| 摘要 |
A real-time, multi-color image [36] is displayed in a flat screen [20] composed of a low-phonon, optically transparent, non-pixelated host material doped with active ions. The display uses intersecting infrared laser beams [22, 24] of different wavelengths to induce a two-frequency upconversion process in the active ions at a point [28] in the screen. When the ions relax, visible fluorescence is produced. Different points in the display are activated by directing the laser beams [22, 24] to intersect at different locations within the screen. In one embodiment, beams from two lasers [28, 30] are controlled by single axis mirrors [32, 34]. In other embodiments, laser arrays or slab lasers are used to activate points within the screen. Through the use of additional lasers and dopants, multi-color images may be displayed. The doped host material is tailored to provide efficient upconversion in the region of intersection, with minimal visible light generated outside this region by either one of the infrared beams alone. Typical media are rare-earth-doped glasses or crystals having low phonon energies. The general methods for selecting and producing the display material, along with a plurality of system configurations for addressing the display, are disclosed.
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