Abstract: In an absorption type multi-layer film ND filter having a thin substrate and provided thereon first and second absorption type multi-layer films which attenuate transmitted light, the first and second absorption type multi-layer films are constituted of multi-layer films each consisting essentially of dielectric layers formed of SiO2, Al2O3 or a mixture of these and metal film layers formed of Ni alone or an Ni alloy; the layers being alternately layered on the substrate; and the first and second absorption type multi-layer films are so formed on one side and the other side, respectively, of the substrate as to have a film structure in which they are symmetrical to each other interposing the substrate between them, and the warpage of the substrate has been controlled at a curvature of radius of 500 mm or more.

Abstract: An ultracompact, lightweight, reflective telescope is described which has no loss due to central obscuration for a beam being projected from its focus. The optical surfaces are composed of matched conics of rotation.

Abstract: There is disclosed an optical attenuator plate and an optical attenuator plate to adjust a quantity of light from a light source, which has a plurality of high-transmittance regions with a relatively high transmittance, and in which shapes of the high-transmittance regions are so defined that an intensity distribution of diverging light or converging light having passed through the optical attenuator plate becomes uniform.

Abstract: The present application disclosed various embodiments of improved durability broad band metallic neutral density optical filters and various methods for the manufacture thereof. The devices disclosed herein include a fully densified protective thin-film layer that is essentially 100% bulk devices, free of substantially all porosity, thereby providing full environmental protection of the underlying sensitive metallic filter layer and substrate. In one embodiment, the present application is directed to a neutral density filter and includes a substrate, at least one metallic filter layer having a thickness from about 10 nm to about 100 nm applied to the substrate, and at least one protective layer having a thickness of about 10 nm to about 100 nm applied to the filter layer using an ion-plating process.

Abstract: An optical device including a lens group which generates an optical image on an image pickup area by focusing an image of a photographing object, an optical diaphragm which narrows light flux optically when the optical portion generates the optical image, an ND filter group which is disposed in front of or behind the optical diaphragm and constituted of a plurality of ND filters each having a different light transmittance, and an ND filter adjusting portion which adjusts a positional relation of the ND filter with respect to the optical axis of the optical portion. At least one of the plural ND filters is an oblique ND filter in which the transmittance change line which is a change line of the light transmittance intersects at least two sides constituting the image pickup area obliquely.

Abstract: An absorption type multi-layer film ND filter having a substrate formed of a resin film and provided on at least one side thereof an absorption type multi-layer film formed of oxide dielectric film layers and absorption film layers which are alternately formed in layers, characterized in that the oxide dielectric film layers are each constituted of an SiCyOx (0<y?0.1, 1.5<x<2) film having an extinction coefficient at a wavelength of 550 nm of from 0.005 to 0.05, formed by a physical vapor deposition process making use of a film-forming material composed chiefly of SiC and Si, and the absorption film layers are each constituted of a metal film having a refractive index at a wavelength of 550 nm of from 1.5 to 3.0 and an extinction coefficient at that wavelength of from 1.5 to 4.0, formed by a physical vapor deposition process; an outermost layer of the absorption type multi-layer film being constituted of one oxide dielectric film layer formed of the SiCyOx film.

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 film coating method enables, when forming film layers in response to optical characteristics on a substrate, to coat gradation range layers of decreasing thickness without distributions, and to coat films on a plurality of substrates at the same time. The gradation range layer is formed by sputtering evaporation targets of dielectric substances with an introduction gas, followed by forming the films with compounds generated by applying a reactive gas to the films.

Abstract: This invention decreases a spectral reflectance in the entire visible wavelength range, to decrease inconveniences in an image such as flare or ghost. A non-reflective periodic layer including a large number of fine uneven periodic structure bodies is formed on a substrate, and an ND film is formed on the other surface of the substrate by vacuum deposition, to improve an anti-reflection function. Regarding a beam entering the ND filter, the MgF2 film of the formed ND film suppresses the spectral reflectance at the boundary of the atmosphere and the ND film and at the boundary of the ND film and the substrate. The non-reflective periodic layer decreases the reflectance at the boundary of the substrate and the atmosphere.

