Optical transitions and upconversion luminescence of Er 3+-doped tellurite glass

Abstract

Spectroscopic properties of Er 3+-doped TeO 2–WO 3–Bi 2O 3 (TWB) glass has been investigated. The transition probabilities, excited state lifetimes, and the branching ratios have been predicted for Er 3+ based on the Judd–Ofelt theory. The lifetime of 4I 11/2 and 4I 13/2 level were measured from time-resolved fluorescence decay. The mutiphonon relaxation of 4I 11/2→ 4I 13/2 transition in TWB glass was predicted and compared with other glass hosts. Efficient green and weak red upconversion luminescence from Er 3+ centers in the glass sample was observed at room temperature, and the upconversion excitation processes have been analyzed.