Abstract: Plasmon-enable devices such as ultra-small resonant devices produce electromagnetic radiation at frequencies in excess of microwave frequencies when induced to resonate by a passing electron beam. The resonant devices are surrounded by one or more depressed anodes to recover energy from the passing electron beam as/after the beam couples its energy into the ultra-small resonant devices.

Abstract: This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.

Abstract: A multilayer photonic structure may include a plurality of coating layers of high index dielectric material of index of refraction nH and a plurality of coating layers of low index dielectric material of index of refraction nL alternately arranged with a first coating layer and a last coating layer of the multi-layer photonic structure comprise low index material. An index-thickness of each coating layer of the multilayer photonic structure is different than every other coating layer of the multilayer photonic structure. The multilayer photonic structure has a first high reflectivity bandwidth, a second high reflectivity bandwidth and a low reflectivity bandwidth wherein the low reflectivity bandwidth is positioned between the first high reflectivity bandwidth and the second high reflectivity bandwidth.

Abstract: An optical filter is provided which includes a plurality of hard coating layers of alternating high and low refractive index provided on a substrate and has an associated first transmission band. The filter also includes at least one additional plurality of hard coating layers including high and low refractive index layers and Herpin equivalent layers sandwiched therebetween. The additional plurality of layers has an associated second transmission band that substantially coincides with the first transmission band, but provides additional blocking at wavelengths outside the first transmission band. Relatively wide transmission bands and high blocking over an extended range of wavelengths can be achieved such that the filter is suitable for use in multiphoton fluorescence systems.

Abstract: An antireflection film is disposed on a surface of an optical substrate, and consists of first to tenth layers to stacked sequentially from the opposite side to the optical substrate. The first layer, the fourth layer and the ninth layer are low-refractive index layers made of a low-refractive index material exhibiting a refractive index of 1.35 to 1.50 with respect to the d-line. The third layer, the fifth layer, the seventh layer and the tenth layer are intermediate-refractive index layers made of an intermediate-refractive index material exhibiting a refractive index of 1.55 to 1.85 with respect to the d-line. The second layer, the sixth layer and the eighth layer are high-refractive index layers made of a high-refractive index material exhibiting a refractive index that is in a range from 1.70 to 2.50 with respect to the d-line, and that is higher than the refractive index of the intermediate-refractive index material.

Abstract: To provide a dielectric multilayer filter, such as an IR cut filter and a red-reflective dichroic filter, that produces an effect of reducing incident-angle dependency and has a wide reflection band. A first dielectric multilayer film 30 is formed on the front surface of a transparent substrate 28, and a second dielectric multilayer film 32 is formed on the back surface of the transparent substrate 28. The width W1 of the reflection band of the first dielectric multilayer film 30 is set narrower than the width W2 of the reflection band of the second dielectric multilayer film 32. The half-value wavelength E2L of the shorter-wavelength-side edge of the reflection band of the second dielectric multilayer film 32 is set between the half-value wavelength E1L at the shorter-wavelength-side edge and the half-value wavelength E1H at the longer-wavelength-side edge of the reflection band of the first dielectric multilayer film 30.

Abstract: A multilayer film-coated substrate having the stress of the film relaxed by depositing a multilayer film comprising a metal oxide film and a silicon oxide film on a substrate at a high speed by a sputtering method using a conductive sputtering material, and a process for producing a multilayer film-coated substrate having such a low stress, are presented. A multilayer film-coated substrate comprising a substrate and at least a metal oxide film and a silicon oxide film laminated thereon repeatedly at least once, wherein at least one layer of said metal oxide film is a metal oxide film deposited by sputtering by using, as the target material, a metal oxide MOX which is deficient in oxygen than the stoichiometric composition, to have the oxygen deficiency resolved, and the stress of the multilayer film is from ?100 MPa to +100 MPa.

