Comparing the properties of various sensitization methods in H2-loaded, UV hypersensitized or OH-flooded standard germanosilicate fibers

The properties of three sensitization processes: UV hypersensitization, OH- flooding and H-2- loading have been investigated through Bragg grating ( BG) inscription within standard germanosilicate fibers. More specifically, the stability of the sensitization processes and that of the UV- induced index changes have been investigated through isochronal annealing experiments. Moreover, the level of excess loss induced near 1.4 mu m by both the sensitization process and the BG inscription has been estimated by means of in fiber absorption spectroscopy. The level of loss proves to be higher in the hypersensitized or OH- flooded fiber than in the H-2- loaded counterpart when pulsed 248 nm light was used. (C) 2005 Optical Society of America.