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 gamma 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 gamma irradiation with different irradiation time and absorbed dose rate. The irradiated optical fiber sensor underwent three temperature cycle tests up to 800 degrees 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 degrees C. The interferometer can achieve the high sensitivity of 29.9 pm/degrees C at the wavelength around 1340 nm when the temperature is 800 degrees C. The proposed sensor and sensing system has great potential to be applied under strong irradiation and high temperature.