Structural and luminescence studies of Ho³⁺-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (A_R), branching ratios (β_R), radiative lifetimes (τ_R) were calculated and discussed. From the emission spectra emission peak positions (λ_P), effective bandwidths (Δλ_eff) and stimulated emission cross-sections (σ_P) were calculated for the observed emission transitions,⁵S₂ (⁵F₄→⁵I₈) and ⁵F₅→⁵I₈ in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation