Red, green, and blue upconversion luminescence in ytterbium-sensitized praseodymium-doped lead-cadmium-germanate glass

摘要

Blue, green, red, and near-infrared upconversion luminescence in the wavelength region of 480 - 740 nm in Pr~(3+)/Yb -codoped lead-cadmium-germanate glas under 980 nm diode laser excitation, is presented. Upconversion emission paks around 485, 530, 610, 645, and 725 nm which were ascribed to the ~3P_0 - ~3H_J (J=4, 5, and 6), and ~3P - ~3F_J (J=2, and 3,4), transitions, respectively, were observed. The population of the praseodymium upper 3P0 emitting level was accomplished through a combination of ground-state absorption of Yb~(3+) ions at the ~2F_(7/2), energy-transfer Yb~(3+)(~2F_(5/2)) -Pr~(3+)(~3H_4), and excited-state absorption of Pr~(3+) ions provoking the ~1G_4 - ~3P_0 transition. The dependence of the upconversion luminescence upon the Yb~(3+)-concentration and diode laser power, is also examined, in order to subsidize the proposed upconversion excitation mechanism.