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 grati ng Fabry-Perot cavity (GFPC) structure was fabricated and tested for simult aneous measurement of strain and temperature. The sensor exhibits unique pr operties that it possesses two spectral peaks within its main reflection ba nd and the normalized peak power difference, in addition to its peak wavele ngth shift, changes linearly with strain or temperature. The accuracy of th is particular sensor in measuring strain and temperature are estimated to b e +/- 30 mu epsilon in a range from 0 to 3000 mu epsilon and +/-0.4 degrees C from 20 degrees C to 60 degrees C, respectively.