Research On Temperature Sensing Characteristics Of PbS Fiber Based On Temperature Sensitive Birefringence Effect

In recent years,temperature sensors have been widely used in power systems,aerospace,marine development and other fields.The optical fiber temperature sensor has many advantages,such as radiation resistance,small size,light weight,and high sensitivity.Because of the advantages of fast response,it can be used in harsh environments with flammable,explosive,space-limited and strong electromagnetic interference.Therefore,a PbS fiber optic temperature sensor based on temperature-sensitive birefringence effect has been proposed.In this paper,the temperature-sensitive characteristics of PbS optical fiber temperature sensor with different structures are analyzed based on the domestic and foreign research status of different types of optical fiber temperature sensors.And the theoretical simulation and experimental verification are carried out.The main contents are included as follows.Firstly,the polarization controller,optical fiber coupler,and Jones matrix of PbS fiber are introduced.The transmission function of first-order PbS fiber Sagnac interferometer,the second-order PbS fiber Solc-Sagnac interferometer and the second-order PbS fiber Loyt-Sagnac are analyzed by Jones matrix theory.Secondly,the preparation process of PbS fiber sensor is studied.The temperature and stress sensing characteristics of first-order PbS fiber Sagnac interferometer are analyzed.The relationship between different temperature,stress,and wavelength shift is studied experimentally.Thirdly,the temperature sensing characteristics of second-order PbS optical fiber Solc-Sagnac interferometer are studied.The influence of different length of the PbS fiber on the spectrum are analyzed.The relationship between temperature and wavelength shift is established experimentally.Finally,the temperature sensing characteristics of second-order PbS fiber Loyt-Sagnac interferometer are studied.The influence of different lengths of PbS fiber on the spectrum is analyzed.The relationship between temperature and wavelength shiftis established experimentally.