Abstract: An interferometric modulator (Imod) cavity has a reflector and an induced absorber. A direct view reflective flat panel display may include an array of the modulators. Adjacent spacers of different thicknesses are fabricated on a substrate by a lift-off technique used to pattern the spacers which are deposited separately, each deposition providing a different thickness of spacer. Or a patterned photoresist may be used to allow for an etching process to selectively etch back the thickness of a spacer which was deposited in a single deposition. A full-color static graphical image may be formed of combined patterns of interferometric modulator cavities. Each cavity includes a reflector, and an induced absorber, the induced absorber including a spacer having a thickness that defines a color associated with the cavity.

Abstract: An optical body comprising (a) a dielectric multilayer film having a reflecting band positioned to reflect infrared radiation of at least one polarization at an incident angle normal to the film, said reflecting band having a short wavelength bandedge .lambda..sub.a0 and long wavelength bandedge .lambda..sub.b0 at a normal incident angle, and a short wavelength bandedge .lambda..sub.a.theta. and long wavelength bandedge .lambda..sub.b.theta. at a maximum usage angle .theta., wherein .theta..sub.a.theta. is less than .lambda..sub.a0 and .lambda..sub.a0 is selectively positioned at a wavelength greater than about 700 nm; and (b) at least one component which at least partially absorbs or reflects radiation in the wavelength region between .lambda..sub.a.theta. and .lambda..sub.a0 at a normal angle of incidence.

Abstract: An optical receiver board wherein, a signal light is amplified in an optical fiber amplifier. The amplified signal light is supplied to an electrically driven optical wavelength-tuning filter such as a multi-layered film interference filter, through which a signal light of a predetermined wavelength bandwidth is transmitted. The transmitted signal light is divided into first and second signal lights. The first signal light is converted to an electric signal which is amplified by an equalizing amplifier, and an amplified electric signal is supplied to a discrimination circuit, in which an information electric signal is generated by using a timing signal. The optical wavelength-tuning filter comprises a rotation actuator having a magnet-rotating portion and control coils, and an optical filter member fixed to the top of the magnet-rotating portion.

Abstract: An interferometric modulator (Imod) cavity has a reflector and an induced absorber. A direct view reflective flat panel display may include an array of the modulators. Adjacent spacers of different thicknesses are fabricated on a substrate by a lift-off technique used to pattern the spacers which are deposited separately, each deposition providing a different thickness of spacer. Or a patterned photoresist may be used to allow for an etching process to selectively etch back the thickness of a spacer which was deposited in a single deposition. A full-color static graphical image may be formed of combined patterns of interferometric modulator cavities. Each cavity includes a reflector, and an induced absorber, the induced absorber including a spacer having a thickness that defines a color associated with the cavity.

Abstract: A multi-band pupil stop is disclosed for use in multi-band focal plane array imaging systems. The object is to provide similar point spread functions at the focal plane array. The pupil stop is comprised of one or more nested annuli. Each annulus is a pass-band filter with the outermost annulus passing the longest wavelength waveband and each successive inner annulus passing a successively shorter wavelength waveband. The pass-band of each annulus is such that the ratio of the center wavelength of each pass-band to the outer diameter of each annulus is approximately equal.

Abstract: A solar control film having low visible light transmittance and low visible light reflectance is comprised of a first sheet of transparent substrate material having deposited thereon a solar-load-reduction film for preferentially reducing infrared light energy transmitted through the film, and a second sheet of transparent substrate material having deposited thereon a thin, transparent film of metal effective to partially block light transmittance, wherein the first sheet of transparent substrate and the second sheet of transparent substrate are separated by an optically massive layer that prevents the constructive and destructive interference of reflected light. A preferred embodiment of a solar control film includes, in order, a pressure-sensitive adhesive layer, a polyethylene terephthalate layer, a Fabry-Perot interference filter layer, an adhesive layer, a grey metal layer, another polyethylene terephthalate layer, and a hardcoat layer.

Abstract: An optical filter, for absorbing a part of the optical signals with a central wavelength .lambda. and restricting the intensity of the transmitted light, includes a dielectric block with a high refractive index, a metal film, and a dielectric block with a low refractive index deposited on a substrate in that order in the direction of the incident light.

Abstract: Interference filters and filter arrays based on thin-metal film interference filters having at least one dielectric layer formed between two thin-metal films to form a Fabry-Perot cavity.

Abstract: By applying a photonic signal to a microresonator that includes a photonic bandgap delay apparatus having a photonic band edge transmission resonance at the frequency of the photonic signal, the microresonator imparts a predetermined delay to the photonic signal. The photonic bandgap delay apparatus also preferably has a photonic band edge transmission resonance bandwidth which is at least as wide as the bandwidth of the photonic signal such that a uniform delay is imparted over the entire bandwidth of the photonic signal. The microresonator also includes a microresonator cavity, typically defined by a pair of switchable mirrors, within which the photonic bandgap delay apparatus is disposed. By requiring the photonic signal to oscillate within the microresonator cavity so as to pass through the photonic bandgap delay apparatus several times, the microresonator can controllably impart an adjustable delay to the photonic signal.

Abstract: An operation microscope includes an illuminating device and an interference filter in the illuminating beam of the illuminating device. The interference filter is suitable for incorporation into the operation microscope. In order to prevent the yellow tinge that is present in long-known UV interference filters, the interference layer applied directly to the carrier substrate is a layer between 8 and 12 nm thick of yttrium fluoride, thorium fluoride, lanthanum fluoride or cerium fluoride.

Abstract: A filter (10) for selectively transmitting electromagnetic energy over a range of frequencies (28, 30, 32) adapted for use with white light (24). The filter (10) includes rugate layers (18, 20) for creating a resonant cavity that resonates at desired bandpass frequencies (28, 30, 32). An absorptive layer (12) absorbs frequencies near the bandpass frequencies (28, 30, 32) and reflects frequencies outside the bandpass frequencies (28, 30, 32). Phase matching layers (14, 16) allow the transmission of electromagnetic energy within the transmission bands (28, 30, 32) through the absorption layer 12. In an illustrative embodiment, the bandpass frequencies (28, 30, 32) comprise the three tristimulus frequencies, i.e., red (28), green (30) and blue (32) frequencies. The rugate layers (18, 20) include first (18) and second (20) rugate layers made of SiO.sub.2 and Ta.sub.2 O.sub.5, respectively.

Abstract: A thorium-free low absorption coating for infrared CO.sub.2 laser optics comprises an interior BaF.sub.2 layer formed on a substrate and an exterior layer formed over the interior layer to a predetermined thickness sufficient to substantially prevent water adsorption by the interior layer. Generally, the predetermined thickness is greater than about 11000 .ANG., and in one embodiment of a two-layer low absorption coating designed for antireflection at 10.6 microns, the exterior layer has a physical thickness in a range between about 24600 .ANG. and 22800 .ANG., and preferably about 24000 .ANG.. In the preferred two-layer AR coating embodiment, the exterior layer defines a cover layer and an absentee layer, and the interior layer is relatively thin. The preferred exterior layer and the preferred substrate consist essentially of ZnSe. Multilayer stacked coatings of more than two layer can also be formed to provide low absorption partially reflective or totally reflective coatings as well as AR coatings.

Abstract: A novel design for producing bandpass filters with essentially square shapes with little or no ripple in the passband zone. Filters are of the all-dielectric type consist of multiple cavities of bandpasses. Quarter wave thick layers of low index material separate all of the cavities from each other. Multiple half-waves may be added to the outer cavity quarter-wave stacks in particular. This invention provides the addition of half wave to some of the inner cavity stacks to remove ripple that would otherwise be present. Together, these additional half wave layers added to the outer and inner cavities sharpen the transition from low transmission to high transmission without unduly adding ripple to the high transmission zone.

Abstract: To provide a retroreflective material which has high utilization efficiency of light and which can give a reflected light to various color tones: the retroreflective material in accordance with the present invention, which comprises synthesizing an incident light by giving a phase contrast to a part of the incident light, and emphasizing a light component of specific wavelength region by interference and returning a colored light that the color tone is different from the incident light to the incident direction of the light, and to provide a hologram reconstructor which reflect the light to the almost the same direction as the incident direction, when the linear light that has regular directionality is irradiated, and which comprises graphic design function, decorating function and high forgery prevention property by using said retroreflective material as the hologram reconstructor: the retroreflective reconstructor in accordance with the present invention laminates said retroreflective material and a hologra

Abstract: A novel design for producing bandpass filters with essentially square shapes with little or no ripple in the passband zone. Filters are of the all-dielectric type that consist of multiple cavities of bandpasses with the first and last cavities consisting of four less layers than the inner cavities. The inner cavities are all identical. All of the cavities are separated from each other by quarter wave thick layers of low index material. Layers of low index material may be added between the filter and the entrance and exit mediums. The thickness of the first few layers and last few layers may be altered to enhance the transmission of the filter by matching the index structure of the passband to the adjacent mediums.

Abstract: A coated substrate including a substrate; a stack of coating layers provided on the substrate composed of, in the sequence recited, (i) a first layer of dielectric material which is a composite layer including a sub-layer comprising a selectively absorbent material having a refractive index of at least 1.4, a spectral absorption index k.sub..lambda. of at least 0.4 in the range 380<.lambda.<450 nm and having a ratio of k.sub.380<.lambda.<450 nm /k.sub.650<.lambda.760 nm >2, (ii) a first layer of a metal selected the group consisting of silver, gold, copper and alloys of one or more thereof, and (iii) a second layer of dielectric material.

Abstract: Anti-reflection (AR) coatings and coated articles are described. The thickness and composition of the coatings are determined by minimizing the product of the Fresnel reflection coefficients for a coating with the angular- and wavelength-dependent sensitivity of the human visual system to minimize the perceived reflectance for the coated article. A compact chamber is evacuated and flushed with chemically inert gas such as argon or nitrogen. One or more molecular precursors are deposited using plasma-enhanced chemical vapor deposition (PECVD) to form AR films. Single-layer AR coatings based on fluoropolymer films of controlled thickness, as well as organic, organosilicon, and/or inorganic multilayers are described.

Abstract: A light reflecting material having a reflecting layer comprising barium sulfate, titanium dioxide and a binder resin. When the light reflecting material of the present invention is used as a reflector of a lighting panel of edge light type, it efficiently causes light to enter into a light conducting plate and hence high brightness of the lighting panel can be obtained. High brightness is also obtained when it is used as a light reflecting material of backlight systems and illumination signboards.

Abstract: An organic substrate provided with a light absorptive antireflection film, which contains an organic substrate, and a light absorbing film and a low refractive index film formed in this order on the substrate, to reduce reflection of incident light from the low refractive index film side, wherein the organic substrate has its surface plasma-treated, and a layer made essentially of at least one member selected from the group consisting of silicon, a silicon nitride, a silicon oxide and a silicon oxy-nitride, is formed between the plasma-treated substrate surface and the light absorbing film.

Abstract: The invention relates to a low-pass optical filtering device for the UV band, comprising:a dielectric stacking (14) ensuring an anti-reflective function for .lambda.<.lambda..sub.c, where .lambda..sub.c is a so-called cutoff wavelength, of less than 300 nm, a metal base (12) ensuring a reflective function for .lambda.>.lambda..sub.c.

Abstract: An optical mirror comprised of a stack of film pairs of alternating layers f high and low indices of refraction materials is disclosed. The optical mirror may further comprise a non-polished substrate and provides the desired reflectivity for the use in the operation of a quantum well mirror that provides an optical bias for a ring laser gyroscope.

Abstract: A color filter plate includes a continuously-variable dichroic filter coating constituting a variable band-pass or variable band-reject filter having a spatially-modulated variable-density pattern formed in the coating, and provides continuously-variable hue and saturation characteristics along separate gradient axes. A color filter mechanism includes a sequential arrangement of rectangular or circular color filters, having continuously-variable band-pass or band-reject filter coatings, mounted in motorized carriages. One mechanism provides two-axis translation of the rectangular color filters while another mechanism provides translation and rotation of the circular color filters. A light projection system comprising a lamp with a reflector and a lens includes a color filter mechanism having sequential, continuously-variable band-pass and band-reject filters supported by motorized carriages mounted in a region where the beam diameter is small.

Abstract: A filter system for reflectively blocking laser radiation in the visible spectrum includes a multilayer interference structure arranged for reflectively blocking a continuous band of wavelengths including the laser radiation and transmitting other wavelengths in the visible spectrum. The filter system is arranged to control transmission of the other wavelengths of the visible spectrum such that the filter system has an essentially neutral transmission color and maximum photopic transmission consistent with the band of wavelengths reflectively blocked.

