Multiwavelength visible and white light generation by upconversion emission in Ho/Tm/Yb triply doped fluorogermanate glass-ceramic

Abstract

Energy transfer excited multiwavelength visible upconversion emission and white light generation is described in a single sample ofPbGeO 3-PbF2-CdF2 glass-ceramic triply doped with Ho/Tm/Yb under single infrared laser excitation. Blue (475 nm), green (540 nm), and red (650 nm), upconversion luminescence signals are generated, and the emissions are assigned, respectively, to thulium (1G4- 3H6), and holmium (5S2) →5F4)→5I8, 5F5→5I8 ions transitions, both excited via successive energy transfers from ytterbium ions. It is experimentally shown that with a proper combination of the rare earth ions contents, white light may be produced, with the simultaneous generation of fluorescence with controllable intensities at the wavelengths of the three primary colours in a single sample and using a single near-infrared excitation source.