A lateral pressure sensor using a fiber Bragg grating

This study develops an all-optical high-sensitivity pressure sensor based on fiber Bragg grating (FBG) encapsulated in a polymer-half-filled metal cylinder. The polymer can be pressurized along one radial direction only, and responds to an axial force on the round plate, creating an axial stretched-strain on the FBG. The measured pressure sensitivity is 2.2/spl times/10/sup -2/ MPa/sup -1/, which is 10 900 times higher than for a bare FBG. Owing to its good linearity, this sensor can be applied to measure medium pressure, liquid level, and depth underwater.