Fig. 1. Thermal expansion coefficient and thermo-optical coefficient of materials in cryogenic environment versus temperature. (a) Thermal expansion coefficient of Spectrosil 1000 quartz; (b) thermo-optical coefficient of quartz

Fig. 2. Structural diagram of optical fiber temperature/strain demodulation system

Fig. 3. Schematic of optical fiber temperature sensor

Fig. 4. Schematic of optical fiber strain sensor

Fig. 5. High temperature and cryogenic experimental platform for optical fiber temperature/strain sensing system

Fig. 6. Central wavelength change of temperature sensor within -252.75--200.94 ℃

Fig. 7. Strain value change demodulated by strain sensor after high temperature and cryogenic test

Fig. 8. Measured value stability of temperature sensor at each temperature node

Fig. 9. Architecture diagram of optical fiber mechanical and thermal multiparameter sensing instrument

Fig. 10. Picture of optical fiber mechanical and thermal multiparameter sensing instrument

Fig. 11. Interface design of optical fiber mechanical and thermal multiparameter sensing instrument