Optical absorption and near infrared emission properties of Nd3+ ions in alkali lead tellurofluoroborate glasses

Nd3+ doped H3BO3–PbO–TeO2–RF (R = Li, Na and K) glasses were prepared through melt quenching technique. Optical absorption and near infrared (NIR) fluorescence spectra were recorded at room temperature. The spectral intensities were analyzed in terms of the Judd–Ofelt (J–O) parameters (Ωλ = 2, 4, 6). The covalency effect of Nd–O bond on the J–O parameters was estimated from the relative absorbance ratio (R) between 4I9/2 → 4F7/2 and 4I9/2 → 4S3/2 transitions. The effect of Nd–O covalency on the Ω4 and Ω6 intensity parameters as well as on the spontaneous emission probabilities (AR) was discussed. Lomheim and Shazer hybrid method was applied to determine the fluorescence branching ratios (βR) of each emission transition from the 4F3/2 metastable level to its lower lying levels. The evaluated total radiative transition probabilities (AT), stimulated emission cross-sections (σe) and gain bandwidth parameters (σe × ΔλP) were compared with the earlier reports.

Fig. Variation of fluorescence branching ratio (βR) (red line) and the intermultiplet branching ratio of (βR(F4→I4))/(βR(F4→I4)) (Blue line) with (Ω4/Ω6) ratio for 4F3/2 emission level of Nd3+ ions in RLTB glasses.Figure optionsDownload as PowerPoint slide