Abstract: A dimming system (300) for dimming electromagnetic radiation intensity of a radiating unit, such as e.g., an optical system. The dimming system (300) is adjusted to provide a constant electromagnetic radiation intensity over the cross-section of the impinging electromagnetic radiation beam by providing at least two dimming units (320, 330) each having a spatially variable position-dependent dimming behavior, such that the degree of dimming for the whole cross-section can be chosen to be a fixed selectable dimming factor. The dimming units (320, 330) may be based on spatially variable position-dependent dimming devices based on transparent substrates having a coating with a position-dependent varying transmission/reflection coefficient, on spatially variable position-dependent diffusing devices or on polarizer devices.

Abstract: An ND filter is composed of a transparent substrate, a laminate of a light-absorbing film and a dielectric film formed on the transparent substrate, and a carbon film formed to clad a surface of the laminate of the light-absorbing films and the dielectric films. Depending on cases, another carbon film is also formed on a reverse side of the transparent substrate. The carbon film is formed by a deposition process at a deposition temperature ranging from a room temperature to 150° C. The light-absorbing film is formed of a mixture of metal and compound thereof, a material of the metal being selected from a group consisting of Ti, Cr, Ni, NiCr, NiFe, and NiTi. The dielectric film is formed of SiO2 or Al2O3.

Abstract: The invention relates to an electronic imaging system such a video camera or digital camera, whose thickness or size is reduced while performance degradation is reduced as much as possible. The system comprises a zoom lens system comprising a first G1, a second G2, a third G3 and a fourth lens group G4 and an aperture stop S, and an electronic image pickup device located on its image side I and covered with a cover glass CG. The image of a subject is formed on the photoreceptive surface of the electronic image pickup device for conversion into electric signals. The system satisfies the following conditions (1) and (2). a?4 ?m??(1) F>a??(2) Here a is the horizontal pixel pitch in ?m of the electronic image pickup device and F is the F-number of the zoom lens system at its wide-angle end.

Abstract: The invention relates to a device for the IR-spectrometric analysis of a solid, liquid or gaseous medium. The device includes a process probe, which has a reflection element. The device additionally includes a linear variable filter, at least one detector element, and a control/evaluation unit. At least one light source is also provided, the light of which is coupled into the reflection element via a collimating optics. At least one optical waveguide having a light input section and a light output section is provided. The light is guided via the light output section of the optical waveguide into a defined region of the linear variable filter. The detector element and the linear variable filter are arranged movably relative to one another over approximately the length of the linear variable filter. The control/evaluation unit determines the spectrum of the medium on the basis of the measured values delivered from the detector element.

Abstract: A semiconductor structure includes a light emitting region disposed between an n-type region and a p-type region. A wavelength converting material configured to absorb a portion of the first light emitted by the light emitting region and emit second light is disposed in a path of the first light. A filter is disposed in a path of the first and second light. In some embodiments, the filter absorbs or reflects a fraction of first light at an intensity greater than a predetermined intensity. In some embodiments, the filter absorbs or reflects a portion of the second light. In some embodiments, a quantity of filter material is disposed in the path of the first and second light, then the CCT of the first and second light passing through the filter is detected. Filter material may be removed to correct the detected CCT to a predetermined CCT.

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: The present invention relates to an apparatus for reading from and/or writing to holographic storage media, and more specifically to an apparatus for reading from and/or writing to holographic storage media having an apodization filter. According to the invention, an apparatus for reading from and/or writing to a holographic storage medium, with a collinear split aperture arrangement of a reference beam and an object beam or a reconstructed object beam, includes an apodization filter for the reference beam.

Abstract: This invention decreases deformation of a plastic substrate caused by thermal expansion and contraction in an evaporation process of forming a multi-layered film of an ND filter, thus helping prevent wrinkles. The plastic substrate serving as the base of the ND filter is made of a polyimide-based plastic material having a glass transition temperature of 200° C. or more, has a total transmittance of light of 90% or more, and has a haze factor of 0.5% or less. As the multi-layered film, Al2O3 films for reduction of the reflectance and TiOx films for reduction of the transmittance are alternately formed on the substrate.

Abstract: A micro-optical element is produced through vapor deposition techniques, such as atomic layer deposition. An optical structure having a surface with uneven structures is exposed to one or more precursor vapors to create a self-limiting film growth on the surface of the optical structure. The film thickness may be increased and controlled by subsequent exposures. The resulting film conforms to surface structures having varying complex dimensions.

Abstract: Provided is an ND filter including an alternating layer which is composed of two films being alternately stacked and formed on a transparent substrate, the two films having different refractive indexes, wherein the alternating layer has a substrate-side reflected light attenuating multi-layered film and a transmittance adjusting multi-layered film formed on the transparent substrate in the stated order from the transparent substrate side, and the light absorption amount of the substrate-side reflected light attenuating multi-layered film is set to be 20% or more and 30% or less. Thus, an ND filter having satisfactory front surface reflection characteristics and rear surface reflection characteristics can be stably obtained while the transmittance of 4% or more and 11% or less is maintained with respect to the entire visible region (400 nm or more and 700 nm or less).

Abstract: This invention decreases deformation of a plastic substrate caused by thermal expansion and contraction in an evaporation process of forming a multi-layered film of an ND filter, thus arising of wrinkles is prevented. The plastic substrate serving as the base of the ND filter is made of a polyimide-based plastic material having a glass transition temperature of 200° C. or more, and has a total transmittance of light of 90% or more and has a haze factor, which represents the haze of 0.5% or less. As the multi-layered film, Al2O3 films for reduction of the reflectance and TiOx films for reduction of the transmittance are alternately formed on the substrate. An MgF2 film made of a low-refraction material is formed as the uppermost layer to further reduce the reflection. In the evaporation process, even when the temperature of the plastic substrate reaches almost 200° C.

Abstract: An absorption type multi-layer film ND filter having a substrate and an optical multi-layer member consisting essentially of metal layers each composed chiefly of nickel (Ni) and dielectric layers each formed of any one of SiO2, Al2O3 and a mixture of these; the layers being alternately layered on the substrate. An Ni type metallic material having a small wavelength dependence of transmittance in the visible spectral range is used in the metal layers serving as light attenuation layers, and this enables materialization of an ND filter which can attain transmittance attenuation that is flat for wavelengths.

Abstract: An ND filter is made of a transparent substrate having a plane. An optical film is formed on the plane of the transparent substrate. The optical film has a lamination structure including a light absorption film and a dielectric film, and has a variable transmission density. A thickness of either the light absorption film or the dielectric film of the lamination structure is changed in an in-plane direction of the transparent substrate so that the transmission density of the optical film is controlled to vary in the in-plane direction. The light absorption film is composed of a material selected from Ti, Cr, Ni, NiCr, NiFe, NiTi and a mixture thereof, and the dielectric film is formed of SiO2, Al2O3 or a compound thereof.

Abstract: A process for producing a light amount-adjusting member, such as an ND filter, that comprises the steps of providing a transparent base material and a coloring liquid; and applying a coloring liquid to the base material by ejecting the coloring liquid to the base material to form a colored portion having a specified optical density, wherein the coloring liquid contains at least one coloring material of with a maximum absorption wavelength in a range of 630 to 750 nm, when measured on the transparent base material.

Abstract: A monolithic optical pellicle and method of making used to protect a photomask during photolithography processing. The monolithic optical pellicle is comprised of a pellicle plate having a recessed central portion integrally formed with a perimeter frame of the pellicle plate such that it is a one-piece optical pellicle. The monolithic optical pellicle comprises a material of sufficient rigidity to minimize distortions in and maximize durability of the pellicle when used in combination with the recessed portion having a thickness that prevents sagging thereof due to applied forces on the resultant monolithic optical pellicle. This recessed central portion is the optical pellicle portion of the present monolithic optical pellicle, while the integral perimeter frame is used to attach the monolithic optical pellicle at the desired stand-off distance to a photomask. The monolithic optical pellicle preferably comprises a material that is transparent to an exposure field at about 157 nm wavelengths.

Abstract: To provide an ND filter and a light amount adjusting device, in which a deterioration of optical performance of an optical system is small, and in addition, an optical system having the light amount adjusting device, and an optical device having the optical system. More specifically, an ND filter according to the present invention includes: a base that transmits light having a predetermined wavelength ?; and a filter member selectively formed on the base, in which: a transmittance of the filter member gradually changes in a region in a predetermined direction; and a phase difference which is produced between light transmitting through the filter member and light transmitting through a region on the base in which the filter member is not formed is ?/5 or less in a boundary of the filter member.

