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: A first layer containing a binder and fine particles having any one of tin oxide, indium oxide, zirconium oxide, and titanium oxide as a main component is formed at least on one surface of a base material formed of polyester in this order from a side of the base material. A second layer is disposed so as to be in contact with the first layer. Thereby, a multi-layer film is formed. When a refractive index of the base material is ?1, that of the first layer is ?2, and that of the second layer is ?3, a formula denoted by ?1<?2<?3 is satisfied. The multi-layer film has strong adhesive strength between layers, and exhibits excellent optical properties by efficiently preventing occurrence of rainbow unevenness due to interference of light on the interface. Further, the multi-layer film is used as a component of an image display device, thus ensuring excellent image quality.

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: 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: An optical tunable filter is provided including a first substrate having light transmission properties and having a movable part and a supporting member that movably supports the movable part and having a smaller thickness than the movable part, a second substrate having light transmission properties and opposed to the first substrate, a first gap and a second gap provided between the movable part and the second substrate, an interference part causing interference between the movable part and the second substrate through the second gap and a drive member changing an interval of the second gap by moving the movable part to the second substrate by making use of the first gap.

Abstract: The invention provides a dichroic mirror having a transmission characteristic in which a step due to splitting of P-polarized and S-polarized light can be reduced and having a fluorescence-transmitting band extending to long wavelengths. The invention also provides a fluorescence filter set that can be constructed of environmentally conscious glass materials that do no use harmful substances, such as lead, and a fluoroscopy apparatus including such a fluorescence filter set. The dichroic mirror comprises a transparent substrate and a dielectric multilayer film formed by alternately laminating high-refractive-index layers and low-refractive-index layers on the transparent substrate. The dielectric multilayer film includes from 50 to 150 alternately laminated high-refractive-index layers and low-refractive-index layers each having an optical film thickness from 1.5?0/4 to 2.

Abstract: A conductive anti-reflection coating has a surface quarterwave layer that is broken up into smaller portions by inserting one or more thin layers of conductive material in the dielectric material. The resulting stack of alternating layers of a dielectric material and an electrically conductive material provides a solid electrical contact to the buried conductive layer and exhibits a low surface contact resistance.

Abstract: An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.

Abstract: An anti-reflection coating is formed on an optical surface of an optical member for reducing the amount of light rays reflected from the optical surface. For light rays in a wavelength range from 400 nm to 700 nm, the anti-reflection coating has a reflectance of 0.5% or less if the light rays are incident on the optical surface at angles within a range from 0 to 25 degrees, and it has a reflectance of 3.5% or less if the light rays are incident at angles within a range from above 25 degrees to 60 degrees.

Abstract: Methods of fabricating large size, high performance multilayer diffraction gratings having a thick substrate that take advantage of reactive ion etching during the fabrication process are provided herein. In one implementation, a method of making a multilayer diffraction grating comprises the steps of: providing a substrate having a thickness of at least 2.0 cm; applying a dielectric structure having a plurality of layers on the substrate; depositing a photoresist; exposing the photoresist to a grating pattern; developing the photoresist to produce the grating pattern in the photoresist; and reactive ion etching to transfer the grating pattern to the dielectric structure. In preferred form, the substrate material of the grating is selected to have low electrical resistivity and high thermal conductivity.

Abstract: A projection screen and method of manufacturing provides clear images regardless of the brightness of the environment within which the projection screen is used. The projection screen includes an optical thin film comprised of a multilayer dielectric having alternating high reflectance layers for light in a particular wavelength and high transmittance for visible light except in particular wavelength ranges. The thickness of each of the dielectric multilayer is determined so that the optical thin film forms a band-pass filter.

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: An optical filter for screening out infrared and ultraviolet light includes a transparent substrate and a film stack formed on the substrate. The film stack includes a number of high refractive index layers and a number of low refractive index layers alternately stacked one on another. The film stack is represented as follows: (3.5H3.5L)7(2.5H2.5L)7(HL)6(0.76H0.76L)6, wherein, H represents a high refractive index layer having a base optical thickness equal to one fourth of a reference wavelength associated with the optical filter, L represents a low refractive index layer having a base optical thickness equal to one fourth of a reference wavelength associated with the optical filter, expressions enclosed in each parenthesis represent filter cavities, and superscripts represents the number of repetitions of the expression enclosed in that parenthesis.

