Spectroscopic properties of Yb3+ and Er3+ ions in heavy metal glasses

Selected heavy metal glasses containing Yb3+ and Er3+ ions have been studied. Near-infrared luminescence spectra at 1.53 mu m and up-conversion spectra of Er3+ ions were registered under excitation of Yb3+ ions by 975 nm diode laser line. The luminescence bands correspond to I-4(13/2)-I-4(15/2) (NIR), S-4(3/2)-I-4(15/2) (green) and F-4(9/2)-I-4(15/2) (red) transitions of Er3+, respectively. The optical transitions of rare earth ions have been examined as a function of glass host. The unusual large spectral linewidth nearly close to 110 nm for I-4(13/2)-I-4(15/2) transition of Er3+ ions in Yb-Er co-doped lead borate glass was obtained, whereas long-lived NIR luminescence at 1.53 mu m was detected in lead germanate glass. The NIR luminescence and up-conversion phenomena strongly depend on stretching vibrations of glass host, which was confirmed by FT-IR spectroscopy. (C) 2011 Elsevier B.V. All rights reserved.