Optical and radiation shielding properties of Sm³⁺ ions embedded bismuth-based fluorophosphate glasses for γ-ray shielding and multi-band visible laser applications

Bismuth based fluorophosphate (PBNS) glasses doped with samarium ions were fabricated by well-known melt quenching method. The structural, optical and fluorescence properties of PBNS glasses, were extensively investigated via XRD, FTIR, EDAX, optical absorption and fluorescence emission along with lifetime decay analysis. The intensity parameters (Ω₂, Ω₄, Ω₆) were calculated using the Judd – Ofelt hypothesis, which follows the Ω₄ > Ω₆ >Ω₂ trend. PBNSSm glasses doped with 1.0 mol% samarium ions (PBNSSm10) had a greater emission peak intensity than the produced glasses according to the emission spectra. The ⁴G_5/2 → ⁶H_7/2 transition emitting the radiation at 597 nm was more intense than the other transitions and got higher values for optical gain bandwidth (10.70 x 10⁻²⁵ cm³), stimulated emission cross-section (10.05 x 10⁻²⁰ cm²) branching ratio (0.48), and optical gain parameter (28.65 x 10⁻²⁵ cm²s). The emission spectral results have been used to evaluate the colorimetric analysis of the 1931 CIE coordinates, and CCT values fall in the visible spectrum region. Moreover, the degree of protection of the synthesized PBNS glasses against gamma radiation was also evaluated. The obtained results suggested that the PBNS glass doped with 1.0 Sm³⁺ ions could be useful for multi-band visible laser applications. It was also concluded that 2.0% Sm³⁺ addition effectively increases the gamma-ray shielding properties of PBNS glasses, and therefore PBNSSm20 can be an alternative shielding material.