Feedback controlled single wavelength interrogation technique for miniature all-silica EFPI fibre optic pressure sensors

Abstract

This paper proposes a novel technique to stabilise the output wavelength of a tuneable laser source to operate always in the linear range of a miniature all-silica Extrinsic Fabry-Perot Interferometric (EFPI) fibre optic pressure sensor. The technique is based on a fibre optic hybrid sensor, which consists of a miniature all-silica EFPI fibre optic pressure sensor with an incorporated in-Fibre Bragg Grating (FBG). The FBG temperature reference sensor is used as a feedback element to stabilise the output wavelength of a tuneable laser source. Therefore the novel interrogation technique allows high speed pressure measurements in high temperature environments.