Lasing transition at 1.06 μm emission in Nd³⁺‐doped borate‐based tellurium calcium zinc niobium oxide glasses for high‐power solid‐state lasers

Abstract

The spectroscopic properties of Tellurium Calcium Zinc Niobium oxide Borate (TCZNB) glasses of composition (in mol%) 10TeO₂ + 15CaO + 5ZnO + 10 Nb₂ O₅ + (60 - x)B₂ O₃ + Nd₂ O₃ (x = 0.1, 0.5, 1.0 or 1.5 mol%) have been investigated experimentally. The three phenomenological intensity parameters Ω₂ , Ω_4, Ω₆ have been calculated using the Judd-Ofelt theory and in turn radiative properties such as radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes have been estimated. The trend found in the JO intensity parameter is Ω₂ > Ω₆ > Ω₄ If Ω₆ > Ω₄ , the glass system is favourable for the laser emission ⁴ F₃_/2 → ⁴ I₁₁_/2 in the infrared (IR) wavelength. The experimental values of branching ratio of ⁴ F₃_/2 → ⁴ I₁₁_/2 transition indicate favourable lasing action with low threshold power. The evaluated total radiative transition probabilities (A_T ), stimulated emission cross-section (σ_e ) and gain bandwidth parameters (σ_e × Δλ_p ) were compared with earlier reports. An energy level analysis has been carried out considering the experimental energy positions of the absorption and emission bands.