Research on a fiber Bragg grating temperature measurement method for inter-satellite laser link

In this paper, a fiber Bragg grating (FBG) temperature measurement method for intersatellite laser link is studied. Based on the analysis of the FBG temperature measurement method, the FBG sensing demodulation system is built to calibrate its wavelength and temperature parameters. The experimental data of temperature gradient monitoring are compared with the on-orbit real-time temperature data of a satellite's solar array measured by the thermistor to verify the temperature monitoring accuracy and stability of the FBG sensing demodulation system. The FBG sensing demodulation system and the thermistor temperature measurement system are compared under the same environmental conditions during the constant temperature period, the continuous heating phase and the natural cooling phase. The results show that during the constant temperature period, the temperature fluctuation range and standard deviation of the FBG sensing demodulation system are ±0.16 °C and 0.08 °C, respectively, which is significantly better than the performance of the thermistor temperature measurement system, whose temperature fluctuation range and standard deviation are ±5.92 °C and 1.08 °C, respectively. The temperature response speed of the former is significantly faster than that of the latter during the continuous heating phase and the natural cooling phase.