Abstract: An optical filter that uses multiple reflections to provide spectral bandpass filtering of ultraviolet, visible and infrared radiation with a very high transmission of wavelengths within a selected passband coupled with exceptional off-band rejection. The reflection filter uses dielectric-coated spherical reflectors or mirrors manufactured with absorbing glass substrates. The multiple-pass feature of the reflection filter is achieved using a traditional long-path absorption cell such as a White Cell or Wilkes Cell. The light transmitted through the reflection filter is only that light which has undergone multiple reflections as the wavelengths of high mirror reflectivity reflect off the dielectric-coated substrates. All remaining light at wavelengths corresponding to high mirror transmission is attenuated by absorption in the mirror substrate.

Abstract: Gold is useful for infrared polarization-insensitive mirrors on silica. However, gold does not adhere to bare silica. The adherence is enhanced by depositing an optically thin glue layer of Ni-P on a silica surface after sensitization of the surface with SnF.sub.2 and activation with PdCl.sub.2 /HCl. The Ni-P layer is deposited in a thickness sufficient to enhance adherence of gold to the surface of silica but insufficient to act as a barrier to the passage of infrared radiation to or from the gold layer. One measure of the Ni-P thickness is the absorbance of the glue layer of >0.008 at 550 nm (>0.003 at 850 nm) as measured by a spectrophotometer. A 100-150 nm thick gold layer, deposited by e-beam deposition on this adhesion layer, adheres well enough to pass the commonly used "Scotch tape adhesion test". The ability to make gold adhere to silica with very low optical loss is useful in fabrication of lightwave devices which require the use of reflecting surfaces, such as on optical fibers or waveguides.

Abstract: An absorbing anti-reflection coating which can be applied directly to the faceplate of a video display such as a cathode ray tube or a plasma display by physical or chemical vapor deposition comprises at least 3 materials: L, a low retractive index material such as the metal oxide SiO.sub.2 ; H, a high refractive index material such as the metal oxide Nb.sub.2 O.sub.5 ; and M, a metal or metallic alloy or metallic compound layer with a refractive index greater than 0.5 and extinction coefficient less than 5. Preferably the materials are used in the design MHLHL or HMHL. The design and materials provide broadband performance with a low layer count. The single metal layer design permits relatively low values of sheet resistance (high conductivity). Transmittance values are high, typically 70%.+-.5%. Reflectance typically is .ltoreq.0.6%.

Abstract: A metal or ceramic matrix composite part and corresponding method are provided exhibiting desired heat transfer characteristics. The part has a metal or ceramic matrix composite substrate and a multilayer dielectric coating. The coating has high reflectivity at wave lengths corresponding to radiation wavelengths of various combustion gases and has low reflectance at radiation wavelengths corresponding to the substrate. The multilayer coating allows the heat generated external of the part at wavelengths corresponding to combustion gases to be reflected from the part while permitting radiation wavelengths associated with the substrate to pass through the coating. The parts are useful for use in combustive gas atmospheres.

Abstract: Low-cost composite infrared windows that are transparent to long wave infrared radiation (8-12 microns) that provide sufficient strength and impact resistance for automotive-type environments, and the like. The windows may be used with night vision systems for automobiles, surveillance imaging systems, and other applications requiring low cost, long wave infrared windows. In one embodiment, the composite infrared window is a sandwich comprised of a polyethylene plastic film bonded with an acrylic adhesive to a relatively thin (0.015-0.040 inch) silicon substrate. The thin silicon substrate is mechanically stiff and low cost, and transmits in the 8-12 micron bandpass. The thin (0.001-0.007 inch) plastic film provides an exterior particle impact absorbing layer sufficient to enable the use of the window in automotive applications.

Abstract: A mirror for, e.g, an excimer laser is disclosed having high reflectance for a broad band of wavelengths in the ultraviolet range exhibiting excellent adhesion and "laser durability." The mirror comprises a substrate formed from glass or a glass-like material, a dielectric film, and a metallic film, such as aluminum foil, positioned between the dielectric film and the substrate. The dielectric film includes alternating layers of high- and low-refractive index material. These alternating layers reduce the amount of incident light reaching the metallic film so that any damage to the metallic film caused by light is reduced, thereby increasing the laser durability of the mirror. The laser durability is also increased because the durability of the laminated dielectric film is generally superior to that of the metallic film used in prior-art metallic reflector mirrors.

Abstract: A coated substrate comprises a transparent substrate, a lower coating on the transparent substrate, a functional layer on the lower coating, and an upper coating on the functional layer. The lower coating has a first layer comprising silicon or a metal, and nitrogen or oxygen, and a second layer comprising zinc oxide and having a thickness of at least 16 nm. The second layer is in contact with the functional layer.

Abstract: A mirror including a glass substrate, a reflective layer of chromium on the substrate, and a reactively sputtered overcoat of titanium nitride.

Abstract: Transparent articles comprising transparent, nonmetallic substrate and a transparent film stack is sputter deposited on the substrate. The film stack is characterized by including at least one infrared reflective metal film, a dielectric film over the metal film, and a protective silicon nitride film of 10 .ANG. to 150 .ANG. in thickness over the said dielectric film. The dielectric film desirably has substantially the same index of refraction as does silicon nitride and is contiguous with the silicon nitride film.

Abstract: A high reflectivity, broad band mirror for a high flux laser and a process for producing such a mirror. The mirror includes a substrate on which is formed a metallic layer such as aluminum. A stack of layers are formed on the metallic layer. The stack includes alternating layers of two materials with the refractive index of one material being higher than that of the other. A surface layer of a third material is placed on the stack. The surface layer has a refractive index which varies in accordance with the continuous periodic profile. The mirror is formed by depositing the metallic layer on a substrate and forming the stack by an ion beam sputtering method.

Abstract: A reflector formed on a base with a thick (0.5 to 2.0 microns) layer of non-porous oxide underlying an aluminum vacuum deposited layer which supports a pair of quarter wavelength reflectance-enhancing layers.

Abstract: An optical thin film for an optical element is disclosed, which includes at least one layer containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3. A material for use in evaporation coating to prepare a thin film includes a mixture of at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3 and another dielectric. A further optical thin film includes a substrate and superimposed thereon are alternate layers. One such alternative layer having a high refractive index, and composed of a material containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3. Another of such alternative layers having a low refractive index, and composed of SiO.sub.2. Another thin film includes a substrate and, superimposed thereon, at least one dielectric layer. The at least one dielectric layer being at least one layer containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.

Abstract: In order to produce lightweight mirror structures or other reflecting components, preformed silicon elements of sufficient wall thickness are applied to a CFC or CMC substrate structure with the dimensions of the component to be produced, at a temperature in the range 1300.degree. C. and 1600.degree. C. either in vacuum or in a protective atmosphere. In this way a mirror structure or reflector is formed directly. It is possible to work at temperatures in the range of 300.degree. C. to 600.degree. C. when the silicon is applied in the form of a preform such as a wafer, which is joined to the substrate by way of a zone of a melt eutectic incorporating a nonferrous metal, which is preferably gold. The surfaces are subsequently coated.

Abstract: A semiconductor window which is transparent to light in the infrared range and which has good electrical conductivity is formed of a prefabricated semiconductor sheet bonded to a substrate material by optical contact. The sheet is a substantially uniformly doped wafer sufficiently thin that inherent absorption bands do not affect transmission. The sheet is contact bonded to the surface of an undoped transparent substrate without diffusion, growth or deposition on the surface. Windows having particular optical band pass characteristics are formed utilizing a zinc selenide substrate and a gallium arsenide sheet.

Abstract: A very low reflectance optical coating comprising alternating layers of materials such as chromium oxide and chromium, silicon oxide and silicon, titanium oxide and titanium, and tantalum oxide and tantalum is suitable for use as a black shadow mask in liquid crystal displays, among various applications. Certain designs such as silicon oxide/silicon benefit from a transmission-decreasing overcoat of material such as molybdenum, germanium or titanium.

Abstract: An improved way to impart antireflection properties to light transmissive substrates and, at the same time, achieve a durable surface and electrical conductivity is disclosed. A stack of at least two sputter-deposited light transmissive inorganic layers, one of which being electrically conductive and having a high index of refraction with the one above it (relative to the substrate being antireflected) having a low index of refraction, in combination with a thin lubricating overlayer comprising a solvent-soluble lubricant such as a solvent-soluble fluoropolymer can achieve this desired combination of properties.

Abstract: A window includes a first layer of a dielectric first material that transmits radiation in the visible or the infrared, and a second layer positioned adjacent to the first layer. The window is positioned so that the radiation is incident upon the first layer. The second layer is formed of a dielectric or semiconductor second material that transmits radiation in the same wavelength range as the first material. A first electrical conductor lies between the first layer and the second layer. A second electrical conductor lies on at least one of an exterior surface of the first layer remote from the second layer and an interior surface of the second layer remote from the first layer. Where the first and second materials are selected to transmit in the infrared, the first and second electrical conductors are grids. Where the first and second materials are selected to transmit light in the visible, the first and second electrical conductors are continuous layers.

Abstract: The durability of thin metal coatings and particularly substantially transparent copper and silver plus noble metal coatings and their ability to withstand corrosive environments is improved by overcoating the metal layers with a double coating of dielectric. The first coating is made up of dielectric based on indium and/or zinc. The second coating is made up of dielectric based on indium and tin. These overcoatings are more effective than a single coating based on one metal or a single coating based upon the two metals.

Abstract: A laminate which comprises a transparent substrate, a first oxide layer comprising ZnO which contains at least one metal, a first metallic layer comprising Pd-containing Ag and a second oxide layer comprising SnO.sub.2 or ZnO which contains at least one metal, wherein said layers are formed on the substrate in this order.

Abstract: Reflector having a composite reflectivity enhancing layer as reflecting surface layer on a reflector body where the said composite has a sandwich structure with an aluminum layer facing the reflector body, an outer layer, the HI-layer, with a refractive index n.sub.2 facing the radiation to be reflected, and an intermediate aluminum oxide layer, the LI-layer, with a refractive index n.sub.1 which is smaller than n.sub.2. The LI-layer is a transparent and pore-free barrier layer produced by anodic oxidation of the aluminum layer and having a dielectric constant .epsilon..sub.1 of 6 to 10.5 at 20.degree. C. and the optical layer thickness d.sub.opt.1 of the LI-layer and d.sub.opt.2 of the HI-layer are such thatd.sub.opt,i =d.sub.i.n.sub.i =l.sub.i..lambda./4.+-.10 nm, i=1, 2where d.sub.1 represents the thickness of the LI-layer in nm, d.sub.2 the thickness of the HI-layer in nm, .lambda. the average wave length in nm of the light striking the reflector surface and l.sub.1, l.sub.2, uneven natural numbers.

Abstract: This invention is directed to a glass substrate having deposited thereon an electroconductive coating useful for defrosting the glass. The coating comprises three layers. The first layer deposited on the glass is selected from the group consisting essentially of: (a) silicon oxide and (b) silicon nitride and it is deposited on at least a portion of a surface of the glass substrate. The second layer comprises an electrically conductive material selected from the group consisting essentially of (a) aluminum doped zinc oxide and (b) gallium doped zinc oxide. It is deposited on at least a portion of the first layer in a thickness of at least 1 micron. This second layer has a sheet resistance of less than 20 ohms per square. A third layer comprising a protective material is deposited on and is at least coextensive with the second layer. It is deposited in a thickness of at least 10 microns and is selected from the group of materials consisting essentially of: (a) fluorine doped tin oxide, and (b) silicon nitride.

Abstract: A elemental mirror for vehicles having a luminous reflectance of at least about 30% includes a substrate coated with a thin layer of elemental semiconductor having an index of refraction of at least 3 and an optical thickness of at least about 275 angstroms. Preferably, the elemental semiconductor coating is sputter coated silicon or germanium and a light absorbing coating is included therebehind. The mirror is spectrally nonselective with elemental semiconductor optical thicknesses of about 275 to 2400 angstroms on the front substrate surface. Spectrally selective mirrors are provided by adding an interference coating to the elemental semiconductor layer coating, preferably of a dielectric such as silicon dioxide or silicon nitride, on either the front or rear substrate surface, or by using a thicker, single elemental semiconductor layer. Instead of an absorbing coating behind the mirror, additional elemental semiconductor and dielectric thin layers may be included to reduce secondary reflections.

Abstract: An improved way to impart antireflection properties to light transmissive substrates and, at the same time, achieve a durable surface and electrical conductivity is disclosed. A stack of at least two sputter-deposited light transmissive inorganic layers, one of which being electrically conductive and having a high index of refraction with the one above it (relative to the substrate being antireflected) having a low index of refraction, in combination with a thin lubricating overlayer comprising a solvent-soluble lubricant such as a solvent-soluble fluoropolymer can achieve this desired combination of properties.

Abstract: An optical filter arrangement comprises at least two optical filter elements including a transparent substrate and an optical coating typically comprising at least two overlying optical thin films. The coating defines a first patterned area and a second surround area bordering the first area. The first area has substantially the same optical transmittance characteristics as the second area and different optical reflectance characteristics over at least a portion of the visible spectrum. The distinction between the first area and the second area is visually perceptible when viewed from one side of the optical filter arrangement and is substantially visually imperceptible when viewed from the opposite side of the optical filter arrangement. As a result, a coloured pattern or logo is only visible when viewed from one side of the filter arrangement. The invention extends to a method of forming such an arrangement.

Abstract: An optical device comprising an electrode (<200 ohms/square) that is transparent to infrared radiation through and beyond the mid-wavelength infrared (3-5 micrometers), and long wavelength infrared (8-12 micrometers), out to 30 micrometers. The optical device is comprised of a sandwich of a thin (.ltoreq.0.001") conductive silicon wafer optically contacted or bonded to an optically transparent substrate. Typical substrates that may be employed are cadmium telluride, zinc sulfide or zinc selenide substrates. The substrate provides the rigidity necessary to prevent optical distortion which can result from bowing caused by mounting stresses. The optical device provides an electrode having high infrared transmission without the optical diffraction effects produced by a conductive grid. Unlike conductive coatings, the optical device does not incur transmission degradation caused by temperature increases.

Abstract: A photoelectric transducer is provided which comprises a first electrode, a second electrode constituted of an antireflection layer, and a semiconductor layer between the first electrode and the second electrode. The antireflection layer comprises a laminated member of a first tin oxide layer containing a first crystalline oxide of grain size of not larger than 20 nm, and a second thin oxide layer containing a second oxide of a second thin oxide layer containing a second crystalline oxide of grain size of not larger than 20 nm.

Abstract: An anti-reflection coating that is soil resistant and easy to maintain is provided. The coating includes a multilayer film having alternating layers of high and low refractive index materials that comprise electrically conductive metal oxides. The film is formed by reacting metal with non-stoichiometric amounts of oxygen such that the coating has one or more layers of electrically conductive metal oxide material. The coating is particularly suited for ophthalmic applications.