Abstract: An optical device includes first and second laminated films of alternate layers of optical thin films of high refractivity material and low refractivity material, and having an optical film thicknesses of “a” and “b” respectively; wherein b>a, and an optical plate on which the first laminated film and the second laminated film are formed in sequence from at least one primary surface of the optical plate, wherein a third laminated film comprised of a lamination of optical thin films of high refractivity material and low refractivity material and having an optical film thickness “c” is interposed between the first laminated film and the second laminated film, wherein b>c>a. As a result, an optical device which has spectral characteristics where ripple in the opaque zone which blocks infrared light is suppressed, can be obtained.

Abstract: Provided is a Fabry-Perot type wavelength tunable optical filter, comprising a first mirror; a second mirror located over the first mirror; a driving body located over the first mirror, and having both ends fixed to the first mirror through a spacer; a plurality of electrodes, each formed on both ends of the driving body; a rod structure connecting a center of the driving body and the second mirror; a plurality of fixing means, each fixed to the first mirror at both sides of the rod structure through the spacer; and a plurality of elastic bodies connecting the rod structure with the plurality of fixing means and acting as a rotational axis. And the mirror is driven by the rod structure acting as a lever that has an elastic body as a rotational axis, when warping is generated by electro-thermal expansion, electromagnetic force or external force. Thereby the mirror can be driven in the larger wavelength tunable range and the low power consumption.

Abstract: An optical element has a structure in that a first mirror stack layer is formed on a substrate. A first transparent conductive film, a conductive buffer layer, a spacer layer having a primary or secondary electrooptic effect, a conductive buffer layer and a second transparent conductive film are stacked thereon in succession; and a second mirror stack layer is further formed thereon. A voltage is applied between the first and second transparent conductive films. The applied voltage change the refractive index of the spacer, changes a wavelength to be transmitted through or reflected from the layer.

Abstract: An optical substrate includes a transparent substrate; an interference spot-preventing layer composed of at least one sublayer, the interference spot-preventing layer being coated on the transparent substrate; and a hard coat layer disposed on the interference spot-preventing layer. In the optical substrate, when the complex refractive index of the hard coat layer at light of 550 nm is represented as nH?ik, nH is 1.45 to 1.59 and k is substantially zero. When the optical admittance of the interface between the interference spot-preventing layer and the hard coat layer is represented as (x+iy), x and y satisfy the formula of (x?nH)2+y2?0.08.

Abstract: A wavelength-tunable optical filter includes a stationary mirror, a movable mirror disposed so as to face the stationary mirror, an actuating plate for actuating the movable mirror, and a peripheral supporting portion holding the actuating plate which are disposed above a base layer. The movable mirror is displaced by applying a voltage between the electrodes provided on the actuating plate and the base layer, and the actuating plate is disposed between the movable mirror and the peripheral supporting portion so as to be displaced due to an electrostatic force.

Abstract: A reflector for extreme ultraviolet light, its manufacture method, a phase shift mask, an exposure apparatus and a semiconductor manufacture method, capable of making the wavelength dependency of a reflectance via a plurality of reflection surfaces be coincident with an center wavelength of exposure light and retaining a sufficient energy reaching a subject to be exposed. The reflector for exposure light to be used for exposure of a subject to be exposed in a lithography process of manufacturing a semiconductor device is configured to have a multi-layer film structure made by repetitively stacking a plurality of layers in the same order. The periodical length of the repetitive stack unit of the multi-layer film structure is set in such a manner that the center of full width at half maximum of the reflectance via a predetermined number of reflectors becomes coincident with the center wavelength of extreme ultraviolet light to be reflected (S102).