Abstract: A method and an apparatus for regulating the brightness of a light source (2), configured as an incandescent lamp, in the illumination beam path (8) of a microscope (1), the brightness of the light source (2) being modifiable by increasing or reducing the electrical power delivered to the light source (2), are characterized in that a red shift, associated with the reduction in the delivered electrical power, of the spectrum of the light emitted by the light source (2) in the illumination beam path (8) is compensated for by way of a variable optical filter (16) that brings about a blue shift of the spectrum. A color-neutral regulation of the brightness of the illuminating light is thereby achieved.

Abstract: A lens barrel includes an optical system including a short focal length for a wide angle of view; and an ND filter in the shape of a disc which is provided on an optical axis of the optical system. An optical density of the ND filter decreases in a direction radially outwards from a center of the ND filter.

Abstract: An optical filter which can be manufactured at low cost and is excellent in optical characteristics is disclosed. The optical filter has a transparent substrate and a first layer which is formed on the surface of the transparent substrate. Here, the first layer has a first area which is substantially transparent and a second area which has colored ink and is light-amount adjustable, and the optical path lengths with respect to the first and the second areas are substantially equal.

Abstract: The device of the present invention includes an electrochromic element having a transmittance that varies in response to an electrical signal, a base substrate disposed in spaced relation to the electrochromic element, a seal disposed between the base substrate and the electrochromic element, and an optical sensor. The seal, base substrate, and electrochromic element form a sealed cavity therebetween, in which the optical sensor is disposed. According to another embodiment, an electrochromic device is provided that includes a first substrate, an electrochromic medium disposed on the first substrate, a pair of electrodes in contact with the electrochromic medium, a pair of conductive clips, each in electrical contact with a respective one of the electrodes, and two pairs of electrical lead posts for mounting the first substrate to the circuit board. Each pair of lead posts is attached to, and extends from, a respective one of the conductive clips.

Abstract: The present invention provides a method of manufacturing an ND filter having a gradation density distribution, the ND filter, and an aperture device and a camera having the ND filter. A structure thereof is as follows. The method of manufacturing an ND filter having at least two kinds of films on a substrate includes the steps of: forming a film of at least one layer other than an outermost layer having a gradation density distribution while rotating a slit mask integrally with the substrate; and forming a film of the outermost layer without using the slit mask.

Abstract: A pair of dual complementary optics having a first lens and a second lens wherein the first lens has a gradient of a multiplicity of bands, the uppermost series of bands having a primary color embedded therein and the lowermost series of bands having a complementary secondary color embedded therein, the second lens having the inverse color embedded therein so that a primary color in the first lens is aligned with a secondary color in the second lens and a secondary color in the first lens is aligned with a primary color in the second lens.

Abstract: A flexible medium for a scrolling color changer and method of making thereof. The medium is made by applying an ink using a Meyer Rod which has varying cell lengths along its length. This leaves varying size cells of ink at different locations along the length of the medium. The ink has special characteristics whereby its evaporation rate and viscosity are carefully controlled. The viscosity is such that an amount of levelling will occur will be equal to the distance between any cells, but that cell to cell levelling will not, in general, occur.

Abstract: The present application describes embodiments of a neutral density color wheel filter. According to one embodiment, a neutral density color wheel (100) includes an opaque coating (135) over one or more color segments (120, 130, 140, 150, 160, 170) with randomly placed transmissive regions (131). The transmissive regions (131) can be configured to substantially transmit incident light and the opaque coating (135) can be configured to substantially block or absorb the incident light. Alternatively, the transmissive regions (131) can be configured to substantially transmit the incident light. The color segments with opaque coating (135) and transmissive regions (131) substantially eliminate light recycling due to the reflection from the color wheel. The light transmission from the color wheel (100) is independent of the optics of a display system.

Abstract: There is disclosed a light amount adjustment apparatus for adjusting a state of a flux passed through an aperture having a predetermined aperture diameter, the apparatus comprising: a light amount adjustment member in which a first region having a predetermined transmittance to the flux and a second region for blocking the flux are disposed on the same base material. In the light amount adjustment apparatus, although an optical filter is integrally constituted with a diaphragm blade, there is little positional shift of an ND filter, a shape of the ND filter has a degree of freedom, deterioration of resolution of an image is improved for use in optical apparatuses such as a photographing apparatus, optical properties are superior, the whole apparatus can be miniaturized, and cost reduction of a product can be achieved.

Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposited film formed on a surface of the substrate. The plastic sheet has at least 120° C. of a glass transition temperature. In producing the ND filter, the deposited film is formed on the surface of the substrate at a temperature below the glass transition temperature of the plastic sheet to suppress deformation due to expansion and contraction and to prevent the plastic sheet from wrinkling.

Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposit film deposited on a surface of the substrate. The plastic sheet is composed of a norbornene resin and the deposit film is composed of a nickel-chromium alloy. The norbornene resin has a small thermal shrinkage factor and prevents the plastic sheet from wrinkling. The nickel-chromium alloy has a good oxidation resistance and ensures a uniform light transmittance of the deposit film over the entire visible light region.

Abstract: An electrical variable optical attenuator (10) of the present invention has a housing (1), a cover (2), an attenuating means (3), an optical module (4), an electrical driving element (5), an input fiber (87) and an output fiber (86). The attenuating means includes a carrier (30) having a guide groove (301) and an inner screw (302). A filter (32) is fixed on the carrier. The optical module includes a guide pole (41). The electrical driving element has a screw rod (552), which couples with the inner screw. The attenuating means is assembled inside the optical module with the guide pole being received in the guide groove to confine the direction of movement of the carrier along the screw rod, thus helping to avoid trembling of the filter when the screw rod is rotated.

Abstract: A color-separating apparatus for a liquid crystal projector of single panel type that is capable of improving light efficiency and color revival property. In the apparatus, a color filter has red, green and blue colors formed in a spiral shape. A reflective plate is opposed to the color filter to reflect an incident light reflected and emitted from the color filter into the color filter again. Accordingly, a color light is transmitted with no light loss.

Abstract: An optical attenuator (8) has a substrate (glass substrate) (1) and an optical attenuation film (2) that attenuates an input light with a predetermined optical attenuation factor, and the optical attenuation film (2) is disposed on a light input face (3) of the substrate (1). An angle defined by the light input face (3) and the light output face (4) of the substrate (1) is set to 0.15° to 0.5°. A protective film (5) for preventing the deterioration of the optical attenuation film (2) is formed on a surface of the optical attenuation film (2).

Abstract: The invention concerns with an exposure control mechanism for use in an image pickup apparatus in which a diaphragm aperture formed by a plurality of diaphragm blades moving straightforward in opposite directions is covered by an ND filter, and intends to prevent deterioration of image quality caused by diffraction even in an image pickup device having a small picture size and a short pixel pitch. The image pickup apparatus comprises an exposure control mechanism for adjusting the quantity of light flux entering a shooting lens system. The exposure control mechanism comprises a diaphragm made up of diaphragm blades movable on a plane perpendicular to an optical axis in opposite directions to define a diaphragm aperture, and an ND filter made up of at least two ND filter elements having different transmittances.

Abstract: A pair of dual complementary optics having a first lens and a second lens wherein the first lens has a gradient of a multiplicity of bands, the uppermost series of bands having a primary color embedded therein and the lowermost series of bands having a complementary secondary color embedded therein, the second lens having the inverse color embedded therein so that a primary color in the first lens is aligned with a secondary color in the second lens and a secondary color in the first lens is aligned with a primary color in the second lens. Each lens is darkest on top and lightest on the bottom. Each lens transmits more than 50% visible light in both wavelength ranges 440-550 nm and 550-750 nm.

Abstract: The present invention relates to a method of deposition of an absorbing material upon a plastic/glass substrate by vacuum coating at an angle of inclination between 5° to 30° and using a mask on the evaporation source to produce a graded film material and a method for the preparation of graded density absorbing film useful as an antiglare optical device for protecting the eyes by reducing the glare by absorbing the light intensity falling upon it in a non-uniform fashion.

Abstract: A neutral density filter has a multi-layer structure of thin films laminated on a substrate made of a transparent material. The multi-layer structure contains a transparent thin film composed of a dielectric material effective to transmit the incident light and a non-transparent thin film effective to absorb a part of the incident light. The non-transparent thin film is composed of a metal material which is deposited by vacuum evaporation. The non-transparent thin film contains an oxide of the metal material, which is generated during the vacuum evaporation by introducing a gas containing an oxygen while maintaining a vacuum degree in a range of 1×10−3Pa to 1×10−2Pa, and which is deposited concurrently with the metal material.