Abstract: A back-illuminated image sensor may include a substrate in which photodiodes are disposed; an insulating layer on a first surface of the substrate; an interconnection layer in the insulating layer; an anti-reflection layer between the substrate and the insulating layer; a plurality of color filters on a second surface of the substrate opposite to the first surface; and a microlens on the color filters. Because the anti-reflection layer may be between the substrate and an interlayer dielectric layer, the reflection rate of light that passes through the substrate and arrives at an interface between the substrate and the interlayer insulating layer may be reduced.

Abstract: The present invention relates to an optical article having anti-reflection properties and high thermal resistance, comprising a substrate having at least one main face coated with a multi-layer anti-reflection coating comprising a stack of at least one high refractive index layer and at least one low refractive index layer, wherein the ratio: R T = sum ? ? of ? ? the ? ? physical ? ? thicknesses ? ? of ? ? the low ? ? refractive ? ? index ? ? layers ? ? of ? ? the ? anti ? - ? reflection ? ? coating sum ? ? of ? ? the ? ? physical ? ? thicknesses ? ? of ? ? the high ? ? refractive ? ? index ? ? layers ? ? of ? ? the ? anti ? - ? reflection ? ? coating is higher than 2.1.

Abstract: A surgical microscopy system having an illumination system is provided. The illumination system comprises a xenon gas discharge lamp and a spectral filter which is optionally positionable into an illumination beam path of the surgical microscopy system and removable from the same. The spectral filter substantially exhibits, in a wavelength range between 400 nm and 700 nm, a transmission increasing from about 0.12 to 1 having a gradient between 0.025/nm and 0.0035/nm, in particular 0.00293/nm. Thus, the illumination system is enabled to provide light having two different spectral characteristics which is advantageous in particular for imaging structures in the human eye scattering to a different degree.

Abstract: The disclosure relates to a method and apparatus for providing switching optical filter. The switching optical filter provides several functionalities at the same time. For example, the filter can be used to remove photons of undesirable wavelength, such as ultraviolet or infrared, while simultaneously switching from and between one mode to another in order to accommodate changing ambient light conditions. In one embodiment, the disclosure relates to a method for forming an optical filter, the method comprising: forming a first electrode layer on a substrate; forming an ion conductor layer to at least partially cover the first electrode layer; forming an optically transparent layer over the ion conductor layer, the optically transparent layer preventing transmission of photons having a first wavelength while transmitting photons of a second wavelength; and forming a second electrode layer to at least partially cover the optically transparent layer.

Abstract: A reflective optical element (1) for radiation with a wavelength ? in the ultraviolet wavelength range comprises a reflective surface (6), and a dielectric multilayer system (4) formed on the reflective surface (6) which comprises at least two successive pairs of layers (5.i, 5.i+1), each pair of layers (5.1 to 5.N) consisting of a high refractive index layer (H1 to HN) alternating with a low refractive index layer (L1 to LN), wherein the optical thicknesses (Hi, Hi+1) of the high refractive index layers (Hi, Hi+1) and the optical thicknesses (Li, Li+1) of the low refractive index layers (Li, Li+1) of each adjacent pair of layers (5.i, 5.i+1) are different from each other.

Abstract: A CWDM filter includes a substrate and a multi-layer structure coated on one side of the substrate. The multi-layer structure has the construction of H(LH)24L(HL)3H(LH)34L(HL)3H(LH)44L(HL)4H(LH)34 L(HL)3H(LH)44L(HL)4H(LH)34L(HL)3H(LH)34L(HL)2HLH4LH/NS, wherein NS is the substrate, L is a low (refraction) index layer with a thickness of ?0/4, H is a high (refraction) index layer with a thickness of ?0/4, and ?0 is the center wavelength of the light transmitting through the CWDM filter.

Abstract: A wavelength separation film having a structure containing plural thin films laminated to each other including a first thin film containing a high refractive index material, a second thin film containing a low refractive index material, and a third thin film containing a material having an intermediate refractive index that intervenes between the refractive index of the high refractive index material and the refractive index of the low refractive index material, the high refractive index material being silicon, the low refractive index material being at least one selected from silicon oxide, magnesium fluoride and aluminum oxide, and the material having an intermediate refractive index being at least one selected from titanium oxide, tantalum oxide, niobium oxide, zirconium oxide, hafnium oxide and aluminum oxide.

