A solid-state three-dimensional upconversion display

We demonstrate a novel solid-state three-dimensional display using rare earth doped heavy metal fluoride glass as the active medium. In this device, two laser beams intersect inside a bulk glass at room temperature to address a pixel in three-dimensional space. The two-step resonant upconversion process requires two different infrared wavelengths to produce visible radiation. In this manner, a pixel can be addressed only at the intersection of the two laser beams. By scanning the intersection of these beams inside the display material, true three-dimensional figures can be drawn. For practical applications with high bit densities and low power pump lasers, high upconversion efficiency is necessary. Recent work on upconversion in fluoride glasses, motivated by fiber amplifier and short wavelength laser development, has identified fluoride glass hosts and rare earth dopants as systems that have high radiative recombination rates and high upconversion efficiencies. In this presentation we demonstrate three-dimensional displays in both trivalent praseodymium (Pr/sup 3+/:ZBLAN) and in trivalent thulium (Tm/sup 3+/:ZBLAN) doped bulk fluoride glass. >