Abstract: A system of layers applied to a transparent substrate includes a first layer of an oxide such as ZnO or SnO.sub.2, a second layer of a substoichiometric oxide of Zn or Ta, a third layer of Ag or Cu, a fourth layer of a substoichiometric oxide of Ti, Cr, or Nb, and a fifth layer of similar composition as the first layer. The layers are preferably deposited by magnetron cathode sputtering in an atmosphere which consists of inert gas and, in the case of the oxide layers, a reactive gas.

Abstract: Anti-reflective coatings for use on an optical substrate are disclosed having a low reflectance over a broad band of wavelengths in the ultraviolet range and exhibiting excellent "laser durability." The anti-reflective coatings comprise a layer of high-refractive index material situated between at least two layers of low-refractive index material. The layers of high- and low-refractive index material are laminated onto an optical substrate, such as glass or quartz. The anti-reflective coating minimizes the loss of light due to flares, ghosts, etc. Additionally, reflections are reduced over a broad range of incidence angles.

Abstract: Apparatus is disclosed that provides a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis.

Abstract: An endoscope optical system is used in an endoscope which can be combined with at least two laser treatment units that produce different wavelengths. At least two filters for removing laser light are provided in the path of the optical system, and are arranged at positions where angles of incidence or emergence of a chief ray are different. In this way, even with the laser treatment units using a plurality of wavelengths, laser light of the plurality of wavelengths can be removed.

Abstract: The subject of the invention is a glazing assembly comprising at lest one transparent substrate provided with a stack of thin "A" layers composed in succession of a first coating of dielectric material, a first "functional" layer having reflection properties in the infrared, in particular a metallic layer, and a third coating of dielectric material. The sum of the thicknesses of the first and second functional layers is greater than or equal to 25 nm. The ratio of the thickness of the first functional layer to the thickness of the second functional layer is less than 0.55.

Abstract: In order to provide a multilayer film structure for soft X-ray optical elements in which a high reflectivity can be attained in even a soft X-ray wavelength region of a wavelength of 10 nm or less including the wavelength range of water window zone, in a multilayer film structure for soft X-ray optical elements wherein a first thin film, being a different type of a second thin film, and the second thin film are piled up in layers to form a multi-layer film, at least one of the aforesaid first thin film and the aforesaid second thin film is made to be an oxide thin film.

Abstract: This invention relates to an optical demultiplexor having a narrow band filter for separating a narrow band channel prior to utilizing one or more wide band filters for separating a plurality of channels into groups of channels. The groups of channels can then be further separated or demultiplexed by a plurality of narrow band filters. Advantageously, a plurality of closely spaced (i.e. 50 Ghz) channels can be separated using conventional dichroic filters.

Abstract: An optical article comprising a flexible plastic substrate having an index of refraction ranging from 1.55 to 1.71 and having first and second surfaces and an anti-reflection coating carried by the first surface. The anti-reflection coating consists of a high index material and a low index material in which the high index material has an index of refraction of 2.0 and greater to provide the index of refraction difference between the substrate and the high index material of 0.29 to 0.75. The low index material is formed of a material having an index of refraction of 1.38 or less to provide an index of refraction difference between the high index material to the low index material ranging from approximately 0.59 to 0.92.

Abstract: The UV blocking coating includes at least eight alternating layers of a first dielectric material and a second dielectric material stacked upon the surface of an optical substrate to thereby form windows, windscreens, lenses or the like. The first dielectric material has a higher index of refraction then the second dielectric material. For example, the first dielectric material can be TiO.sub.2, ZrO.sub.2 and Ta.sub.2 O.sub.5 and the second dielectric material can be MgF.sub.2 or SiO.sub.2. In addition, each layer of the second dielectric material has an optical thickness which is greater than the optical thickness of the underlying layer of the first dielectric material upon which the layer of the second dielectric material is stacked. As a result of the unique construction of the UV blocking coating, the reflectance of the UV blocking coating varies dramatically upon exposure to UV light on the one hand and to visible light on the other hand.

Abstract: A design for producing bandpass filters with passbands that are centered at the same wavelength for each mode of polarization. Filters are of the all-dielectric type that consist of single and multiple cavities of bandpasses. All of the layers are of the Quarter Wave type for ease of manufacture with the possible exception of the last few layers being modified to reduce reflection into a new media. The basic structure of the multi-layer bandpass filter is as follows: (XY).sup.n (YY)(XX).sup.m (YY)(YX).sup.n where n and m are integers and wherein X is one of a high refractive index layer and a low refractive index layer; and, wherein Y is the other of the high and low refractive index layer, X and Y being opposite indexes of refraction.