Abstract: An optical filter for a display device placed in front of a display panel 1000 of the display device includes a first layer 310 which is formed at a first area A1 and has a first light blocking ratio. The amount of light transmitted through the first area A1 is smaller than the amount of light transmitted through an adjacent area to the first area A1 such that the first area A1 becomes distinguished to form a dark mark or the adjacent area becomes distinguished to form a bright mark. The optical filter further includes a second layer 320 which is formed at a second area A2 and has a second light blocking ratio lower than the first light blocking ratio. The amount of light transmitted through the first area A1 is smaller than the amount of light transmitted through the second area A2 such that the first area A1 becomes distinguished to form the dark mark or the second area becomes distinguished to form a bright mark.

Abstract: A terahertz band optical filter having a dielectric multilayer periodic structure in which a plurality of dielectric materials are periodically layered. Multi-cavity layers each having an optical path length of n times ?/2 (n is an integer greater than or equal to 1) and made of a low-refractive index medium are arranged. The cavity layers are coupled using a single-layer coupling layer having an optical path length ?/4 and made of a high-refractive index medium, thus forming a multi-cavity structure. Matching layers each including a high refractive index layer and a low refractive index layer each having an optical path length of ?/4 are disposed at either end of the multi-cavity structure.

Abstract: Now, according to the present invention, multiple band optical reflectors are provided that utilize a stack of metal and dielectric layers to create a reflection curve in the visible spectrum that has multiple peak intensities. Reflectors of the present invention comprise at least two dielectric layers that have differing thicknesses, with metal layers disposed therebetween. The use of metal layers in the present invention, as opposed to using alternating layers of dielectric materials, results in a reflector that is substantially thinner than a conventional two dielectric reflector.

Abstract: A light control sheet comprises at least a light diffusing film and a prism sheet, wherein the light diffusing film has a light diffusing surface on one side and a rough surface on the other side, the prism sheet has a prism surface on one side and a smooth surface on the other side, the smooth surface has a smooth layer comprising at least a comb polymer, and the rough surface of the light diffusing film and the smooth surface of the prism sheet face each other. A light control sheet comprises at least a light diffusing film and a prism sheet, wherein the light diffusing film has a light diffusing surface on one side and a smooth surface on the other side, the smooth surface has a smooth layer comprising at least a comb polymer, the prism sheet has a prism surface on one side and a rough surface on the other side, and the smooth surface of the light diffusing film and the rough surface of the prism sheet face each other.

Abstract: A folding mirror includes a substrate and a dielectric multilayered film formed on a surface of the substrate. The dielectric multilayered film includes a first period layer with a structure represented by a formula (0.58H1.16L0.58H)N1, a second period layer with a structure represented by a formula (0.8L1.6H0.8L)N2, and a third period layer with a structure represented by a formula (0.95L1.9H0.95L)N3, wherein, H represents a thickness of a high refractive index layer being set at ¼ of a reference wavelength associated with the film, and L represents a thickness of a low refractive index layer being set at ¼ of a reference wavelength associated with the film, all of the N1, N2, and N3 represent the numbers of repetitions of the structures, enclosed by the corresponding parentheses, forming the first period layer, the second period layer, and the third period layer respectively.

Abstract: A phase shifter includes at least one photonic crystal structure having alternating high and low index dielectric layers. At least two defect structures are positioned between said photonic crystal structures. The defect structure includes one or more nonlinear materials used to produce an index change, whose effect is amplified to produce a specified phase shift in the output signal of said phase shifter.

Abstract: A general method is disclosed of designing two-component dichroic short-pass filters operable for incidence angle distributions over the 0-30° range, and specific preferred embodiments are listed. The method is based on computer optimization algorithms for an N-layer design, specifically the N-dimensional conjugate-gradient minimization of a merit function based on difference from a target transmission spectrum, as well as subsequent cycles of needle synthesis for increasing N. A key feature of the method is the initial filter design, upon which the algorithm proceeds to iterate successive design candidates with smaller merit functions. This initial design, with high-index material H and low-index L, is (0.75 H, 0.5 L, 0.75 H)?m, denoting m (20-30) repetitions of a three-layer motif, giving rise to a filter with N=2m+1.

