Photoluminescence of Bragg gratings in germanosilicate fibres excited at 488 nm

The authors have observed photoluminescence peaked near 667 nm from Bragg gratings written in germanosilicate fibres upon excitation by 488nm radiation. The observed luminescence spectrum is consistent with the 1.9eV spectrum owing. to nonbridging oxygen hole centres in silica and germanium doped silica glasses. The strength of the luminescence appears to vary significantly depending on the fibre composition, but did not depend strongly on hydrogen content in one type of fibre studied.