Abstract: An optical interference coating on a refractory substrate, the coating being comprised of alternating layers of silicon dioxide and zirconium dioxide. The coating can be in the form of an optical filter where a substrate bearing the coating can be repeatedly cycled between room temperature and a temperature of at least 1000 .degree. C without significant degradation of its optical or mechanical properties.

Abstract: A fluorescent yellow article containing a blend of an N,N'-disubstituted 3,4:9,10-perylenebis(dicarboximide) dye and a fluorescent yellow-green dye soluble in a polymeric matrix and meeting the chromaticity requirements of CIE and ASTM and having a fluorescence luminance factor of greater than 5, as well as a method of preparing such articles is described. Also described is a fluorescent retroreflective article containing a color layer having first and second sides, wherein the article includes retroreflective elements on one side of the color layer or a retroreflective base sheet disposed on one side of the color layer, where the color layer includes the above-mentioned fluorescent yellow article.

Abstract: An anti-reflection film comprises a transparent support and a low refractive index layer. The low refractive index layer has a refractive index of not higher than 1.45. The low refractive index layer comprises a binder polymer and micro polymer particles. The micro polymer particles are superposed upon each other to form micro voids surrounded by the particles. The micro polymer particles have a mean particle size in the range of 5 to 200 nm. According to the first embodiment of the present invention, the particles comprise a cross-linked polymer. According to the second embodiment of the present invention, the particles comprise a polymer cross-linked to the binder polymer.

Abstract: Two Fabry-Perot interference filters are used as tandum polarizers for a h-power laser beam counter measure in an optical scene. The scene radiation is directed on one polarizer; one plane of polarization of the laser beam is transmitted thereby and the other scene radiation is reflected to the other polarizer. The other polarizer transmits the other plane of polarization of the laser beam and reflects the other scene radiation to a photodetector, such as an image intensifier, infrared imager, television camera tube, or a human eye. The laser beam transmitted by the polarizers is trapped by absorbers and cannot harm the photodetector.

Abstract: An optical filter is provided for use in color projection display imaging systems which utilize liquid crystal light valves for image modulation. The optical filter is a dichroic coating which separates light into different colors. The optical filter is located on a light transmissive surface of a color splitting device such as a Philips prism. The optical filter is formed from layers of at least two different dielectric materials including a high refractive index material, such as zirconium oxide and a low refractive index material such as aluminum oxide. The low refractive index material has an average refractive index of no less than about 1.6. The high refractive index material has an average refractive index which is sufficiently greater than the average refractive index of the low refractive index such that the average refractive index of the high refractive index material divided by the average refractive index of the low refractive index material yields a ratio that is greater than about 1.

Abstract: A coating-substrate combination having high specular reflectivity at high temperatures reaching 800.degree. C. in a vacuum is described. The substrate comprises pure nickel metal or a nickel-containing metal alloy such as stainless steel having a highly polished reflective surface. The coating is a layer of silver deposited on the substrate to a thickness of 300 .ANG. to 3000 .ANG.. A 300 .ANG. to 5000 .ANG. protective coating of silica, alumina or magnesium fluoride is used to cover the silver and to protect it from oxidation. The combination is useful as a parabolic shaped secondary concentrator for collecting solar radiation for generating power or thermal energy for satellite uses. The reflective layer and protective coating preferably are applied to the reflective surface of the substrate by electron beam evaporation or by ion sputtering.

Abstract: An infrared energy reflecting enamel composition comprises a ground coat of enamel on a substrate and embedded TiO.sub.2 particles in the ground coat of enamel. The infrared reflecting enamel composition has an infrared energy reflectivity value of at least 80%. A method for manufacturing the composition is also disclosed for embedding the TiO.sub.2 in the enamel.

Abstract: A wideband quasi-optical millimeter-wave resonator achieves a wideband frency operation by using a variable dielectric constant photoconducting lens in a Fabry-Perot resonator. Changing the dielectric constant of the lens creates an associated change in the resonant frequency for a given axial mode.