Abstract: Data of a barometric pressure that a barometric pressure sensor outputs, and data of an air volume that an air-volume sensor outputs are input into a system control circuit. The system control circuit is provided with a table storing portion. In the table storing portion, a control table is stored. The control table is formed of a plus supplied-voltage value to fan power set by a barometric pressure value and an air-volume value, and a warning instruction. In a case that the warning instruction is selected based on the barometric pressure value and the air-volume value, the system control circuit turns on a warning-use LED so as to inform a user that a filter is clogged.

Abstract: Provided are multi-component films useful as optical display filters. The optical display filters include a multi-layer stack that contains at least one organic layer. The filters have high visible light transmittance, low visible light reflection, and provide electromagnetic interference shielding.

Abstract: An optical filter is formed of a layer stack that includes metallic layers and dielectric layers, with at least one dielectric layer being defined by more than one zinc-based film. These zinc-based films have different percentages of zinc. The selections of the percentages are based upon the positions of the films within the dielectric layer. An unexpectedly low sheet resistance is available if the zinc-based film that immediately precedes forming a metallic layer has a percentage of zinc in the range of 80 percent to next to 100 percent. Process stabilization and manufacturing cost are provided by placing the percentage of the lower zinc-based film closer to 50 percent (25-75). Process stabilization is further enhanced by providing an indium-based film within the dielectric layer adjacent to the metallic layer.

Abstract: A light dispersion filter is composed of three or more optically transparent layers each having a value equal to the value of the product of the refractive index and thickness of the optically transparent layer and transmitted light, and a plurality of partially reflective layers arranged alternately with the optically transparent layers and having predetermined reflectivities. Alternatively, a light dispersion filter has a plurality of etalon resonators which are arranged in series such that the value of the product of the refractive index of air and the interval of the etalon resonators is equal to the value of the product of the refractive index and thickness of the optically transparent layers.

Abstract: A vacuum evaporation method for forming a multi-layer film filter on a plastic optical component and a multi-layer film filter optical image-capturing assembly with the plastic optical component, in which the multi-layer film filter generally refers to various filters produced by adopting the optical interference principle. During the evaporation operation, the evaporation time of each film is not more than four minutes, the distance between the evaporation source and the plastic optical assembly must be more than 100 centimeters, and the ion assisted deposition is performed when the high refraction film and low refraction film are alternately laminated one upon the other to form more than 40 layers of films. The optical image capture assembly with the plastic optical component can be used without additionally adopting a multilayer film filter, thus effectively reducing the volume and the cost.

Abstract: An ND filter of a thin film type is formed on a transparent substrate, such that a light-absorbing film and a dielectric film are laminated on the transparent substrate. The transparent substrate is formed of a resin film which can be fed at a constant speed. The light-absorbing film is deposited by sputtering a target material comprised of a metal or a mixture of a metal and a metal oxide onto the resin film traveling at the constant speed while using a mixture gas of oxygen, nitrogen, and argon as an ambient gas. Consequently, the light-absorbing film is composed of a mixture of the metal and metal compounds, and has an extinction coefficient of 0.3 or more in a visible wavelength range. Typically, the light-absorbing film is composed of 1% through 50% by weight of the metal, 30% or more by weight of saturated metal oxide, and residual components composed of the compounds of the metal containing lower oxide and nitride of the metal.

Abstract: A solid-state imaging device including a color filter having a filter characteristic more approaching to a human visual sensitivity is provided. The color filter including a group of dielectric layers has high-refractive-index-material films and low-refractive-index-material films, the high-refractive-index-material film and the low-refractive-index-material film being n films and (n?1) films, lo respectively, which are laminated alternately, n being an integer equal to or larger than 4. The color filter includes at least a red-transmission filter, a green-transmission filter, and a blue-transmission filter. The group of dielectric layers is common in the color filter and includes two of the high-refractive-index-material films and one of the low-refractive-index-material films positioned between and in contact with the two of high-refractive-index-material films.

