Abstract: A mirror serves for use for guiding illumination and imaging light in EUV projection lithography. The mirror has a reflective surface, the reflective surface forming a magnetic field in such a way that at least one polarization property of the illumination and imaging light is influenced via the magnetic field upon reflection. A mirror system has, besides the mirror, additionally a magnetization predefining device for predefining a magnetization of the reflective surface of the mirror. An illumination optical unit has at least one mirror of this type or at least one facet mirror device comprising at least one individual mirror constructed in this way. In the case of a mirror of this type, the illumination and/or imaging properties of illumination and/or imaging light guided via the mirror are improved.

Abstract: A field facet mirror for an illumination optics of a projection exposure apparatus for EUV microlithography transmits a structure of an object arranged in an object field into an image field. The field facet mirror has a plurality of field facets with reflection surfaces. The arrangement of the field facets next to one another spans a base plane. Projections of the reflection surfaces of at least two of the field facets onto the base plane differ with respect to at least one of the following parameters: size, shape, orientation. A field facet mirror results which can ensure a uniform object field illumination with a simultaneously high EUV throughput.

Abstract: An optical element having an antireflection effect includes an incident plane and an emission plane and a conical microstructure formed on at least one plane of the incident plane and the emission plane. The conical microstructure includes a first structure formed of a plurality of conical microprojections with an average height H1 and a second structure formed of a plurality of conical microrecesses with an average height H2. The average height H1 satisfies an inequality H1?1/3*?/n and the average height H2 satisfies an inequality H2?1/3*?/n. An average pitch P between the first structure and the second structure satisfies following conditions: H1/2?P?1/3*?/n, and H2/2?P?1/3*?/n, in which the use wavelength is defined as X and the refractive index relative to the use wavelength is n.

Abstract: An optical module includes a chamber capable of being evacuated and a mirror in the chamber. The mirror includes a plurality of individual mirrors. Each individual mirror includes: a mirror body including a reflection face; a support structure; and a thermally conductive portion that mechanically connects the support structure to the mirror body. For at least one individual mirror, the thermally conductive portion includes a plurality of thermally conductive strips arranged radially, adjacent thermally conductive strips being separated from each other, and each of the plurality of thermally conductive strips connecting the mirror body to the support structure. For at least one individual mirror, an actuator is associated with the mirror body, the actuator being configured to displace the mirror body relative to the support structure in at least one degree of freedom.

Abstract: In order to make possible both good laser resistance and good antireflection properties, an optical element, in particular for UV lithography, comprising a substrate and a coating on the substrate having at least four layers, is proposed, wherein a first layer comprising a low refractive index inorganic fluoride compound is arranged on the substrate, a layer comprising an inorganic oxide-containing compound is arranged as a layer the most distant from the substrate, and at least two further layers each comprising an inorganic fluoride compound or an inorganic oxide-containing compound are arranged alternately between the first and the most distant layers.

Abstract: An infrared-transmitting film which is excellent in mechanical strength and environmental resistance. The infrared-transmitting film comprises a buffer layer formed on a surface of an infrared optical substrate and having a Vickers hardness greater than that of the substrate and an environmental resistance improving layer provided in contact with the buffer layer and having a Vickers hardness greater than that of the buffer layer.

Abstract: A UVB-visible hybrid system and method for visualizing a scene comprising one of more terrestrial corona discharge(s) and one or more objects is disclosed. On the UVB channel, an object-devoid UVB image of at least a portion of the scene is generated using UVB light which passes though a corona-peak tuned optical filter configured to filter out sufficient non-terrestrial-corona light so that the generated UVB image is object-devoid. The object-devoid UVB image is analyzed to classify pixels thereof as corona-discharge pixels or non-corona-discharge pixels. When a derivative of the object-devoid UVB image superposed with a visible-band image of the scene is displayed on a display device, the pixels classified as corona-discharge are displayed at increased visibility, while the pixels classified as corona-discharge are displayed at decreased visibility. In some embodiments, the optical filter has an average optical density over the [290 nm, 700 nm] spectrum of at least 4.

Abstract: An optical sensor is provided with reduced sensitivity toward external light influences, fluorophores, and radiation, more particularly gamma radiation. The sensor is suitable for determining at least one parameter in a medium. The sensor has a matrix that contains a fluorescent dye. The matrix is supported by a transparent substrate and has a precious metal layer on the side facing the medium. The precious metal layer provides protection against photobleaching and radiation. The optical sensor is suitable for implementation in containers and laboratory products that are sterilized by gamma radiation, such as disposable bioreactors.

Abstract: A method for determining the absorption of a blank (2) for producing an optical element (3), including: radiating a heating light ray (8) through the blank (2) for the purpose of heating the blank (2), and determining the absorption in the blank (2) by measuring at least one property of a measurement light ray (10) influenced by the heating of the blank (2). In the method, either the heating light ray (8) and the measurement light ray (10) or the heating light ray and a further heating light ray are oriented to enter into the blank (2) through a first polished surface (2a) or a second polished surface (2b), situated opposite the first surface, and meet one another exclusively in the interior of the blank (2), preferably in a volume (12) used for the production of the optical element (3). An associated measuring apparatus (1), optical element (3), and optical arrangement are also disclosed.

Abstract: A variable transmission medium having a plurality of patterned surfaces disposed on light-transmissive material and separated by an inter-surface gap enabling regulation of light transmission by a change in angle of incident or viewing.

