Compositional dependence of the luminescence properties of Nd3+ ions in lead phosphate glasses: The efficient laser active materials

Abstract

Spectroscopic investigations on 1 mol% Nd3+ embedded xPbO + (100-x) P2O5 (where x = 40, 50, and 60 mol %) glasses have been reported. Adopting a free-ion Hamiltonian, the energy values and the free-ion parameters are determined. Judd-Ofelt intensity parameters (Ω2, Ω4, Ω6) of Nd3+ ions in lead phosphate glasses are evaluated. Symmetry and covalency of Nd3+ ions are studied with increasing PbO contents in the host glasses. Strong emission due to 4F3/2 → 4I11/2 transition at 1055 nm in the near infrared (NIR) region is observed in the glasses upon excitation at 585 nm. Using the Judd-Ofelt intensity parameters, the radiative transition probability (AR), branching ratio (βR), radiative decay lifetime (τR), stimulated emission cross-section (σP), optical gain parameter and gain bandwidth are calculated for the 4F3/2 metastable state of Nd3+ ion. The luminescence lifetimes are estimated from the decay profiles. Various luminescence parameters for 4F3/2 → 4IJ (J = 9/2, 11/2 and 13/2) transitions are compared with some commercially available Neodymium doped phosphate-based laser glasses. Our investigation indicates that the present glasses could be utilized as the more efficient laser active materials for emission in the NIR region at 1055 nm.