Spectroscopic investigations of 1.06 μm emission in Nd 3+-doped alkali niobium zinc tellurite glasses

Abstract

Thermal, structural and optical properties of Nd 3+ ions in tellurite glass (TeO 2–ZnO–Na 2O–Li 2O–Nb 2O 5) have been investigated. Differential thermal analysis revealed reasonably good forming tendency of the glass composition. FTIR spectra were used to analyze the functional groups present in the glass. Judd–Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime, branching ratio and stimulated emission cross-section of the 4F 3 /2 → 4I 9/2, 11 /2, 13/2 transitions. The quantum efficiency of the 4F 3 /2 level is comparable as well as higher than the typical value of the other tellurite based glasses. The decay from the 4F 3/2 level is found to be single exponential for different concentrations of Nd 3+ ions with a shortening of lifetime with increasing concentration. The experimental values of branching ratio and saturation intensity of 4F 3/2→ 4I 11/2 transition indicate the favourable lasing action with low threshold power.