Stabilization of Fiber Bragg Gratings Against Gamma Radiation

The effect of gamma-radiation on the spectral characteristics of FBGs has been studied experimentally. The FBGs were fabricated in optical fibers with a GeO
₂
concentration in the core in a range from several to 99 mol.%. Various pre- and post-fabrication treatments were applied with the aim to improve the radiation tolerance of the FBGs. The best result was obtained for a Type IIa annealed grating written in SM310 fiber, where the Bragg peak shift saturated at a 12 pm level and an amplitude change of 0.04 dB with the maximal dose of about 50 kGy.