The effect of host glass on optical absorption and fluorescence of Nd³⁺in<i>x</i>Na₂O–(30 <i>x</i>)K₂O–70B₂O₃glasses

Abstract

The effect of host glass composition on the optical absorption and fluorescence spectra of Nd3+ has been studied in mixed alkali borate glasses of the type xNa2O–(30− x)K2O–69.5B2O3–0.5Nd2O3 (x = 5, 10, 15, 20 and 25). Various spectroscopic parameters such as Racah (E1, E2 and E3), spin–orbit (ξ4f) and configuration interaction (α,β) parameters have been calculated. The Judd–Ofelt intensity parameters (Ωλ) have been calculated and the radiative transition probabilities (Arad),radiative lifetimes (τr), branching ratios (β) and integrated absorption cross sections (Σ) have been obtained for certain excited states of the Nd3+ ion and are discussed with respect to x. From the fluorescence spectra, the effective fluorescence line widths (Δλeff) and stimulated emission cross sections (σp) have been obtained for the three transitions , and of Nd3+. The stimulated emission cross section (σp) values are found to be in the range (2.0–4.8) × 10−20 cm2 and they are large enough to indicate that the mixed alkali borate glasses could be potential laser host materials.