Spectroscopic properties of Yb 3+ and Er 3+ ions in heavy metal glasses

Abstract

Selected heavy metal glasses containing Yb 3+ and Er 3+ ions have been studied. Near-infrared luminescence spectra at 1.53 μm and up-conversion spectra of Er 3+ ions were registered under excitation of Yb 3+ ions by 975 nm diode laser line. The luminescence bands correspond to 4I 13/2– 4I 15/2 (NIR), 4S 3/2– 4I 15/2 (green) and 4F 9/2– 4I 15/2 (red) transitions of Er 3+, 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 4I 13/2– 4I 15/2 transition of Er 3+ ions in Yb–Er co-doped lead borate glass was obtained, whereas long-lived NIR luminescence at 1.53 μm 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.