A. Bluiett (Elizabeth City State University)
A comparative study of the wavelength dependence of the Er3+ upconversion in low phonon-energy hosts KPb2Cl5 and KPb2 Br5 will be presented. Initial measurements indicate that visible and infrared upconversion was generated under 0.97 um and 1.5 um laser excitation. Using time resolved emission, spectral emission, and spectral absorption data the dominant upconversion mechanisms involving excited state absorption and/or energy transfer were investigated. In addition, special emphasis was geared toward a comparative study of the detrimental effects of upconversion under resonant pumping conditions (1.5 um) for possible applications in the eye-safe wavelengths (1.5 -- 1.6 um) region.