The thermal stability of fibre Bragg gratings written in hydrogen-loaded standard telecommunication fibres can be significantly enhanced by pre-irradiating the fibre with UV beam before writing gratings. Our experimental result shows that these gratings maintained more than 60% of their initial index modulation after 10 hours at 605°C.
Bai-Ou Guan, Bai-Ou Guan,
"Fibre Bragg gratings with high thermal stability", Proc. SPIE 4185, Fourteenth International Conference on Optical Fiber Sensors, 418536 (9 November 2000); doi: 10.1117/12.2302257; https://doi.org/10.1117/12.2302257