γ-Ray irradiation effect on transmission loss for ZrF4− based optical fibres

The y-ray irradiation effect on the transmission loss of ZrF4-BAF2-GdF3-AlF3 and ZrF4-BaF2-GdF3-AlF3-PbF2 optical fibres is investigated. Absorption bands are induced in the ultraviolet to near infrared region, and their tails increase the transmission losses in the mid-infrared region. Induced transmission losses for a dose of 106 R are 1000-2300 dB/km in the 2-4 μm band. These values are comparable to those at 1.5 μm for doped silica fibres.