Fiber Bragg grating cavity sensor for simultaneous measurement of strain and temperature

A novel and short (5 mm long) fiber grating based sensor with a fiber grating Fabry-Perot cavity (GFPC) structure was fabricated and tested for simultaneous measurement of strain and temperature. The sensor exhibits unique properties that it possesses two spectral peaks within its main reflection band and the normalized peak power difference, in addition to its peak wavelength shift, changes linearly with strain or temperature. The accuracy of this particular sensor in measuring strain and temperature are estimated to be /spl plusmn/30 μs in a range from 0 to 3000 μs and /spl plusmn/0.4/spl deg/C from 20/spl deg/C to 60/spl deg/C, respectively.