Radiation-Resistant Optical Fiber Fabry-Perot Interferometer Used for High-Temperature Sensing

An optical fiber Fabry-Perot interferometer based on sapphire wafer is designed and fabricated for high-temperature sensing under Co-60 γ irradiation. The sensing probe is composed by a thin sapphire wafer and a pure silica multi-mode fiber. In the experiment, the interferometer is exposed under the Co-60 γ irradiation with different irradiation time and absorbed dose rate. The irradiated optical fiber sensor underwent three temperature cycle tests up to 800°C and demonstrated excellent sensing performance at high temperature. The whole sensing system has the capability to survive in high temperature environment that surpasses 800°C. The interferometer can achieve the high sensitivity of 29.9 pm/°C at the wavelength around 1340 nm when the temperature is 800°C. The proposed sensor and sensing system has great potential to be applied under strong irradiation and high temperature.