mechanical modulator having an improved membrane configuration

摘要

An optical modulator that contains a flexible dielectric membrane suspended over a substrate. The flexible membrane is made of a dielectric material such as silicon nitride. In one embodiment of the invention, the flexible membrane has an optically active region. A contact region is maintained in the vicinity of the optically active region which is electrically isolated therefrom. The contact region which includes a conductive material draws accumulated charge build-up from the optically active region. In another embodiment a first area of conductive material is formed on at least one surface of the flexible membrane proximate its center. At least one second area of conductive material is formed on at least one surface of the flexible membrane surrounding the first area. The first area of conductive material is kept electrically isolated from the surrounding second area. The first area of conductive material is coupled to an electrical ground. When an electrical potential is applied between the flexible membrane and the below-lying substrate, only the second areas of conductive material are affected. As a result, only the second areas of conductive material act to deform the membrane. The first area of conductive material in the center of the membrane remains unaffected and ensures that the membrane deforms in a uniform manner.