Fibre bragg gratings as high dose radiation sensors?

We have measured for the first time the shift of the Bragg wavelength and other parameters of fibre Bragg gratings (FBGs) exposed to ?-radiation up to a dose of 100 kGy at different wavelengths. The results show that the FBG sensitivity to radiation increases from 657 nm to 1516 nm so that FBGs with higher Bragg wavelength, e.g. 1.55 µm, are good candidates for high dose radiation sensing: no saturation was observed up to 100 kGy and the measured wavelength shift of one of the investigated FBGs was fairly independent of the radiation dose rate.