On the lasing potency of samarium-activated BaSO₄–TeO₂–B₂O₃ glass host: Judd–Ofelt analysis

Abstract

The quest for optimized rare earth glass host is ever-increasing. Multi-component telluro-borate glass matrices are excellent rare earth host due to their unique spectroscopic traits. Inspired by this idea, a series of (70-y)B₂O₃–15BaSO₄–15TeO₂–ySm₂O₃ glasses were fabricated using melt-quenching method. The measured spectroscopic features were complemented by Judd–Ofelt (JO) analysis. The absorption spectra of as-quenched samples revealed nine bands in the ultraviolet–near-infrared regions. The photoluminescence (PL) emission spectra displayed four emission channels: moderate green, orange, moderate red, and a weak red emission of Sm³⁺ transitions. The observed quenching in the PL intensity of the glasses prepared with y > 1.0 mol% was attributed to the binary cross-relaxation mechanisms. The calculated JO intensity parameters Ω₂, Ω₄, and Ω₆ were ranged from 1.48 to 4.20 (× 10⁻²⁰ cm²), 2.31–4.31 (× 10⁻²⁰ cm²) and 1.15–1.99 (× 10⁻²⁰ cm²), respectively. Moreover, the small values of Ω₂ disclosed the weak covalent nature of network co-ordination in the neighborhood of Sm³⁺ sites. The ⁴G_5/2 to ⁶H_7/2 transition of Sm³⁺ disclosed the highest branching ratio (68.8%), emission cross section (75.90 × 10⁻²³ cm²), gain bandwidth (167.69 × 10⁻²⁹ cm³), and optical gain (172.01 × 10⁻²⁶ cm² s⁻¹) for BSTBSm0.5 glass. Briefly, the proposed glass composition may be a potential host for visible waveguide laser application.