Hybrid LPFG/MEFPI sensor for simultaneous measurement of high-temperature and strain.

A hybrid fiber-optic sensor consisting of a long-period fiber grating (LPFG) and a micro extrinsic Fabry-Perot (F-P) interferometric (MEFPI) sensor is proposed and demonstrated for simultaneous measurement of high-temperature and strain. The LPFG written by using high-frequency CO(3+) laser pulses is used for high-temperature measurement while the MEFPI sensor fabricated by using 157nm F(2) laser pulses is used for strain measurement under high temperature. The distinguishing feature of such a hybrid fiber-optic sensor is that it can stand for high temperature of up to 650 masculineC and achieve precise measurement of strain under high temperature conditions simultaneously.