Abstract: A metal-coated multilayer mirror having high reflectivity and high specularity. The mirror comprises a multilayered polymer film and a reflective metal layer. The multilayered polymer film preferably comprises layers of a crystalline, semi-crystalline, or liquid crystalline material, such as a naphthalene dicarboxylic acid polyester, having an average thickness of not more than 0.5 microns and layers of a second polymer having an average thickness of not more than 0.5 microns. Preferably, the layers of semi-crystalline naphthalene dicarboxylic acid polyester have a positive stress optical coefficient. The reflective metal layer comprises a metal selected from the group consisting of silver, gold, aluminum, nickel, copper, and titanium, with silver and aluminum being particularly preferred. The metal-coated multilayer mirrors are useful in applications requiring broad bandwidth reflection, high specularity, low manufacturing costs, and high reflectivity.

Abstract: A light absorptive antireflector comprising a substrate, a light absorbing film formed on the substrate and a silica film formed on the light absorbing film, to reduce reflection of incident light from the silica film side, wherein the geometrical film thickness of the light absorbing film is from 5 to 25 nm, and the geometrical film thickness of the silica film is from 70 to 110 nm.

Abstract: A reflection mirror of a projection display unit which displays a stereoscopic image through a light polarization glasses, reflects a linearly polarized light emitted from a projection source through a polarizing plate toward a screen. The reflection mirror includes: a glass substrate; a metal film provided on the glass substrate; a first dielectric film provided on the metal film; and a second dielectric film provided on the first dielectric film, wherein each of the first and second dielectric films includes a predetermined thickness and a predetermined refractive index so that a phase difference between a p-polarized light of a reflected light and a s-polarized light of the reflected light is within a range from -45 degree to 45 degree in case of an incident angle of the linearly polarized light being varied from 0 degree to 45 degree.

Abstract: A sputter-coated layer system including a non-nitrided and non-oxidized nickel or nickel alloy layer located between two layers of Si.sub.3 N.sub.4 of the requisite thicknesses and used for architectural and automotive glass substrates so as to be heat treatable and have .DELTA.E characteristics sufficiently low to render the products matchable as between heat treated and non-heat treated products having the same coating thereon.

Abstract: A hard and durable single-layer or multilayer artireflection coating for use with a high refractive-index IR transparent substrate is provided. The coating is prepared by concurrent deposition of TiO.sub.2 and MgF.sub.2 with the reactive ion-assistance on the IR transparent substrate within a single vacuum chamber. The refractive-index of this film is adjustable by varying the relative deposition rate of the two materials (i.e. controlling the ratio of the materials) to optimize the transmittance of the incident IR irradiation. The opitical thickness of each film of the single-layer and multilayer antireflection coatings is one-quarter wavelength of the IR irradiation.

Abstract: Hard coatings are fabricated from multilayer boron/boron carbide, boron carbide/cubic boron nitride, and boron/boron nitride/boron carbide, and the fabrication thereof involves magnetron sputtering in a selected atmosphere. These hard coatings may be applied to tools and engine and other parts, as well to reduce wear on tribological surfaces and electronic devices. These boron coatings contain no morphological growth features. For example, the boron and boron carbide used in forming the multilayers are formed in an inert (e.g. argon) atmosphere, while the cubic boron nitride is formed in a reactive (e.g. nitrogen) atmosphere. The multilayer boron/boron carbide, and boron carbide/cubic boron nitride is produced by depositing alternate layers of boron, cubic boron nitride or boron carbide, with the alternate layers having a thickness of 1 nanometer to 1 micrometer, and at least the interfaces of the layers may be of a discrete or a blended or graded composition.

Abstract: An electroconductive antireflection film with a laminated structure is composed of at least four oxide layers, including a plurality of high-refractive-index layers and a plurality of low-refractive-index layers, at least one of the high-refractive-index layers serving as a transparent electroconductive layer and one of the low-refractive-index layers serving as a surface layer.

