초록 ▼

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 proc

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.

대표청구항 ▼

[ I claim:] [1.] A display comprising:a screen comprising a first layer of a first low phonon optically transparent host material doped with a first active ion species;a first infrared light source adapted to generate a first beam of photons having a first wavelength, and to direct the first beam in

[ I claim:] [1.] A display comprising:a screen comprising a first layer of a first low phonon optically transparent host material doped with a first active ion species;a first infrared light source adapted to generate a first beam of photons having a first wavelength, and to direct the first beam into the first layer through an edge surface of the first layer; anda second infrared light source adapted to generate a second beam of photons having a second wavelength not equal to the first wavelength, and to direct the second beam into the first layer through an edge surface of the first layer;wherein the first active ion species has a ground state, an intermediate state, and an excited state such that photons having the first wavelength excite the first active ion from the ground state to the intermediate state, photons having the second wavelength excite the first active ion from the intermediate state to the excited state, and wherein relaxation from the excited state to the ground state produces visible fluorescence.