A MINIATURE FABRY-PEROT-INTERFEROMETER WITH A CORRUGATED SILICON DIAPHRAGM SUPPORT

The techniques of silicon micromachining have been used to fabricate a second-generation Fabry-Perot interferometer for use in the near infrared spectral region. Two silicon wafers, one with movable central elements, with deposited highly reflective dielectric mirrors are bonded together leaving a small gap between the mirrors, and sawn into individual devices. These devices provide a sharp optical transmission peak which can be used as a wavelength division demultiplexer in optical fiber communications systems or as a very sensitive sensor of the gap between the mirrors. The wavelength tuning and parallelism control of the mirror elements are achieved electrostatically, by varying the voltage between control electrodes. This second-generation device includes a thin etch-stopped corrugated diaphragm as the suspension for the movable element, which allows increases travel in a chip only 5 mm square.