Abstract: A glass article used for producing a coated, solar control glass for architectural windows. The coated article includes a glass substrate, a coating of a titanium oxide deposited on and adhering to the surface of the glass substrate, a coating of silicon dioxide deposited on and adhering to the surface of the coating of the titanium oxide, a second coating of titanium oxide deposited on and adhering to the surface of the coating of the silicon dioxide, and an outer coating of a conductive metal oxide deposited on and adhering to the surface of the second coating of the titanium oxide. A specific coating stack on the glass substrate provides a neutral colored article having a high visible light transmittance, a reduced solar energy transmittance, a low emittance, and a high total solar reflectance. The use of the article in architectural glazings results in a glazing that reflects solar energy in the summer and provides a low U value for the winter.

Abstract: The invention relates to a heat reflecting glass pane. This glass pane has a transparent glass plate and a multilayer coating formed on one side of the glass plate. The multilayer coating includes a first heat-reflecting layer formed on a surface of the glass plate, and a second layer formed on the first layer. The first layer has a first refractive index from 2.0 to 3.5, a first extinction coefficient from 0.2 to 1.5, and a first thickness from 20 to 80 nm. The second layer has a second refractive index from 1.6 to 2.3, a second extinction coefficient not higher than 0.03, and a second thickness from 10 to 100 nm. The second refractive index is smaller than the first refractive index. The heat reflecting glass pane does not so much reduce the reflectance of a visible light incident on the glass plate from the uncoated side, but substantially reduces the reflection of a visible light incident on the second layer from the coated side.

Abstract: The invention relates to a glass substrate having on at least one of its faces an antireflection coating formed by a stack of thin dielectric material layers having alternately high and low refractive indices. To prevent the modification of the optical properties of the coating in the case where the substrate is subject to a heat treatment such as tempering, bending or annealing, the layer or layers of the stack which are liable to deteriorate on contact with alkali ions such as sodium ions are separated form the substrate by at least one layer forming part of the antireflection coating and forming a "shield" with respect to the diffusion of alkali.

Abstract: The present invention relates to surfaces used to reflect light, and particularly to highly light reflectant surfaces that provide even diffusion of light for the purpose of maximizing light efficiency and/or uniformity in a luminaire. By employing an expanded polytetrafluoroethylene (PTFE) comprising a microstructure of polymeric nodes and fibrils, the material of the present invention demonstrates exceptional diffuse reflectivity across a wide spectrum of visible light. Additionally, the material of the present invention provides many properties that have been previously unavailable in highly diffuse reflective material, including a high degree of malleability, moldability and flexibility, and effective reflectivity even at relatively thin cross-sections.

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 and activation. The Ni--P layer has 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 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 an optical fibers or waveguides.

Abstract: Several techniques may be used for forming a colored interference filter coating on a substrate such as polyester film. The interference filter has two metal reflective films, at least one of which is semi-transparent. A layer of transparent acrylate polymer dielectric between the metal layers completes the interference filter, which may be sandwiched between protective layers. The dielectric is formed by evaporating an acrylate monomer having a molecular weight in the range of from 150 to 600. Preferably the acrylate monomer has a molecular weight to acrylate group ratio in the range of from 150 to 400. The acrylate condenses on the substrate and is polymerized in situ for forming a monolithic film with a sufficient thickness to produce an interference color. In several embodiments different areas of the film have different thicknesses for producing different interference colors.

Abstract: A zoom lens system includes, from the object to image side, a first lens unit of a positive refractive power having a first lens element with a power to both diffract and refract light. A second lens unit has a negative refractive power and may include a second lens element having both the power to diffract and refract light, and it least a third lens unit is included. A zooming operation is performed by varying the distances between the respective first, second, and third lens units.

Abstract: A process suitable for forming multi-layer (up to at least several hundred layers) monotonic/linear variable/wedge filter coatings on a single substrate surface and for forming monolithic filter assemblies which incorporate such filters, is disclosed along with the designs for such filters. The monolithic process uses radially variable filter fabrication techniques in combination with ion-assisted deposition to form stress controlled, radially variable filter coatings of the desired varied optical profile, preferably using high and low index materials stich as tantala and silica. Stress is minimized by balancing the amount of ion assist and the coating rate. Slices are cut radially from the substrate to form quasi-linear variable filters. Other coatings such as, but not limited to, a wide band hot mirror can be formed on the opposite surface of the substrate from the radially variable LVF method.

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.