Abstract: Apparatus and methods relating to display stacks wherein one or more index matching layers are utilized to minimize reflectance at the boundaries of otherwise adjacent layers. More particularly, the present invention is directed to methods and apparatus relating to a multilayer display stack comprising a glass layer, a first index matching layer, a first intermediate layer, a second index matching layer, a second intermediate layer, and a light emitting display panel wherein: the glass layer, first index matching layer, first intermediate layer, second index matching layer, and second intermediate layer are each transparent or translucent, and comprise an index of refraction; the index of refraction of the first index matching layer is between the index of refraction of the glass layer and the first intermediate layer; and the index of refraction of the second index matching layer is between the index of refraction of the first intermediate layer and the second intermediate layer.

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: We theoretically introduce a new type of optical all-pass filter based on guided resonance in coupled photonic crystal slabs. The filter exhibits near-complete transmission for both on- and off-resonant frequencies and yet generates large resonant group delay. We further show that such a filter can be mechanically switched into a flat-top band rejection filter. We also show that a single photonic crystal slab can also function either as optical all-pass transmission or flattop reflection filter for normally incident light. Both filter functions are synthesized by designing the spectral properties of guided resonance in the slab. The structure is extremely compact along the vertical direction.

Abstract: High performance optical edge and notch filters and methods of making the same are disclosed. The multi-layer, thin-film optical edge filters have an edge steepness greater than about 0.8% as measured by dividing (a) the edge width from the 50% transmission wavelength to the optical density 6 (“OD6”) wavelength by (b) the 50% transmission wavelength. The optical edge filters also have an average transmission above about 95%. The notch filters exhibit a blocking of OD>6, very high transmission (>90%) outside the notch(es), and a narrow notch bandwidth comparable to that of holographic notch filters. The methods for making such filters accurately determine when deposition of each layer of the filter should terminate.

Abstract: High performance optical edge and laser-line filters and methods of making the same are disclosed. The optical edge filters have an edge steepness greater than about 0.8% as measured by dividing (a) the edge width from the 50% transmission wavelength to the optical density 6 (“OD6”) wavelength by (b) the 50% transmission wavelength. The optical edge filters also have an average transmission above about 95%. The laser-line filters have an extremely high transmission in the passband (greater than 90%), an extremely narrow transmission bandwidth, and achieve blocking with an optical density (OD) greater than 5 at wavelengths that differ from the laser wavelength by less than 1% of the laser wavelength. The methods for making such filters accurately determine when deposition of each layer of the filter should terminate.

Abstract: An antireflection film includes alternately deposited high-refractive-index layers and low-refractive-index layers. The refractive indexes and extinction coefficients of the layers are such that the antireflection film exhibits sufficient antireflection characteristics even if the geometrical thickness thereof is small. An optical element having the antireflection film on a substrate exhibits high transmittance and has excellent optical characteristics.

Abstract: The interferometric modulator of the invention includes a transparent substrate (refractive index: n0) 12, an optical thin film (complex index of refraction: N1=n1?i·k1) 13 provided on the transparent substrate 12, and an absorber layer (complex index of refraction: Ns=ns?i·ks) 14 opposed to the optical thin film 13, the distance of a gap to the optical thin film 13 being variable, wherein the relation n1>n0, k1?0 and ns>n0 is satisfied.

Abstract: This invention relates to a platform (11) and a method for generating electromagnetic field distributions. The invention relates in particular to optical sensors for measuring biological or chemical substances. The platform (11) according to the invention comprises a substrate (13), a structured layer (19) and, positioned between the substrate (13) and the structured layer (19), a multilayer assembly (17), said components being so matched relative to one another that upon appropriate impingement by electromagnetic radiation an electromagnetic field distribution is generated that is at a maximum within the structured layer (19).

