Inscription of fibre Bragg gratings in non-sensitised fibres using VUV F2 laser radiation

We report the inscription of fibre Bragg gratings in non-sensitised SMF 28 and HI 980 fibre by exposure to VUV F2 laser radiation at 157nm. The modulated effective refractive index change Δneff deduced from the shift in the grating reflection peaks was Δneff=2.8×10-4 and 1.7×10-4 in SMF 28 and HI 980 fibre respectively. The possible influence of non-uniformity of core exposure and VUV cladding absorption loss on these results is discussed.