A single-fringe etalon silicon pressure transducer

This paper describes the development of an interferometric pressure transducer using a single etalon fringe as an intensity mode signal for a deflectable silicon diagram. The last fringe before the mechanical contact of the two etalon surfaces is employed, thus, providing an integral overpressure limit. The etalon design permits the illumination source to be only approximately monochromatic thereby allowing a conventional LED to be used in place of the laser diode normally required in interferometric designs and greatly simplifies the pressure sensor and instrumentation package.