Micro machined diaphragm based fiber Fabry-Perot acoustic sensor

Abstract

This paper presents the design and characterization of the micro machined Diaphragm and the Fabry-Perot interferometer of the fiber Fabry-Perot acoustic sensor. The design for micro diaphragm-type acoustic sensors have been established by characterization of the relationships among diaphragm thickness, side length, sensitivity, and resonant frequency. According to the study, the thickness need to be thin and the side length need to be small in order to get the sensitive diaphragm with high resonant frequency. Theoretical equations for the sensitivity, visibility are proposed. The relations between the reflectivities of the F-P surfaces and the visibility are discussed. Design of different cavity lengths and reflectivities are proposed for the diaphragm-based micro machined optic F-P sensors which have the visibility up to 100%. © 2011 Springer-Verlag.