Broad Band Excitation of Rare-Earth Dopants in Chalcogenide Glasses
Photoluminescence characterization has discovered a novel broad bands excitation effect in rare earth-doped chalcogenide glasses. Photoluminescence excitation (PLE) bands with a width of $\sim$450 nm have been observed which efficiently excite a number of rare earth emission lines. This effect is attributed to the absorption of excitation light by the host glass with the subsequent transfer of energy to the rare earth dopants, mediated by defect states in the glass. Studies on the effect of changing the rare earth dopant, the host glass bandgap, the host glass composition, and the sample temperature have all been performed. From numerous similarities to the host glass PLE lineshape, fatiguing, temperature dependence, and the spectral range over which the effect occurs, the defect states in the glass responsible for the broad band PLE are identified as being the same states which give rise to the host glass luminescence in chalcogenide glasses. The theoretical implications of this identification are explored.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign