Optical properties of Dy3+-doped sodium–aluminum–phosphate glasses

Trivalent dysprosium (Dy 3+ )-doped sodium–aluminum–phosphate (NAP) glasses were prepared and characterized by their optical absorption, excitation, emission spectra, and decay time measurements. Judd–Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime and stimulated emission cross section of the 4 F 9/2 → 6 H 13/2 and 4 F 9/2 → 6 H 15/2 transitions. The luminescence intensity ratio of 4 F 9/2 → 6 H 13/2 to 4 F 9/2 → 6 H 15/2 transitions of Dy 3+ in NAP glasses gives the feasibility of extracting white light. The lifetime and quantum efficiency of 4 F 9/2 level is found to be higher than other reported glasses. With increase in Dy 3+ ion concentration, the decay from 4 F 9/2 level is found to be faster with decrease in lifetime due to cross relaxation between Dy 3+ ions.