Ultraviolet and violet upconversion luminescence in Er 3+ -doped yttrium aluminum garnet crystals

摘要: The ultraviolet and violet upconverted luminescence around 320, 410, 470 nm in ${\mathrm{Er}}^{3+}$-doped yttrium aluminum garnet has been observed at room temperature with a tunable OPO laser excitation. upconversion mechanisms upon ${}^{4}{S}_{3/2}$ excitation $(\ensuremath{\approx}545 \mathrm{nm})$ are investigated by means of the decay profiles upconvered spectrum. It appears that, depending on excited wavelength, is dominantly contributed either energy-transfer or excited-state absorption. relative intensities discussed using Judd-Ofelt theory.