Concentration quenched luminescence and energy transfer analysis of Nd ions doped Ba-Al-metaphosphate laser glasses

This paper reports the dopant ion (Nd) concentration effects on its luminescence properties in a new glass system based on barium-alumino-metaphosphates. Amongst the studied concentrations range of 0.276 – 13.31 x 10 ions/cm, the glass with 2.879 x 10 ions/cm (1 mol%) Ndconcentration shows intense NIR emission from F3/2 excited state, followed by a decrease in emission intensity for further increase in Nd ion concentration. The observed luminescence quenching is ascribed to Nd self-quenching through donor-donor migration assisted cross-relaxation mechanism. The microscopic energy transfer parameters for donor-acceptor energy transfer, CDA and donor-donor energy migration, CDD have been obtained from the theoretical fittings to experimental decay curves and the spectral overlap model respectively. The CDD parameters (x 10 -39 cm/sec) are found to be about three orders greater than that of CDA (x 10 -42 cm/sec) for Nd self-quenching in this host, demonstrating the excitation energy migration among donors is due to hopping mechanism. The energy transfer micoparameters obtained in the present study are comparable to the values reported for commercially available laser glasses LHG-8 and Q-98. PACS: 32.50.+d, 42.70.Hj, 78.55.Qr, 78.40.-q