Spectroscopy of Tb3+ ions in monoclinic KLu(WO4)2 crystal application of an intermediate configuration interaction theory.

The spectroscopic properties of Tb 3+ ions in monoclinic KLu(WO 4 ) 2 double tungstate crystal are studied with polarized light. The absorption spectra in the visible, near- and mid-IR including the transitions to all lower-lying 7 F J ( J  = 0 … 5) excited states are measured. The maximum absorption cross-section for the 7 F 6  →  5 D 4 transition is 3.42 × 10 −21  cm 2  at 486.7 nm for light polarization E || N m . The transition probabilities for Tb 3+ ions are calculated within the Judd-Ofelt theory modified for the case of an intermediate configuration interaction (ICI). The radiative lifetime of the 5 D 4 state is 450 μs and the luminescence quantum yield is >90%. The polarized stimulated-emission cross-section spectra for all 5 D 4  →  7 F J ( J  = 0 … 6) emission channels are evaluated. The maximum σ SE is 11.4 × 10 −21  cm 2  at 549.4 nm (for E || N m ). Tb 3+ :KLu(WO 4 ) 2 features high transition cross-sections for polarized light being promising for color-tunable visible lasers and imaging. [ABSTRACT FROM AUTHOR]