Concentration‐dependent studies of Nd3+‐doped zinc phosphate glasses for NIR photoluminescence at 1.05 μm

Abstract

Nd3+ -doped lead-free zinc phosphate glasses with the chemical compositions (60-x) NH4 H2 PO4 +20ZnO+10BaF2 +10NaF+xNd2 O3 (where x=0.5, 1.0, 1.5, 2.0 and 2.5mol%) were prepared using a melt quenching technique. Vibrational bands were assigned and clearly elucidated by Raman spectral profiles for all the glass samples. Judd-Ofelt (J-O) intensity parameters (Ωλ : λ=2, 4, 6) were obtained from the spectral intensities of different absorption bands of Nd3+ ions. Radiative properties such as radiative transition probabilities (AR ), radiative lifetimes (τR ) and branching ratios (βR ) for different excited states were calculated using J-O parameters. The near infrared (NIR) photoluminescence spectra exhibited three emission bands (4 F3/2 level to 4 I13/2 , 4 I11/2 and 4 I9/2 states) for all the concentrations of Nd3+ ions. Various luminescence properties were studied by varying the Nd3+ concentration for the three spectral profiles. Fluorescence decay curves of the 4 F3/2 level were recorded. The energy transfer mechanism that leads to quenching of the 4 F3/2 state lifetimes was discussed at higher concentration of Nd3+ ions. These glasses are suggested as suitable hosts to produce efficient lasing action in NIR region at 1.05μm.