Luminescent studies of Dy3+ ion in alkali lead tellurofluoroborate glasses

Dy3+-doped alkali lead tellurofluoroborate (RLTB) glasses (R=Li, Na and K) were prepared by melt quenching technique. Judd-Ofelt theory has been used to evaluate the three intensity parameters Ω2, Ω4 and Ω6 from the experimental oscillator strengths. The photoluminescence spectra obtained by the excitation wavelength of 385 nm show four emission bands at 454, 483, 575 and 665 nm corresponding to the 4I15/2→6H15/2 and 4F9/2→6HJ/2 (J=15/2, 13/2 and 11/2) transitions, respectively. The laser characteristic parameters like fullwidth at half maxima (FWHM), stimulated emission cross-sections (σe), optical gain parameters (σe×τexp) and gain bandwidth parameters (σe×FWHM) were determined. From the visible emission spectra, yellow to blue (Y/B) intensity ratios and chromaticity coordinates were also estimated. The lifetimes of 4F9/2 metastable state were also measured and discussed.

Research Highlights► RLTB system is a novel host for optical absorption and luminescence studies. ► KLTB glass exhibits a greater degree of covalency for Dy-O bond. ► Decay curves of 4F79/2 state show bi-exponential behaviour in all the glasses. ► Dy3+ doped RLTB glasses are the good materials for solid state lasers. ► Dy3+: RLTB glasses are suitable materials for white light emission.