Abstract: A multi-layer mirror includes on top of the multi-layer mirror a spectral purity enhancement layer, for example for application in an EUV lithographic apparatus. This spectral purity enhancement layer includes a first spectral purity enhancement layer, but between the multi-layer mirror and first spectral purity enhancement layer there may optionally be an intermediate layer or a second spectral purity enhancement layer and intermediate layer. Hence, multi-layer mirrors with the following configurations are possible: multi-layer mirror/first spectral purity enhancement layer; multi-layer mirror/intermediate layer/first spectral purity enhancement layer; and multi-layer mirror/second spectral purity enhancement layer/intermediate layer/first spectral purity enhancement layer. The spectral purity of normal incidence radiation may be enhanced, such that DUV radiation is diminished relatively stronger than EUV radiation.

Abstract: An exemplary optical filter includes a substrate, a plurality of contiguous identical lower filter cavities formed on the substrate, and a plurality of contiguous upper filter cavities formed on the lower filter cavities. Each of the lower filter cavities includes two high refractive index layers and one low refractive index layer sandwiched between the high refractive index layers. Each of the upper filter cavities includes two low refractive index layers and one high refractive index layer sandwiched between the low refractive index layers. The plurality of upper filter cavities includes a first filter cavity, a plurality of second filter cavities, a third filter cavity, and a plurality of fourth filter cavities.

Abstract: A polarizer (2) for a liquid crystal display device includes a polarizer base (21), a first protective layer (20) and a second protective layer (22) on two sides of the polarizer base for protecting the polarizer base, and an anti-reflection layer (25) on the first protective layer. The anti-reflection layer includes a first layer (26), a second layer (27), a third layer (28) and a fourth layer (29) stacked in order. The anti-reflection layer of the polarizer can reduce the reflection of the light irradiated on the polarizer, and the loss of light can be reduced and higher light transmission rate can be achieved.

Abstract: A reflective filter including a substrate and an optical film structure disposed on the substrate is provided. The optical film structure includes a reflective layer, a spacing layer, a transflective layer and a transparent layer in sequence. Depending on the reflection and interference phenomenon form the layers of the optical film structure, a colored light within narrow band could be filtered by the reflective filter in order to enhance the color saturation of an image.

Abstract: A terahertz band optical filter having a dielectric multilayer periodic structure in which a plurality of dielectric materials are periodically layered. Multi-cavity layers each having an optical path length of n times ?/2 (n is an integer greater than or equal to 1) and made of a low-refractive index medium are arranged. The cavity layers are coupled using a single-layer coupling layer having an optical path length ?/4 and made of a high-refractive index medium, thus forming a multi-cavity structure. Matching layers each including a high refractive index layer and a low refractive index layer each having an optical path length of ?/4 are disposed at either end of the multi-cavity structure.

Abstract: A sensing method and apparatus using photonic band gap multilayered material. Photonic band gap multi-layers are formed from alternating layers of higher refractive index and lower refractive index materials, and may be deposited or disposed on a optically transparent substrate or a reflecting face of a prism. Light is directed into the prism, directed to the photonic band gap multilayer, and reflected out of the prism, where it is captured and analyzed. Various sensor configurations keep light wavelength or coupling angle fixed, while monitoring the change in the other parameter. Also disclosed is a microarray configuration with an array of probe spots placed on one surface of the multilayer, which is mounted on an x-y translation stage.

Abstract: An optical filter has a multilayer thin film comprising first to i-th layers stacked in alternate layers of high and low refractive indices on a transparent substrate. Respective odd-numbered layers (Sigh refractive index layers) and respective even-numbered layers (low refractive index layers) form repetitive sequences of layers each of which cyclically changes in optical thickness throughout the multilayer tin film. Each of k-th from-the-bottom alternate layers of high and low refractive indices has such an optical thicknesses as meet the following conditional expressions (1) and (2), concurrently: n×d=(.c/4)×[1+sin{(k?1)×}×.] ??(1) 0 . . . <1 ??(2) where .c is the center wavelength of reflection band, n is the ref ion index of the layer for the d-line, d is the physical thickness of the layer, . is a factor of a pitch angle represented by 2./the number of layers a one layer-stack, . is the rate of amplitude.