Abstract: An optical tunable filter includes a first substrate 3 having a light transmitting property which includes a movable portion 31, a second substrate 20 having a light transmitting property which is provided so as to be opposed to the first substrate, a first gap 21 and a second gap 22 which are respectively provided between the movable portion 31 and the second substrate 20, an interference portion which causes interference of incident light between the movable portion 31 and the second substrate 20 through the second gap 22, and a driving portion which changes a distance of the second gap 22 by displacing the movable portion 31 with respect to the second substrate 20 using the first gap 21. This makes it possible to provide an optical tunable filter having a simpler structure and a smaller size, which can be manufactured through a simplified manufacturing process without using a release hole and can achieve stable driving of a movable portion, and a method for manufacturing such an optical tunable filter.

Abstract: A security element (1) for application or embedding in objects (300), in particular for documents of value such as bank notes, credit cards and the like, is structured in a multi-layer fashion and has an interference element I, which produces a color shift effect, a layer M with magnetic properties and a reflection layer R, which is located between interference element I and magnetic layer M. Designs of the invention pro-vide a negative writing 20 and/or coding 11 in reflection layer R and magnetic layer M. According to a further design diffraction structures 2 are integrated in the security element 1. Such a security element in particular is suitable as window security thread 200 in bank notes.

Abstract: Highly discriminating optical edge filters and methods of making the same are disclosed. The optical edge filters have an edge steepness greater than about 0.8% as measured by dividing (a) the edge width from the 50% transmission wavelength to the optical density 6 (“OD6”) wavelength by (b) the 50% transmission wavelength. The optical filters also have an average transmission above about 95%. The methods for making such filters accurately determine when deposition of each layer of the filter should terminate. The methods include calculating theoretical transmission data for a layer of the filter and calculating an expected deposition duration for the layer. The methods also include measuring transmission through the layer during deposition for a period less than the expected deposition duration.

Abstract: A projection optical system that projects a pattern on a first surface onto a second surface, and has a numerical aperture of 0.85 or higher includes an optical element, and an antireflection coating applied to the optical element, the antireflection coating including plural layers, an end layer having a refractive index of tan { sin?1(NA)} or greater, where NA is the numerical aperture of the projection optical system.

Abstract: An antireflection film includes alternately deposited high-refractive-index layers and low-refractive-index layers. The refractive indexes and extinction coefficients of the layers are such that the antireflection film exhibits sufficient antireflection characteristics even if the geometrical thickness thereof is small. An optical element having the antireflection film on a substrate exhibits high transmittance and has excellent optical characteristics.

Abstract: A wavefront modulating optical element device employs two or more materials lithographically patterned with programmed thickness profiles. The spatially-varying thickness profiles are chosen to yield arbitrary relative phase-shift and attenuation upon transmission. The device can be designed to create arbitrary diffractive optical elements with specific applications including diffusers, arbitrary holographic optical elements, null-elements for wavefront compensation and control in interferometry.

Abstract: A DWDM thin film filter includes a substrate (11) and a film stack (12). The film stack comprises a plurality of cavities (13). Each cavity includes a first group of mirror layers (21), a second group of mirror layers (22), and a spacer layer (23). Each group of mirror layers includes a plurality of high refractive index thin films (31) and low refractive index thin films (32) alternately deposited one on another. The material of the high refractive index films is a composition of indium-tin oxide. In the preferred embodiment, a thin film filter having 160 layers of film can be produced. Such a thin film filter attains the same or better optical characteristics as a conventional DWDM thin film filter having 180 layers of film.

Abstract: A multilayer interference reflecting film has individual optical layers arranged to form optical repeat units throughout the film. Each of a plurality of optical repeat units has six individual layers, at least three of which have different refractive indices at a design wavelength ?0. Individual layers having nominally the same refractive index and physical thickness, arbitrarily labeled “A”, “B”, “C”, and “D”, are arranged in a six-layer optical repeat unit in a cyclic permutation of CACDBD, where the A and B layers are each thicker than the C and D layers. The thicknesses and refractive indices of the individual layers can be selected to suppress the second, third, and fourth order reflections, while reflecting light at the design wavelength.

