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

The spectroscopic properties of Tellurium Calcium Zinc Niobium oxide Borate (TCZNB) glasses of composition (in mol%) 10TeO2 + 15CaO + 5ZnO + 10 Nb2O5 + (60 - x)B2O3 + Nd2O3 (x = 0.1, 0.5, 1.0 or 1.5 mol%) have been investigated experimentally. The three phenomenological intensity parameters Ω2, Ω4, Ω]6 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 4F3/2 → 4I11/2 in the infrared (IR) wavelength. The experimental values of branching ratio of 4F3/2 → 4I11/2 transition indicate favourable lasing action with low threshold power. The evaluated total radiative transition probabilities (AT), stimulated emission cross-section (σe) and gain bandwidth parameters (σe × Δλp) were compared with earlier reports. An energy level analysis has been carried out considering the experimental energy positions of the absorption and emission bands.