Europium doping in monoclinic KYb(WO4)2 crystal.

We report on a detailed spectroscopic study of Eu 3+ ions in the monoclinic KYb(WO 4 ) 2 crystal. The polarized room and low-temperature absorption spectra are measured. The maximum σ abs corresponding to the 7 F 1 → 5 D 1 transition is 1.32×10 –20 cm 2 at 534.2 nm with a bandwidth of 0.7 nm (for E || N m ). The Stark sub-levels of the excited mulitplets are determined. A Judd-Ofelt analysis is applied to the Eu 3+ :KYb(WO 4 ) 2 crystal to determine the probability of spontaneous transitions, radiative lifetimes and luminescence branching ratios. Within the strong configuration interaction (SCI) approximation, the intensity parameters are Ω 2 =4.757, Ω 4 =2.295, Ω 6 =1.644 [10 –20 cm 2 ] and Δ f =50160 cm –1 . The radiative lifetime of the 5 D 0 state is 351 µs. The maximum stimulated-emission cross-section corresponding to the 7 F 1 → 5 D 1 transition is 1.44×10 –20 cm 2 at 703.2 nm (for E || N m ). Under UV excitation, the Eu 3+ :KYb(WO 4 ) 2 crystal provides intense red photoluminescence with CIE coordinates, x=0.675, y=0.325. [ABSTRACT FROM AUTHOR]