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

• DOI: 10.1007/s11801-008-7133-4
• Publication Date: 2008-04-22T07:34:33Z
• Authors: Ju-an Ruan; Qing-ke Zeng; Zi-xiong Qin; Wei-yuan Liang; Ping Huang
• Keywords: Cladding (metalworking); Temperature coefficient; Cladding mode; Long-period fiber grating

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/°C and a temperature resolution less than 0.1 °C are obtained.