High-sensitivity temperature sensor based on long-period fiber grating

Abstract:

Temperature sensitivity is greatly improved by taking the following three measures:proper long-period fiber grating(LPFG) whose strain coefficient of the core is larger than that of the cladding is employed.the LPFG is coated with a thin film of the material whose refractive index decreases with the temperature.and the sensor is encapsulated by metal material whose thermal expansion coefficient is large.By computer simulation,a measured temperature coefficient of 0.2375 nm/℃ and a temperature resolution less than 0.1 ℃ are obtained.