Integrated optic pressure sensor on silicon substrate

A novel integrated optic pressure sensor was constructed with the Mach-Zehnder interferometer structure of glass waveguides on a silicon substrate. Pressure is sensed by detecting the deformation of a thin diaphragm fabricated by using the anisotropic etching of a silicon substrate. The basic design concept of the present sensor was provided by analyzing its operation. The measurable pressure range and the sensitivity can be set by the proper selection of the diaphragm structure. A device was built and its operation performances were tested at 633 nm. For the fabricated device, the measured halfwave pressure was 0.8 x 10(5) Pa and the extinction ratio was 10 dB.