The infrared to visible up-conversion emissions in Yb 3+-Tm 3+ co-doped KGd_2F_7 samples excited at 980 nm was reported. The observed up-conversion emissions include intense blue 1G_4→3H_6 (482 nm) transition and oth...The infrared to visible up-conversion emissions in Yb 3+-Tm 3+ co-doped KGd_2F_7 samples excited at 980 nm was reported. The observed up-conversion emissions include intense blue 1G_4→3H_6 (482 nm) transition and other weak transitions: 1D_2→3H_6 (367 nm), 1G_4→3F_4 (651 nm) and 1G_4→3H_5 (776 nm). The concentration quenching of Tm 3+ or Yb 3+ is obvious at higher concentration due to the cross-relaxation. The optimum doping levels are 10% Yb 3+ and 0.2%～0.4% Tm 3+ for blue emission. Power studies reveal that the blue emission of Tm 3+ ion results from three-photon processes, which require three energy transfers from Yb 3+ to excite Tm 3+ from 3H_6 to 1G_4 in succession.展开更多
文摘The infrared to visible up-conversion emissions in Yb 3+-Tm 3+ co-doped KGd_2F_7 samples excited at 980 nm was reported. The observed up-conversion emissions include intense blue 1G_4→3H_6 (482 nm) transition and other weak transitions: 1D_2→3H_6 (367 nm), 1G_4→3F_4 (651 nm) and 1G_4→3H_5 (776 nm). The concentration quenching of Tm 3+ or Yb 3+ is obvious at higher concentration due to the cross-relaxation. The optimum doping levels are 10% Yb 3+ and 0.2%～0.4% Tm 3+ for blue emission. Power studies reveal that the blue emission of Tm 3+ ion results from three-photon processes, which require three energy transfers from Yb 3+ to excite Tm 3+ from 3H_6 to 1G_4 in succession.
