THERMAL AND PHOTO-INITIATED REACTIONS OF H-2 WITH GERMANOSILICATE OPTICAL FIBERS

Raman spectroscopy was performed on the cores of germanosilicate optic al fibers into which molecular hydrogen was diffused and subsequently treated with either heat or low-intensity ultraviolet light at 254 nm. The results indicate that distinctly different hydrogen addition reac tions occur in these two cases. Thermally initiated reactions resulted in GeH and SiOH production. Ultraviolet-light-initiated reactions pro duced species characteristic of a local reaction occurring at the oxyg en deficient 'GeO' defect. In this latter case, the reaction product w as determined to be GeH2, with the notable absence of both SiOH and Ge OH.