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

Raman spectroscopy was performed on the cores of germanosilicate optical 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 reactions occur in these two cases. Thermally initiated reactions resulted in GeH and SiOH production. Ultraviolet-light-initiated reactions produced species characteristic of a local reaction occurring at the oxygen deficient 'GeO' defect. In this latter case, the reaction product was determined to be GeH2, with the notable absence of both SiOH and GeOH.