Spectroscopic properties of germanium oxygen-deficient centers were studied in vapor axial deposition and modified chemical-vapor deposition germanosilicate glass after hydrostatic densification by as much as 19%. Gaussian decomposition showed a broadening and a significant shift of the initial absorption bands at 5.11 and 5.42 eV. A threefold decrease of the 3.15-eV luminescence band was revealed, whereas the 4.25-eV 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 observed. The pressure-induced changes disappeared as a result of thermal annealing. These changes are discussed with respect to in-fiber grating phenomena.
© 1997 Optical Society of America
E. M. Dianov, V. M. Mashinsky, V. B. Neustruev, O. D. Sazhin, V. V. Brazhkin, and V. A. Sidorov, "Optical absorption and luminescence of germanium oxygen-deficient centers in densified germanosilicate glass," Opt. Lett. 22, 1089-1091 (1997)