Analysis of the dynamics of frequency upconversion in Er(su3+}/Yb(su3+} co-doped KY(WO4)2 crystal

The absorption spectra and the luminescence decay curve of Er
³⁺
/Yb
³⁺
co-doped KY(WO
4
)
2
crystal was measured. The radiative transition rates were calculated by Judd-Ofelt theory. The Yb-to-Er energy-transfer rate and the cooperative upconversion coefficients were estimated by numerically solving the rate equations and fitting simulated curve to the measured data.