Optical fiber temperature sensor based on bimetallic and FP interference structure
In order to improve the sensitivity and temperature measurement range of existing optical fiber temperature sensors,a light-transmission type optical fiber temperature sensor based on bimetallic and Fabry-Perot (FP)interference structure is proposed. A bimetallic strip is used as the temperature sensing element,and a partial mirror and a bimetallic strip are used as the upper and lower surfaces to form the FP cavity. The frequency modulation laser interference principle is used to measure the length variation of FP cavity generated by the heat of the temperature sensing element,so as to realize temperature sensing. The experimental results show that the cavity length variation of the optical fiber temperature sensor has a good linear relationship with the temperature,the linearity is 99. 96%,the temperature measurement sensitivity reaches 3885 nm/℃,and the repeatability is high.
fibre-optic temperature sensorbimetallic stripFabry-Perot(FP)interference cavity