Polarization-Insensitive Discrimination of Strain and Temperature Based on Long-Period Fiber Grating Inscribed on High-Birefringent Fiber Ended with Faraday Rotator Mirror

A new fiber-optic-sensing scheme capable of performing a simultaneous measurement of strain and temperature has been developed using a long-period fiber grating (LPG) inscribed on a high-birefringent fiber (HBF), which is ended with a Faraday rotator mirror (FRM). By incorporating the FRM following the LPG inscribed on the HBF (HB-LPG), the number of spectral scans can be reduced to only one and the potential drawbacks due to the use of the polarized light source can also be completely removed, as compared with a previous system based on a single HB-LPG.