Miniature fiber optic pressure and temperature sensors

Abstract

New miniature extrinsic Fabry-Perot interferometric (MEFPI) optical fiber sensors with a size of 125μm in diameter are presented, which are ideal for applications where the operation space is highly restricted. The temperature sensor can work up to 800°C with a sensitivity of 0.46nm/°C. The pressure sensor exhibited a sensitivity of about 0.36nm/psi. The sensitivities of the pressure and temperature sensor can be controlled with high precision during fabrication. In addition, their Fabry-Perot cavity lengths can be controlled with a resolution of several nanometers, which provides excellent flexibility in sensor design and signal demodulation. The sensors are composed entirely of fused silica, which is very reliable, biocompatible, corrosion resistant and immune to electromagnetic interference (EMI).