Abstract: An active type tunable wavelength optical filter having a Fabry-Perot structure is disclosed. A tunable wavelength optical filter which comprises a lower mirror in which silicon films and oxide films are sequentially laminated in a multi-layer and the silicon film is laminated on the highest portion; an upper mirror in which silicon films and oxide films are sequentially laminated in a multi-layer and the silicon film is laminated on the highest portion and which is spaced away from the lower mirror by a predetermined distance; a connecting means for connecting and supporting the lower mirror and the upper mirror to a semiconductor substrate; and electrode pads for controlling the gap between the lower mirror and the upper mirror by an electrostatic force and the method of manufacturing the same are provided.

Abstract: The optical device having a predetermined surface profile of the invention is fabricated by forming a multi-layered dielectric film on the surface of a solid composition layer having a glass transition temperature of not lower than 100° C. The solid composition layer is formed by molding and curing a polymerizable organic group-having fluid composition. The curing may be effected through photopolymerization or thermal polymerization of the polymerizable organic group in the composition, and a predetermined surface profile is transferred onto the composition layer from the mold used. The cured composition is released from the mold, and this is coated with a multi-layered dielectric film.

Abstract: The invention provides a multi-cavity filter, and in particular, a multi-cavity bandpass filter having a predetermined centre wavelength. The filter includes a plurality of cavities, each cavity including two partially reflecting films separated by a layer of dielectric material. The two partially reflecting layers are formed from layers of material having alternating high and low refractive indices. Each layer of dielectric material has a thickness that is an integral number of half-waves of the centre wavelength. The filter has an asymmetric structure that causes the reflected chromatic dispersion from one side of the filter to be reduced relative to the reflected chromatic dispersion from the other side.

Abstract: The present invention provides reflective films and other optical bodies which exhibit sharp bandedges on one or both sides of the main reflection bands. The optical bodies comprise multilayer stacks M1 and M2, each having first order reflections in a desired part of the spectrum and comprising optical repeating units R1 and R2, respectively. At least one of the optical repeating units R1 and R2 varies monotonically in optical thickness along the thickness of the associated multilayer stack.

Abstract: An optical shutter including a multi-layer fixed filter and a multi-layer movable filter arranged with a gap therebetween controls the transmittance of light passing through the multi-layer filters. The optical shutter includes minute driving elements provided on the movable filter. Operating the minute driving elements varies a distance of the gap defined between the fixed filter and the movable filter. Operation of the movable filter is restricted by a stopper that comes into contact with the movable filter when the gap has the maximum distance and by a bump formed on the fixed filter. The minute driving elements are joined to the movable filter with elastic bonding layers therebetween.

Abstract: The invention provides a tunable filter that can minimize adjacent channel cross talk despite an increase of a number of available wavelengths and quickly switch a wavelength to be used, and manufacturing method thereof, and also an optical switching device comprising such tunable filter. In a tunable filter having a Fabry-Perot etalon structure, not less than two cavity gaps 114 to 116 are provided and separation between the cavity gaps is controlled by any of electrostatic drive, electromagnetic drive or piezoelectric drive. In this case, the cavity gaps can be formed through the steps of forming a sacrificial layer in advance where a cavity gap is to be formed; forming a plurality of optical multilayer films 100 to 103; and removing the sacrificial layer by etching. Substrates 107 and 109 are combined through a supporting column 108.

Abstract: An antireflection film having a low reflectance and giving non-tinged reflected light with a low cost, which comprises: a transparent substrate; and a low-refractive layer having a lower refractive index than said transparent substrate, wherein the antireflection film has an average specular reflectance of 0.5% or less at an incidence angle of 5° in a wavelength region of from 450 to 650 nm, and, when CIE standard illuminant D65 in a wavelength region of from 380 to 780 nm is incident on the antireflection film at an incidence angle of 5°, the regular reflection light has a color having a* and b* values in a ranges specified by ?7?a*?7 and ?10*?b*?10 in the CIE 1976 L*a*b* color space.

Abstract: An optical security component for authenticating a document or a product including a transparent plastic film embossed to form an embossed surface and to have at least one diffraction grating; a layer of dielectric material of high optical index at least partially coated on the embossed surface and producing a colored effect of a first color for a first orientation of the component and a second different color for orientation perpendicular to the first orientation; a low optical index layer coated on a side opposite the viewing direction of the dielectric material; and a colored contrast layer having transparent zones and colored zones on the low optical index layer.

