Experimental studies were made of the luminescence spectra, excited at 488nm, of H-loaded germanosilicate optical fibres which had been annealed in air at temperatures of up to 500C. Two types of Ge-H defect were identified by their emission bands at 650 or 740nm. The precursors of the former were drawing-induced GeE' defects, while the latter were due to the reaction of H molecules at the Ge-O-Si site. Another band, which was centered at 390nm, was also observed in high-temperature treated fibres. It was suggested to be due to Ge lone-pair centre luminescence.

Luminescence Spectroscopy of Hydrogen-Associated Defects in Hydrogen-Loaded and Heated Germanosilicate Optical Fibres. F.Goutaland, H.Kuswanto, A.Yahya, A.Boukenter, Y.Ouerdane: Philosophical Magazine B, 1999, 79[11-12], 2137-43