Low Temperature Characteristics of FBG Temperature Sensors with Small-size Packaging

摘要

Two small-size package methods, thin stainless steel tube based package method and plating gold based package method for fiber Bragg grating (FBG) temperature sensors, are designed. The characteristics of the FBG temperature sensors in the environment temperature between 203 K and 243 K are investigated. The wavelengths of the FBG temperature sensors as a function of the temperature are examined experimentally. The experiment results of the two different small-size package sensors in identical conditions are compared with each other. The transmission spectrum of the sensors is analyzed at the temperature of 273 K and 213 K. The temperature sensitive factors of the sensors are derived analytically and are verified by experiments. Linear fitting to the wavelength-temperature curve is carried out.