Abstract: An optical component of the present invention is compensated its optical dispersion, including third order dispersion, at low loss using optical dispersion compensating element comprising multi-layer film. In the optical component, an optical dispersion compensating element and a functional element are connected in series along an optical path.

Abstract: In accordance with an exemplary embodiment of the present invention, an optical apparatus includes a glass monolithic structure including a plurality of optical filter elements, and the glass monolithic structure is not an optical fiber. In accordance with another exemplary embodiment of the present invention, an optical apparatus includes a glass monolithic structure which includes a plurality of optical filter elements. The optical apparatus further includes a device which selectively aligns an optical input and an optical output to one of said plurality of optical filter elements. In accordance with another exemplary embodiment of the present invention, a method of adding/dropping a particular frequency from an optical signal includes providing a glass monolithic structure which further includes a plurality of optical filter elements. The method further includes providing a device which selectively aligns an optical input and an optical output to one of the plurality of optical filters.

Abstract: A reflector, a method of producing same and a method of creating high omnidirectional reflection for a predetermined range of frequencies of incident electromagnetic energy for any angle of incidence and any polarization. The reflector includes a structure with a surface and a refractive index variation along the direction perpendicular to the surface while remaining nearly uniform along the surface. The structure is configured such that i) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along the perpendicular direction of said surface, ii) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along a direction approximately 90° from the perpendicular direction of said surface, and iii) a range of frequencies exists which is common to both of said photonic band gaps. In an exemplary embodiment, the reflector is configured as a photonic crystal.

Abstract: A dielectric mirror including a substrate and a reflector portion disposed directly on the substrate. The reflector portion includes alternating layers, e.g. in excess of 150 alternating layers, of high and low index of refraction material. In one embodiment, the layers are configured for reflecting each wavelength in a bandwidth of 400 nm at greater than 97.5% reflectivity. In another embodiment, the layers are configured for reflecting an s-polarization and p-polarization of each wavelength in the range from 350 nm to 100 nm at greater than 98% reflectivity. High reflectivity is achieved for a wide range of angle of incidence.

Abstract: Optical bodies, comprising: a plurality of first optical layers comprising a first polymer composition that comprises (i) a polyester portion having terephthalate comonomer units and ethylene glycol comonomer units, and (ii) a second portion corresponding to a polymer having a glass transition temperature of at least about 130° C.; and a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers. Also disclosed are optical bodies comprising: (a) a plurality of first optical layers, each first optical layer being oriented; and (b) a plurality of second optical layers, disposed in a repeating sequence with the plurality of first optical layers, comprising a blend of polymethylmethacrylate and polyvinylidene fluoride. Methods of making the above-described optical bodies, and articles employing such optical bodies are also provided.

Abstract: This optical component includes a film formation substrate made of plastic, a magnesium fluoride film formed at an upper side of the film formation substrate and a first silicon oxide film formed on the magnesium fluoride film. The magnesium fluoride film may be formed on a surface of the film formation substrate. Alternatively, the optical component further may include a second silicon oxide film formed on a surface of the film formation substrate and between the film formation substrate and the magnesium fluoride film. The optical component can be realized, which is excellent in film adhesiveness, mechanical strength, drug resistance, environment resistance, and the like, as well as optical characteristics, and which is also excellent in productivity, film formation operability, cost, and the like.

Abstract: The invention provides a multi-cavity filter, and in particular, a multi-cavity bandpass filter having a predetermined centre wavelength. The filter includes a plurality of cavities, each cavity including two partially reflecting films separated by a layer of dielectric material. The two partially reflecting layers are formed from layers of material having alternating high and low refractive indices. Each layer of dielectric material has a thickness that is an integral number of half-waves of the centre wavelength. The filter has an asymmetric structure that causes the reflected chromatic dispersion from one side of the filter to be reduced relative to the reflected chromatic dispersion from the other side.