Abstract: A narrow-band filter for absorbing radiation at a wavelength in the range of 9.2 to 10.8 microns and for transmitting radiation in a surrounding 8 to 12 micron band having a high transmission ratio. The filter is comprised of a pure or mixed alkali-halide crystal having optical incidence and transmission surfaces and thiocyanate or borofluoride as an impurity.

Abstract: An optical control element is disclosed which is capable of accomplishing the simplifying, small-sizing and lightening of the structure. The optical control element comprises a substrate exhibiting both an optical function and a magnetic function and a Cd.sub.1-x Mn.sub.x Te directly deposited on the substrate.

Abstract: An optically transmittant body comprising a solid solution of a ternary sulfide and a selected binary sulfide such as a solid solution of calcium lanthanum sulfide and phase lanthanum sulfide is provided by precipitating out of a nitrate solution of calcium and lanthanum, a starting powder of calcium carbonate and lanthanum carbonate. The molar ratio of lanthanum to calcium is greater than 2.0 moles lanthanum to 1.0 moles of calcium nitrate. The starting powder is reacted with a sulfurizing agent such as hydrogen sulfide to convert such starting powder into a powder of the solid solution of calcium lanthanum sulfide and phase lanthanum sulfide. The precipitate ion reaction forms a homogenous fine particle size starting powder of calcium carbonate and lanthanum carbonate which is substantially and uniformly converted into the solid solution powder. The phase lanthanum sulfide has a similar crystallographic structure as the calcium lanthanum sulfide.

Abstract: The color filter of this invention comprises a transparent substrate, a porous activated film layer formed on the substrate and made of activated alumina or activated silica or a mixture thereof, a colored area or a pattern formed by the dye fixed in the minute pores of the activated film layer, and a coating layer sealingly closing the upper portions of the minute pores of said activated film layer. This color filter is relatively simple and easy to manufacture, superior in resistivity to heat, water, chemicals, solvents, etc. and suitable for use as a color filter in various display devices, particularly liquid crystal display devices.

Abstract: A photochromic and/or cathodochromic sodalite material according to the invention represents a transparent monolith with a homogeneous polycrystalline structure and has a density in excess of 99% of the theoretical density of sodalite with an identical chemical composition. Such material is prepared by hot moulding of the sodalite powder obtained by any method under conditions preventing intense evaporation of alkali halides and incongruent melting of the sodalite. The sensing element of the prepared material is made in the form of a plate with its thickness chosen according to the desired sensitivity of radiation registration and the desired contrast ratio of the image stored as the sensing element is in transparent mode of operation.

Abstract: The improvement of the electrolytic and additive methods of coloring alkali fluoride crystals comprising the step of selecting an alkali fluoride crystal having the impurities of between 0 and 5 ppmA of OH; between 0 and 50 ppmA of one or more alkaline earth cations, of which between 0 and 10 ppmA Mg.sup.++ and between 0 and 10 ppmA Ca.sup.++ ; between 0 and 50 ppmA of non-fluorine halide anions; between 0 and 10 ppmA of SiF.sub.6.sup.= ; between 0 and 30 ppmA of other ions; and the method of preparing these crystals which comprises converting the alkali fluoride to alkali hydrofluoride, crystallizing and vacuum drying the alkali hydrofluoride crystals, regenerating the alkali fluoride by expelling hydrogen fluoride, and crystallizing the alkali fluoride.

Abstract: Coarse particle size zinc sulfide is treated with a solution of alkali metal halide to make it adaptable for hot-pressing into shaped, polycrystalline windows which is more transparent in the visible to near visible and infrared spectral regions than untreated coarse particle size zinc sulfide.

Abstract: An ultraviolet optical filter is provided having a first filter element including a 2,7-dimethyl-diaza-(3,6)-cycloheptadien-(1,6)-perchlorate and second filter element including a crystal of thallium doped potassium iodide. A method for filtering light is also disclosed.

Abstract: A mixtureand method are disclosed for growing bismuth lutetium iron garnet crystals via liquid phase epitaxy on a gadolinium gallium garnet (GGG) substrate wherein the crystals exhibit a relatively high Faraday rotation and an improved optical absorption.