Simultaneous measurement of strain and temperature incorporating a long-period fiber grating inscribed on a polarization-maintaining fiber

Simultaneous measurement of strain and temperature was demonstrated by using a long-period fiber grating inscribed on a polarization-maintaining fiber (PM-LPG). The spectral sensitivities of the two adjacent resonant dips of the PM-LPG were measured with respect to strain and temperature. The sensitivities of each resonant dip for strain and temperature were different in magnitude and sign, which makes this PM-LPG have a capability of simultaneously sensing strain and temperature. Experimental results show root mean square deviations of 15.6 muepsilon and 0.7 degreesC for strain and temperature, respectively.