Hi,
You may have a look at:
1- “Thermal dependence of the strain response of optical fibre Bragg gratings”, https://doi.org/10.1088/0957-0233/15/8/031
2- E. Filho, M. Baiad, M. Gagné, and R. Kashyap, “Fiber Bragg gratings for low-temperature measurement,” Opt. Express 22, 27681-27694 (2014).
3- A. Donko, M. Nuñez-Velazquez, P. Barua, F. Cruz, R. Ismaeel, T. Lee, J. Sahu, M. Beresna, and G. Brambilla, “Femtosecond inscription and thermal testing of Bragg gratings in high concentration (40 mol%) germania-doped optical fibre,” Opt. Express 25, 32879-32886 (2017).
4- General Reference: Handbook of Optical Constants of Solids by Palik
Kind Regards,
Amin