Yellow-green upconversion luminescence of Dy3+ ion in LiNbO3 crystal heavily codoped with ZnO.

The observed Dy3+ ion upconversion luminescence in LiNbO3 crystal heavily codoped with ZnO was spectrally and temporally analyzed by microsecond time-resolved spectrum under 806 nm intense femtosecond laser excitation at room temperature. Absorption spectrum and modified Judd-Ofelt approach were used to investigate its spectroscopic properties. The bright blue and intense yellow emissions are assigned to transitions 4F9/2→6H15/2 and 4F9/2→6H13/2, respectively. It is concluded that the main upconversion mechanism is excited state absorption by pump power dependence in combination with luminescence intensity temporal evolvements. [ABSTRACT FROM AUTHOR]