Analysis of the dynamics of frequency upconversion in Er~(3+)/Yb~(3+) co-doped KY(WO_4)_2 crystal

摘要

The absorption spectrum, upconversion spectrum and the fluorescence decay curve of Er~(3+)/Yb~(3+) co-doped KY(WO_4)_2 crystal were measured. The radiative transition rates were calculated by Judd-Ofelt theory. A model for the dynamics of frequency upconversion process in Er~(3+)/Yb~(3+) co-doped KY(WO_4)_2 crystal was proposed. The Yb-to-Er energy transfer rate and the upconversion coefficients were estimated by numerically solving the rate equations and fitting simulated curve to the experimental data.