Abstract

In this paper, we analyzed the temperature sensitivity of long-period fiber gratings (LPFG) using the coupled modes theory. The results show that the temperature-sensitivity of LPFG depends not only on the fiber core characteristics and grating period, but also on the cladding characteristics. By selecting the fiber parameters, we can design temperature-sensitive or temperature-insensitive LPFG sensors. We mainly studied temperature-sensitive LPFG in the temperature range of 25°C~105°C. The experimental result shows that the LPFG’s temperature sensitivity is 0.086nm/°C, which is about 8.3 times the typical value of normal fiber Bragg grating. The temperature response curve of LPFG corresponded with the theoretical curve and had good linearity.

© 2005 Optical Society of America