Er3+ -doped oxyfluoroborosilicate glass ceramics with embedded CaF2 nanoparticles for 1.53 μm broad band applications

The CaF₂ based oxyfluoroborosilicate glasses and glass ceramics doped with Er³⁺ ions were prepared via melt quench process followed by heat treatment and characterized for 1.53 μm broadband applications. The optimized glass ceramic sample was obtained at 450^oC/1h heat treatment. The Er³⁺ concentration was optimized as 1.0 mol% for efficient emission at 460 nm excitation through concentration dependent luminescence analysis. The spectroscopic parameters such as Ω_λ = 2,4,6 parameters and the radiative parameters such as spontaneous transition probability rates (A_R), branching ratios (β_R) and decay times (τ_R) were calculated applying the standard Judd-Ofelt theory. The effective bandwidth (Δλ_eff), stimulated emission cross-section (σ_e), gain bandwidth (σ_e × Δλ_eff), quantum efficiency (η) and figure of merit (σ_e × τ_R) were calculated as 25.78 nm, 13.42 × 10⁻²¹ cm², 3.46 × 10⁻²⁶ cm³, 82.83% and 5.32 × 10⁻²³ cm²s, respectively for the optimized glass ceramic sample. The exchange type of energy transfer among the excited Er³⁺ ions results the quenching in luminescence and the non-exponentiality in decay curves. The systematic investigations carried out indicate that the glass ceramic obtained at 450^oC/1h heat treatment was proficient for 1.53 μm broadband fiber lasers and optical amplifiers in S and C band communication window.