Spectral Investigations of Dy<sup>3+</sup>-Doped Gd<sub>2</sub>O<sub>3</sub>-CaO-P<sub>2</sub>O<sub>5</sub> Glasses

Abstract

Dy3+-doped phosphate glasses of the compositions 20Gd2O3 : 10CaO : (70-x)P2O5 : xDy2O3, where x = 0.05, 0.10, 0.50, 1.00 and 1.50 mol% have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. All the transitions in the absorption spectra are originated from the 6H15/2 ground level to the various excited states and these are intra configuration (f-f) transitions. The observed twelve absorption bands centered at 349, 362, 387, 425, 451, 473, 750, 800, 895, 1089, 1266 and 1676 nm are assigned to 6P7/2, 4P3/2, 4F7/2, 4G11/2, 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6H9/2 and 6H11/2 transitions, respectively. The absorption spectra of glasses increase with increase in Dy3+ ion concentrations. The emission spectra of Dy3+-doped glasses are observed to be centered at 483, 573, 662 and 752 nm originated from the 4F9/2→6H15/2, 4F9/2→6H13/2, 4F9/2→6H11/2 and 4F9/2→6H9/2 transitions, respectively under excitation at 349 nm. The highest emission intensity of Dy3+-doped glass is 0.50 mol% due to concentration quenching effect. The experimental lifetimes are found to decrease when Dy3+ ion concentrations increased due to energy transfer process between Dy3+ ions.