Abstract: Glass composites, containing a glass substrate (1) on which is deposited an underlying film (2) based on tantalum oxide, titanium oxide or tin oxide, on which is deposited a functional film (3) based on an alloy of chromium and nickel or based on tantalum, on which is deposited an overlying film (4) based on titanium oxide, titanium nitride or tantalum oxide, provide effective protection against solar radiation while exhibiting excellent wear and corrosion resistance.

Abstract: Method for optimizing an optical assay device for an analyte, including the steps of: providing a substrate having a chosen thickness of an optically active layer thereon; providing an attachment layer of a chosen thickness on the optical coating; providing a receptive layer of a chosen thickness for the analyte, wherein at least one of the thicknesses of the optically active layer, attachment layer and receptive layer is varied to provide a plurality of thicknesses of that layer; contacting analyte with the receptive layer under conditions in which an increase in mass on the receptive layer results; and determining the optical thickness of the layer.

Abstract: A mirror coating which provides improved performance characteristics to a mirror assembly and which includes a non-periodic succession of materials which exhibit neutral reflected chromaticity and a luminous reflectance of greater than 50%.

Abstract: An arrangement is produced for protection against harmful effects of radiation and for indicating such radiation which can preferably be designed as a viewing window or as goggles and can be used for protecting the eyes from injury due to high-intensity electromagnetic radiation. It includes a transparent substrate and a sequence of thin optical layers which are applied to this substrate and are arranged according to the principle of an optical thin-film resonance absorber system.

Abstract: A transparent substrate (i), particularly glass, having a stack of thin films comprising successively form the substrate:i) a first dielectric material film;ii) a first film having infrared reflection properties;iii) a second dielectric material film;iv) a second film having infrared reflection properties;v) a third dielectric material film;vi) a third film having infrared reflection properties; andvii) a fourth dielectric material film, wherein the thickness of said third film having infrared reflection properties (vi) is greater than the thickness of said second film having infrared reflection properties (iv) and the thickness of said second film having infrared reflection properties (iv) is greater than the thickness of said first film having infrared reflection properties (ii).

Abstract: In a multi-layer coating for a material of good transparency for visible light, with an emissivity e<0.04 and a light transmission T.gtoreq.78% and with two silver layers of different thickness, three oxide coatings are provided, and very thin metal or metal suboxide coatings as blockers, the oxide layers being alloys of the metals SnMg, SnAl, SnZr, SnTi or SnTa.

Abstract: An apparatus and method for equalizing the signal strengths of different scan lines which employs an attenuating mirror. The attenuating mirror attenuates a laser beam and reflected light from an article at an attenuation which is different from the attenuation of another pattern mirror so that reflected light from the one and the other pattern mirror have intensities which are substantially equal, within a predetermined range of intensities having a low end equal to a signal-to-noise threshold and a high end equal to a saturation level.

Abstract: The adhesion to plastic substrates of thick layers of functional metals having an oxide heat of formation that is greater than -40,000 calories/gram atom of metal, such as silver, copper, gold, and the like, is improved if a thin layer of a metal having an oxide heat of formation of less than -50,000 calories/gram atom of metal is present as an adhesion-promoting primer layer. When the primer layer metal has a melting point greater than 1100.degree. C., it should be present as the metal or as a substoichiometric oxide. When the primer layer metal has a melting point less than 1100.degree. C., it may be present as the metal, as a substoichiometric oxide, or as a full stoichiometric oxide. Processes for preparing these materials using sputter-depositing and reflectors incorporating these materials are also disclosed.

Abstract: In a conductive antireflection film having predetermined optical characteristics, of the layers of the conductive antireflection film, two layers located on the transparent substrate side are replaced with a three-layered film having a metal oxide film as an intermediate layer thereof. In this three-layered film when k.sub.i =4n.sub.i d.sub.i .lambda..sub.0 (where n.sub.i is the refractive index of the ith layer, di is the geometric thickness of the ith layer, and .lambda..sub.0 is a middle wavelength in design), the metal oxide film as the second layer satisfies k.sub.2 .gtoreq.0.01, and an ITO film as the first layer satisfies k.sub.1 .gtoreq.0.1.

