Fiber optic extrinsic Fabry-Perot interferometric sensor for high blast pressure measurement

Abstract

Optical fiber based Extrinsic Fabry-Perot Interferometric (EFPI) sensor significantly emerged as an advanced optical sensor for the health monitoring of civil, mechanical and aeronautical structures. This sensor responds its well capability also towards the measurement of acoustic/shock wave pressure. This paper presents an approach for high blast (acoustic/shock wave) pressure measurement using low cost indigenous rugged type optical fiber EFPI sensor. Optical fiber EFPI sensor works on the two fundamental principles; Fresnel reflection and Fabry-Perot Interferometry by interconnecting single mode optical fiber within the silica capillary which represents Fabry-Perot cavity (or air cavity) as sensing elements. This sensor consists of dielectric materials and is immune to Electromagnetic Interference (EMI), Radio Frequency Interference (RFI) and less sensitive to noise. This paper highlights the fabrication as well as packaging techniques of EFPI sensor which are experimentally more reliable in blast pressure.