FBG sensor interrogation with high temperature insensitivity by using a HiBi-PCF Sagnac loop filter

We propose and demonstrate a temperature insensitive fiber Bragg grating (FBG) sensor interrogation system that uses a highly birefringent photonic crystal fiber (HiBi-PCF) Sagnac loop filter. Because of the high birefringence and the low temperature sensitivity of the HiBi-PCF, the loop fiber length is greatly reduced and the temperature stability of the system is dramatically improved. Experiment has been carried out by interrogating a FBG with applied strain. Good performances have been obtained.