Optical properties and radiative rates of Nd3+ doped zinc-sodium phosphate glasses

Abstract

Preparation using melt quenching technique and optical characterizations of Nd3+ doped Zn-Na phosphate glasses are presented. The structure of the present glasses was studied using X-ray diffraction and FT-IR spectroscopy. UV-vis spectra of the present glasses were analyzed at different concentrations of Nd2O3. The effect of neodymium concentration on the density and energy band gap was investigated. The density of the present glasses slightly increases with the increasing of Nd2O3. A small variation of energy band gap with the increasing of neodymium content is observed as well, while Eg values decrease with the increase of Nd2O3 content. The Eg values lie between 4.36 and 4.69 eV. Based on the measured optical spectra, Judd-Ofelt theory was used to determine the optical parameters such as line strengths, optical intensity parameters (Ωt), transition probabilities, and transition lifetimes. Hypersensitive transitions were identified in the absorption spectrum, the greatest line strengths are recorded at the transitions 2G7/2 + 4G5/2, 4S3/2 + 4F7/2 and 4D1/2 + 4D3/2 + 4D5/2 + 2I11/2 with wavelengths of 580, 475 and 355 nm, respectively. Lifetimes of the important 4F3/2 laser-level were determined; which show decreasing trend with the increasing of Nd2O3 content and are found to be between 0.838 and 1.595 ms. The uncertainty of the present results was estimated. The RMS deviations were determined, which show lower values than those in the literature.