Comparison of single and double cladding long period fiber grating sensor using an intensity modulation interrogation system

The performance of long period fiber grating (LPFG) sensors written in single cladding and double cladding fibers have been compared by using a fast responding interrogation system based on intensity modulation. Temperature and dynamic strain monitoring using this system have been demonstrated. This system is capable of resolving strain to 0.2 and 0.4 με at a loading frequency of 20 Hz, and temperature resolution to 0.02 and 0.19 °C by using LPFG in the single cladding (SC-LPFG) and double cladding (DC-LPFG), respectively.