CO₂ laser-grooved long period fiber grating temperature sensor system based on intensity modulation

Abstract

A long period fiber grating (LPFG) temperature sensor system based on intensity modulation is developed. The LPFG employed is fabricated by the use of a focused CO₂ laser beam to carve periodic grooves on the fiber. The temperature measurement resolution of up to 0.1°C has been obtained within the temperature range between 20°C and 100°C. The system uses a simple intensity measurement method and exhibits the advantages of convenient intensity measurement, double temperature sensitivity, high resolution, simple configuration, and low cost.