Abstract: The invention relates to polymer compositions which enable thermooptic control of signal attenuation in the ultraviolet, visible and near infrared (NIR) regions of the electromagnetic spectrum, and devices incorporating such compositions. The compositions are derived from polymer mixtures which exhibit a cloud point phase transition at a temperature in the range of a thermooptically controlled device such as a programmable waveguide attenuator, a programmable neutral density filter, or an optically absorbent switch. An especially preferred embodiment of the invention comprises a mixture of a high molecular weight chlorotrifluoroethylene fluid and a wax with an “ON-state” insertion loss of below 0.1 dB/cm and an extinction ratio of 22 dB/cm in the 1550 nm NIR telecommunication band.

Abstract: An optical attenuator for attenuating an incident optical beam comprises at least two attenuating devices, each having a polarization dependent attenuation characteristic with a preferred orientation. The attenuating devices are arranged in the optical beam in a way that the preferred orientations of the polarization dependent attenuation characteristics substantially compensate each other, at least partially in defined locations. At least one attenuating device provides an attenuation characteristic wherein the attenuation for the incoming light beam varies in a defined direction. The preferred orientation of the polarization dependent attenuation characteristic of the at least one attenuating device is substantially in the same direction as the varying attenuation characteristics or substantially perpendicular thereto.

Abstract: The invention adjusts the spectral characteristics of a light emitting diode (LEDs) by placing a filter in the LEDs light emission path. The filter is printed on the lens of the LED or printed on a cap that is later attached to the LED via ink jet printing or another printing method. The specific ink colors selected for the filter depend on the deviation of each LED from a specified tolerance. The filters create a high degree of color and intensity uniformity without requiring labor and cost-intensive binning.

Abstract: The invention relates to polymer compositions which enable thermooptic control of signal attenuation in the ultraviolet, visible and near infrared (NIR) regions of the electromagnetic spectrum, and devices incorporating such compositions. The compositions are derived from polymer mixtures which exhibit a cloud point phase transition at a temperature in the range of a thermooptically controlled device such as a programmable waveguide attenuator, a programmable neutral density filter, or an optically absorbent switch. An especially preferred embodiment of the invention comprises a mixture of a high molecular weight chlorotrifluoroethylene fluid and a wax with an “ON-state” insertion loss of below 0.1 dB/cm and an extinction ratio of 22 dB/cm in the 1550 nm NIR telecommunication band.

Abstract: A method and apparatus for variable optical attenuation is disclosed. A variable optical attenuator is provided having a housing. Within the housing, a filter is mounted on a drive shaft of a motor such that the drive shaft passes through a substantially center point of the filter. The filter has a monotonically increasing filter gradient that begins at a lower optical density and gradually increases in optical density in a diametrical pattern. An input optical fiber provides a light signal to be attenuated. The input optical fiber introduces the light signal, which passes through a first collimator, through the filter, through a second collimator, and to an output optical fiber which exits the housing. When activated, the motor rotates the drive shaft to position the filter to a desired attenuation position for attenuating the light signal.

Abstract: An optical device, for homogenising the lighting in an image plane, defined by a digital optical sensor wherein the optical device is formed of a block made of transparent homogenous filtering material, this block having a substantially uniform absorption coefficient for all the wavelengths of the visible optical spectrum which pass through it, and having a variable thickness suited to a determined absorption profile.

Abstract: A system and method for minimizing critical dimension errors on imaged wafers is described. After imaging and processing one or more wafers, the various critical dimensions are determined across the imaged exposure field and compared with the target critical dimensions to ascertain average critical dimension errors. The critical dimension error distribution across the field is modeled and the necessary exposure dose corrections are calculated to compensate the critical dimension errors. A pellicle is formed with light intensity modifying regions corresponding to the calculated local dose corrections. These regions alter the amount of light which is transmitted from a light source through a semiconductor mask onto the exposure fields of the wafers. As a consequence, the critical dimensions of the printed features are altered as well. The light intensity modifying region may be formed by depositing, such as by sputtering, particles which reflect or absorb light.