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AssigneeKernforschungsanlage Julich Gesellschaft mit beschrankter Haftung
InventorsTheo Woike, Wolfgang Krasser, Siegfried Haussuhl
Estimating the term…
Nitroprusside single crystals having the formula M.sub.n [Fe(CN).sub.5 ]nH.sub.2 O, where M is a metal that forms a nitroprusside is found to have the property, when cooled to a temperature in the range between 160.degree. K. and 250.degree. K., of convertability into a long-duration metastable state by irradiation with coherent blue-green light and to return to the original state when irradiated with red light. Barium nitroprusside Ba[Fe(CN).sub.5 ]2H.sub.2 O can be switched rapidly from one state to the other without requiring cooling below about 200.degree. K. and lends itself particularly well to making single crystal memories for writing with a blue-green laser beam and reading with a red laser beam, with the readout being picked up by a photodetector diode array, on which the radiation from the nitroprusside crystal is focused. The incident laser beams are pulsed and the photodetector is turned off during pulsing. Movable laser mirrors are used to direct the laser beams to locations on the surface of the crystal in a manner controlled by an address program.
Optical switch capable of use for information storage, utilizing a medium capable of being converted from an original state to a metastable state by a radiative pumping by intensive light having a first wavelength (.lambda..sub.1) and capable of being returned to said original state by intensive light having a second wavelength (.lambda..sub.2), comprising a source of light of said first and second wavelengths, said storage medium, means for directing radiation of said first and second wavelengths for localized incidence on said medium and photodetector means for measuring radiation coming from said medium,
Dependencies are inferred from the claim text.