Abstract: A high-reflectivity surface reflecting mirror is provided by sequentially forming, on a resin substrate, a silicon dioxide first under layer, a chromium sulfide second under layer, a silver reflecting layer and protective layers. According to a second aspect of the invention, a surface reflecting mirror is provided by sequentially forming, on a resin substrate, a silicon dioxide under layer, an aluminum reflecting layer, a silicon dioxide first protective layer, a second protective layer made of at least one of titanium oxide, tantalum oxide and zirconium oxide, and an aluminum oxide third protective layer.

Abstract: A multilayer antireflection coating for a temperature sensitive substrate such as plastic. One layer is a DC reactively sputtered metal oxide which may be deposited quickly and without imparting a large amount of heat to the substrate. Another layer has a refractive index lower than the substrate.

Abstract: A method of producing heatable mirrors comprising depositing onto a ribbon of hot glass during the production process a reflecting coating whereby the mirrors so formed have a visible light reflection of at least 70% and depositing an electroconductive heating layer onto the mirrors. There is also provided a heatable mirror comprising a glass substrate carrying a non-metallic reflecting coating whereby the mirror has a visible light reflection of at least 70% and an electroconductive heating layer deposited on the coated substrate.

Abstract: A method of heat-treating multilayer interference platelets to improve the durability of the platelets comprising subjecting the platelets at a temperature of 200.degree.-300.degree. C. for 10 minutes to 24 hours. The platelets are formed from a multilayer interference thin film construction comprising a metal reflecting layer having a multilayer interference thin film structure on both sides of the metal reflecting layer wherein the multilayer interference thin film structure comprises a pair of layers consisting of a dielectric layer and a semi-opaque metal layer with the dielectric layer of the pair being directly adjacent to the metal reflecting layer.

Abstract: A color-shifting paint comprising a polymeric paint medium and a plurality of colored interference thin film platelets dispersed in the paint medium. Each platelet being characterized in that platelets has first and second generally planar outer surfaces and an edge thickness perpendicular to the first and second generally planar outer surfaces. Each platelet is comprised of a metal reflecting layer having first and second surfaces. A multilayer interference structure is disposed on each of the first and second surfaces of the metal reflecting layer to provide a symmetrical platelet. The multilayer interference thin film structure comprises a pair of layer consisting of a dielectric layer formed of a dielectric material and a semi-opaque layer. with the dielectric layer directly adjacent to the metal reflecting layer. The thickness of the dielectric layer determines the color and the dielectric material determines the degree of color shift.

Abstract: A collection of color-shifting interference thin film platelets of high chroma characterized in that the platelets are comprised of a metal reflecting layer having first and second surfaces and a multilayer interference thin film structure disposed on both surfaces of the metal reflecting layer. The multilayer interference thin film structure comprises a pair of layers consisting of a dielectric layer and a semi-opaque metal layer with the dielectric layer being directly adjacent to a surface of the metal reflecting layer. The layers of the multilayer interference thin film structure lie in parallel planes. Each platelet has an aspect ratio of at least 2:1, respectively, for surfaces parallel to the planes of layers and surfaces perpendicular to the planes of the layers. The platelets have a maximum dimension on any surface ranging from approximately 2-200 microns.

Abstract: A reflective liquid crystal light valve includes transparent conductive layers of indium tin oxide (30) employed as an electrode to electrically modulate orientation of molecules of a liquid crystal material that receives a high intensity reading light (40) applied through the transparent electrode. Unwanted double reflection (64,66) from interfaces between the indium tin oxide electrode (30) and adjacent layers (22,32) are minimized by application of broad band anti-reflective coatings (70,72,74,76) formed by one or more pairs of thin layers having alternately high and low indices of refraction.