Em. Dianov et al., OPTICAL-ABSORPTION AND LUMINESCENCE OF GERMANIUM OXYGEN-DEFICIENT CENTERS IN DENSIFIED GERMANOSILICATE GLASS, Optics letters, 22(14), 1997, pp. 1089-1091
Spectroscopic properties of germanium oxygen-deficient centers were st
udied in vapor axial deposition and modified chemical-vapor deposition
germanosilicate glass after hydrostatic densification by as much as 1
9%. Gaussian decomposition showed a broadening and a significant shift
of the initial absorption bands at 5.11 and 5.42 eV. A threefold decr
ease of the 3.15-eV luminescence band was revealed, whereas the 4.25-e
V luminescence band was only slightly sensitive to densification. This
shows that these two bands belong to different luminescence centers.
A drastic growth of a new metastable absorption band near 7.3 eV was o
bserved. The pressure-induced changes disappeared as a result of therm
al annealing. These changes are discussed with respect to in-fiber gra
ting phenomena. (C) 1997 Optical Society of America.