Abstract: The present invention features a fiber optic imaging system for generating a customized spectral response comprising (a) an optional optical source for generating optical energy, (b) an optical system for focusing multi spectral optical energy to form a focal surface; (b) a fiber optic element for conveying the optical energy, wherein the fiber optic element has an input end optically coupled to the focal surface to receive the optical energy and an output end to transmit the conveyed optical energy; and (c) a spectral filter optically coupled to at least one of the input and output ends of the fiber optic element, wherein the spectral filter has a filter passband configured to provide the fiber optic element with a pre-determined wavelength transmittance capacity, such that only pre-determined wavelengths of the optical energy are transmitted through the output end, thus achieving a customized spectral response.

Abstract: A thin film type ND filter being inexpensive and excelling in durability. There is provided ND filter (0) comprising transparent substrate (1) and, superimposed thereon, light absorption films (3,5) and dielectric films (2,4,6), wherein the light absorption films 3.5 consist of a composition comprising 1 to 30 wt. % of a metal in pure form and 50 wt. % or more of a saturated oxide of the metal with the balance of compounds of the metal containing lower oxides of the metal. Metal raw material of the light absorption films (3,5) is selected from among Ti, Cr, Ni, NiCr, NiFe and NiTi. As for the dielectric films (2,4,6), SiO2 or Al2O3 is used. Function of reflection prevention is imparted by superimposing the light absorption films (3,5) and dielectric films (2,4,6) in predetermined film thicknesses and in predetermined sequence. Alternatively, a reflection prevention layer may be formed on the back of the substrate (1).

Abstract: In an optical filter, a thin film is formed by laminating low refractive index layers alternatingly from a substrate side with high refractive index layers. The thin film is provided with first, second, and third laminated portions. In the first laminated portion, the refractive indices of the high refractive index layers become gradually higher. In the second laminated portion, the refractive indices of the high refractive index layers are substantially equal to the highest refractive index of the high refractive index layers constituting the first laminated portion. In the third laminated portion, the refractive indices of the high refractive index layers become gradually lower, and the refractive indices of the low refractive index layers are substantially equal to the lowest refractive index of the low refractive index layers constituting the second laminated portion.

Abstract: A projector incorporating a prism and a plurality of light valves for modulating light that passes though the prism, wherein the color splitting-converging prism includes a dichroic coating having multiple layers of high and low index of refraction and ¼ wavelength thickness at each desired angle of incidence for reducing dichroic shift and thereby minimizing light loss.

Abstract: Provided are a highly transmissive optical thin film having an improved structure, in which, optical reflection (due to a difference in the refractive index between a semiconductor material and the air, when light is extracted from a semiconductor light emitting device into the air) may be suppressed, an optical output loss may be reduced and light transmittance efficiency may be maximized or increased, a semiconductor light emitting device having the same, and methods of fabricating the same.

Abstract: An infrared (IR) light absorbing reflector is formed with a substrate that supports a first IR absorptive multilayer part having multiple layers of partial IR absorbing thin films. The first IR absorptive multi-layer part supports a second visible light reflecting multilayer part.

Abstract: An optical interference filter whose major component is a film member. The film member includes a plurality of window regions arranged discretely in a surface direction selectively transmit, using an effect of optical interference, light having a waveband that substantially belongs to a visible spectrum, the plurality of window regions being arranged discretely in the surface direction, and one or more boundary regions selectively transmit, using the effect of the optical interference, light having a waveband that substantially belongs to an invisible spectrum excluding the visible spectrum, the one or more the boundary regions being located between adjacent window regions.

Abstract: In an imaging optical system, which comprises a plurality of optical members and an aperture diaphragm, an anti-reflection coating is provided selectively on one or more surfaces of light-transmitting members that are concave with respect to the aperture diaphragm. The anti-reflection coating includes at least one layer made by a sol-gel method.

