Spectroscopic and Judd-Ofelt Analysis of Nd3+ Ion Doped Lithium Antimony-Borate Glasses for Visible and Near Infrared Laser Application Compared to Standard Emission at 1.06 μm

Abstract

The present work focuses on the spectroscopic luminescence analysis of trivalent neodymium-doped lithium antimony-borate glasses, with the glass composition 70 Sb2O3—(25-x) B2O3–5 Li2O—x Nd2O3 where x = 0.3; 0.5; 0.7 mol% (SBLN). Around 475 nm excitation used by the transition 4I9/2 → 2G9/2 + 2D3/2 + 2K15/2 and that induced emission lines of wavelengths λ emis = 584;673;767;826 nm (red is low intensity). The specific emission follows the transitions 2G7/2 + 4G5/2 → 4IJ (J = 9/2; 11/2; 13/2; 15/2). Previous work on Nd3+ doped glasses studied near-infrared emission in 4F3/2 → 4IJ mode (J = 9/2; 11/2; 13/2) via near-infrared excitation 4I9/2 → 4F5/ 2+2H9/2. The Judd-Ofelt analysis applied to SBLN glasses showed that the ΩK parameters are consistent with the values in the literature. SBLN7 glass has the best spectroscopic factor Ω4/Ω6 = 0.974; while the best luminescence branching ratio is that of the green emission and it stands at an average β = 70%. Similarly, green emission has the best values of stimulated emission cross section and gain bandwidth. Calculated and measured lifetimes are ranged between 15 and 40 microseconds; however, quantum efficiency varies between 50 and 91%. In another side calculated and measured refractive index values are very close. The chromatic coordinates of observed green color showed accurately that lies in the yellowish-green region of the chromaticity diagram edited by CIE 1931. The calculation of its temperature was made by Mc Macy’s equation, and it is in the limits of 5100 K; which corresponds to a cool color similar to midday sunlight.