Spectroscopic properties of Nd^3+ and Pr^3+ in gallate glasses with low phonon energies

Abstract
Absorption and fluorescence spectra of Nd3+ were measured in potassium tantalum gallate, lead bismuth gallate (PBG), fluorozirconate (ZBLAN), and Ge-Ga-S glasses. A Judd–Ofelt analysis was performed to determine the spontaneous emission probability and stimulated emission cross section of the 4F3/24I11/2 transition of Nd3+. Raman spectra were studied to clarify the maximum phonon energies of the glasses. The fluorescence of the 1G43H5 transition of Pr3+ in a dehydrated PBG glass was observed for the first time to our knowledge. The PBG glass has a higher quantum efficiency than that of ZBLAN glass based on the Judd–Ofelt analysis.