Intrinsic Fabry-Pérot interferometric (IFPI) fiber pressure sensor

An optical fiber Single/Multi-/Single-mode Intrinsic Fabry-Pérot Interferometer (SMS-IFPI) pressure sensor has been demonstrated using a silica tube-based pressure transducer hermetically sealed by thermal fusion bonding. The sensor, made entirely of fused silica, contains an IFPI strain sensor enclosed by a CO2 laser-bonded outer tube. A sensor prototype is constructed and demonstrated for single point pressure sensing at high temperature (600°C), with temperature compensation achieved through co-location of an SMS-IFPI temperature sensor. The inline geometry and low transmission loss of the SMS-IFPI sensor makes it suitable for frequency division multiplexing (FDM) in a single fiber branch. In future work, we envision multiplexing of up to eight such IFPI pressure sensors along a single fiber branch for quasi-distributed pressure measurement.