Abstract: An optical filter is provided which includes a plurality of hard coating layers of alternating high and low refractive index provided on a substrate and has an associated first transmission band. The filter also includes at least one additional plurality of hard coating layers including high and low refractive index layers and Herpin equivalent layers sandwiched therebetween. The additional plurality of layers has an associated second transmission band that substantially coincides with the first transmission band, but provides additional blocking at wavelengths outside the first transmission band. Relatively wide transmission bands and high blocking over an extended range of wavelengths can be achieved such that the filter is suitable for use in multiphoton fluorescence systems.

Abstract: In an optical filter, a thin film is formed by laminating low refractive index layers alternatingly from a substrate side with high refractive index layers. The thin film is provided with first, second, and third laminated portions. In the first laminated portion, the refractive indices of the high refractive index layers become gradually higher. In the second laminated portion, the refractive indices of the high refractive index layers are substantially equal to the highest refractive index of the high refractive index layers constituting the first laminated portion. In the third laminated portion, the refractive indices of the high refractive index layers become gradually lower, and the refractive indices of the low refractive index layers are substantially equal to the lowest refractive index of the low refractive index layers constituting the second laminated portion.

Abstract: An optical device includes a first optical member and a second optical member formed of a medium having a refractive index greater than 1, and a multiple layer film section. The multiple layer film section has a structure in which at least two types of thin film layers namely a first thin film layer and a second thin film layer which has a refractive index higher than a refractive index of the first thin film layer, are stacked alternately. The first optical member and the second optical member are joined by an adhering means (an adhesive), and satisfy a predetermined condition. At the multiple layer film section, from a light incident, a light in a first wavelength band is let to be reflected, and a light in a second wavelength band which is shorter than the first wavelength band, and a light in a third wavelength band which is longer than the first wavelength band is let to pass (to be transmitted).

Abstract: Now, according to the present invention, dichroic filters are provided that incorporate a flexible polymer film substrate, such as poly(ethylene naphthalate), onto which a dielectric and/or reflective metal stack has been formed. Filters of the present invention are durable, flexible, and lightweight, and can be advantageously used in many specialty lighting applications.

Abstract: A CWDM filter having four channels of the present invention comprises a substrate and odd number of stack structures. Each stack structure includes a first multi-layer stack, a spacer layer, a second multi-layer stack and a coupling layer arranged in turn from the side thereof approaching the substrate. The rules of the coupling layer of the No. [(N+1)/2?1] stack structure and the coupling layer of the No. [(N+1)/2+1] stack structure both are (2n+1)L, among which, n being a positive whole number, L representing for a low refraction index layer with a thickness of ?0/4 and ?0 representing for the center wavelength thereof. While the coupling layers of the other stack structures can be expressed as L.

Abstract: In an optical filter, a thin film is formed by laminating low refractive index layers alternatingly from a substrate side with high refractive index layers. The thin film is provided with first, second, and third laminated portions. In the first laminated portion, the refractive indices of the high refractive index layers become gradually higher. In the second laminated portion, the refractive indices of the high refractive index layers are substantially equal to the highest refractive index of the high refractive index layers constituting the first laminated portion. In the third laminated portion, the refractive indices of the high refractive index layers become gradually lower, and the refractive indices of the low refractive index layers are substantially equal to the lowest refractive index of the low refractive index layers constituting the second laminated portion.

Abstract: In an anti-reflective film including alternating layers of high refractive-index layers and low refractive-index layers, by designing such that a designed central wavelength ?0 is within a wavelength range of 141 nm to 189 nm, and that when the first to eighth layers as counted from a substrate have optical film thicknesses d1 to d8 respectively, the equations of: 0.45?0?d1?0.65?0; 0.05?0?d2?0.20?0; 0.29?0?d3?0.49?0; 0.01?0?d4?0.15?0; 0.05?0?d5?0.20?0; 0.23?0?d6?0.28?0; 0.23?0?d7?0.28?0; and 0.23?0?d8?0.28?0 are satisfied, the anti-reflective film can be formed so as to have a low reflectance for a light incident at such a large angle as 30 degrees or more, without increasing the whole thickness of the film.