Ultraviolet absorption studies of germanium silicate glasses.

TLDR: The absorptions of pure and codoped germanium silicate preforms made by modified chemical vapor deposition (MCVD) have been studied from 170 to 400 nm, and the GeO content is found to increase with processing temperature, because higher temperature allows the greater dissociation of GeO(2) to GeO.

Abstract: The absorptions of pure and codoped germanium silicate preforms made by modified chemical vapor deposition (MCVD) have been studied from 170 to 400 nm. Three bands with maxima at 185, 242, and 325 nm have been observed. The shortest wavelength band is attributed to GeO2, while the other bands are assigned to GeO. The 242- and 325-nm bands are correlated with a singlet–singlet and a triplet–singlet transition of GeO, respectively. The GeO content is found to increase with processing temperature, because higher temperature allows the greater dissociation of GeO2 to GeO. The amount of GeO incorporated is determined to be of the order of 10−2 wt. %. The 325-nm band of GeO should have no effect on fiber loss in the IR region.