Abstract:
THE PHOTOCHROMIC PROPERTIES OF CAF2 AND SRF2 CONTAINING LA ARE ENHANCED BY THE ADDITION OF NA OR K THERETO. THE PHOTOCHROMIC MATERIAL IS PREPARED BY SLOWLY COOLING IN A TEMPERATURE GRADIENT, A MELT COMPRISING THE APPROPRIATE RATIOS OF THE VARIOUS METAL FLUORIDES IN THE PRESENCE OF A SEED CYRSTAL. THE AS-GROWN MATERIAL IS THEN TREATED EITHER UNDER GAMMA IRRADIATION OR IN A REDUCING ATMOSPHERE.
Abstract:
A film of a single crystal lithium niobate film on a platinum coated lithium tantalate crystal can be prepared by depositing a thin layer of platinum on a polished lithium tantalate crystal surface, depositing a layer of finely divided lithium niobate on the platinum and fusing the lithium niobate. Such films are useful in optical waveguide electro-optic modulators and acoustic surface wave devices.
Abstract:
Single crystal electro-optic material useful for recording phase holograms consists of lithium niobate doped with iron or manganese or lithium tantalate doped with iron. These crystals may also contain other dopants together with the iron or manganese.
Abstract:
AN IMAGE DISPLAY AND STORAGE DEVICE HAS A PHOTOCHROMIC IMAGE SCREEN CONSISTING OF SODALITE HAVING THE BASIC CHEMICAL COMPOSITION NA6A16SI6O24-2NAX WHEREIN X IS AT LEAST ONE HALOGEN SELECTED FROM THE GROUP CONSISTING OF CHLORINE, BROMINE AND IODINE AND WHEREIN THE SODALITE CONTAINS FROM AT LEAST 50 PARTS PER MILLION OF IRON UP TO THE SOLUBILITY LIMIT OF IRON IN THE SODALITE. THE SODALITE IS ANNEALED IN A REDUCING ATMOSPHERE TO PRODUCE ITS PHOTOCHROMIC PROPERTIES. SUCH AN IMGE SCREEN DARKENS UPON EXPOSURES TO ULTRAVIOLET LIGHT OR CATHODE RAY EXCITATION. AN ESPECIALLY HIGH CONTRAST RATIO IMAGE SCREEN CAN BE ATTAINED UTILIZING SODALITE DOPED WITH IRON WHICH IS TREATED BY HEATING THE SODALITE IN A FUSED ALKALI HALIDE SALT BATH.