A Novel Temperature-Insensitive Fiber Bragg Grating Sensor for Pressure Measurement

This paper presents the design and development of an optical fiber Bragg grating (FBG) based pressure sensor. A FBG is glued onto the surface of a specially designed cantilever beam. Under external pressure, the reflection spectrum of the FBG split into a double-peak structure. It is found that the gap between the two peaks of the reflection spectrum changes linearly with the variation of the pressure at the free end of the beam. Pressure sensing is realized by measuring the gap between the double-peak using an optical spectrum analyzer (OSA). A linear response of 0.57 N/nm was obtained within a pressure range of 1 to 3N. This sensor is temperature independent due to the temperature independent nature of the double-peak structure of the reflection spectrum.