The study of enhancing temperature sensitivity for FBG temperature sensor

Abstract

In this paper, the basic sensing principle of fiber bragg grating(FBG) temperature sensor is introduced, and the general packaging methods are showed. On that basis, a new method of packaging FBG is advanced, which increases the thermal sensitivity coefficient and eliminates the impact of stress. Through experiments, the thermal characteristics and stress effect of the naked FBG and the packaged FBG are analyzed, the results show that the trend line of the packaged FBG has good linearity, and the method basically eliminates the stress effect, the sensor can be used accurately to monitor states of the thermal equipments, and the thermal range sensed is from -15℃ to 200℃.

Recent advances in optical fiber high-temperature sensors and encapsulation technique [Invited]

“…To improve the temperature range of the sensor, their team [120] subsequently bonded surface relief fiber Bragg gratings (SR-FBGs) to a metal substrate in 2006 and successfully achieved a high-temperature linear response up to 800°C. In 2009, Li et al [121] bonded a steel tube encapsulated FBG to a semi-cylindrical metal sheet to enhance temperature sensitivity and eliminate the effect of stress. The average temperature sensitivity in the range of −15°C to 200°C reached 18.64 pm/°C.…”