Abstract: An imaging catoptric optical unit has at least four mirror, which image an object field in an object plane into an image field in an image plane. A first chief ray plane of the optical unit is prescribed by propagation of a chief ray of a central object field point during the reflection at one of the mirrors. A second chief ray plane of the optical unit is prescribed by propagation of the chief ray of the central object field point during the reflection at one of the other mirrors. The two chief ray planes include an angle that differs from 0. In an alternative or additional aspect, the imaging optical unit, considered via the image field, has a maximum diattenuation of 10% or a diattenuation that prefers a tangential polarization of the imaging light for a respectively considered illumination angle. The result of both aspects is an imaging optical unit in which bothersome polarization influences are reduced during the reflection of imaging light at the mirrors of the imaging optical unit.

Abstract: A method of manufacturing a sub-wavelength extreme ultraviolet metal transmission grating is disclosed. In one aspect, the method comprises forming a silicon nitride self-supporting film window on a back surface of a silicon-based substrate having both surfaces polished, then spin-coating a silicon nitride film on a front surface of the substrate with an electron beam resist HSQ. Then, performing electron beam direct writing exposure on the HSQ, developing and fixing to form a plurality of grating line patterns and a ring pattern surrounding the grating line patterns. Then depositing a chrome material on the front surface of the substrate through magnetron sputtering. Then, removing the chrome material inside the ring pattern. Then, growing a gold material on the front surface of the substrate through atomic layer deposition.

Abstract: An apparatus for focusing light in a semi-conductor inspection system, including: a first mirror arranged to reflect extreme ultra-violet (EUV) generated by a plasma source; and a second mirror arranged to focus the EUV light, reflected from the first mirror, onto a first intermediate focus plane. A homogenizing tunnel, including: a first aperture having a first shape and a first size and arranged to receive extreme ultra-violet (EUV) light; a second aperture having a second shape and a second size; and a passageway connecting the first and second apertures and arranged to homogenize the EUV light received by the first aperture. The first shape is different from the second shape or the first size is different from the second size.

Abstract: An anti-glare film and a method of fabricating the same. The anti-glare film includes a transparent substrate, a photocurable resin layer stacked on one surface of the transparent substrate, and a plurality of amorphous patterns formed on a surface of the photocurable resin layer. The anti-glare film can provide excellent diffusion of light, exhibit excellent brightness without deterioration of transmittance, and provide excellent front brightness and visibility when applied to polarizing plates and display devices.

Abstract: An optical component arranged for use in a low pressure environment including: a surface arranged to receive extreme ultra-violet (EUV) light and a coating, on the surface, arranged to block at least one contaminant in the low pressure environment from binding to the surface. A method of mitigating contamination of a surface of an optical component, including: inserting the optical component into a chamber for a semi-conductor inspection system, controlling a temperature and a pressure within the chamber, introducing a blocking material, in a gaseous state, into the chamber, coating a surface of the optical component with the blocking material, and preventing, using the coating, a contaminant in the chamber from binding to the optical component.

Abstract: Lighting devices and methods for providing daylight to the interior of a structure are disclosed. Some embodiments disclosed herein provide a daylighting device including a tube having a sidewall with a reflective interior surface, a light collecting assembly, and a light reflector positioned to reflect daylight into the light collector. In some embodiments, the light collector is associated with one or more light-turning and/or light reflecting structures configured to increase the amount of light captured by the daylighting device. Optical elements may allow for the absorption and/or selective transmission of infrared light away from an interior of the daylighting device.

Abstract: A multi-band aperture filter for optically coupling to a focal plane array (FPA) of a camera includes a substrate, and a first spectral coating on a first surface of the substrate that passes both a first longer and a second shorter wavelength band. A second spectral coating that passes the longer wavelength band and blocks the shorter wavelength band is on an outer annulus region, but not on an inner region on the first surface or a second surface of the substrate. The second spectral coating provides a larger aperture area for the longer wavelength band as compared to an aperture area for the shorter wavelength band to passively realize different F-numbers for the bands to provide substantially matched beam spot sizes on the detector array for the longer wavelength band and the shorter wavelength band, such as a long-wave infrared (LWIR) band and a mid-wave IR (MWIR) band.

Abstract: To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals.

Abstract: Solar-redshift systems comprise an integral array of redshift modules, each having at least a focusing device, a target, and a quantum-dot vessel. The quantum-dot vessel contains quantum dots that emit light having an emission wavelength. The focusing device directs incident solar radiation through a focusing gap and toward the quantum-dot vessel, or into a slab waveguide and then toward the quantum-dot vessel, causing the quantum dots to emit redshifted light having the emission wavelength. The redshifted light is directed to the target, examples of which include a photovoltaic material or a living photosynthetic organism. The target has increased sensitivity or response to photons having the wavelength of the redshifted light. A trapping reflector component of the quantum-dot vessel prevents loss of redshifted light to the environment outside the solar-redshift system and allows undesirable infrared light to be removed from the system.

Abstract: A transparent luminescent solar concentrator is provided. In another aspect, a luminescent solar concentrator absorbs outside of visible light and emits outside of visible light. A further aspect of a luminescent solar concentrator employs nanocrystal clusters embedded in a polymeric matrix. In still another aspect, a unique ligand and luminophore host pairing is used for a solar concentrator.

Abstract: A camera objective for a camera includes a mask having a plurality of masking sections which are permeable for radiation of a first spectral range and are impermeable for radiation of a second spectral range different from the first spectral range. A camera system includes a digital camera for taking images. The camera system includes such a camera objective and an optoelectronic sensor arrangement having a plurality of sensor elements for generating exposure-dependent received signals which form a respective image. The plurality of sensor elements includes a first group of sensor elements for generating received signals in dependence only on radiation of the first spectral range and a second group of sensor elements for generating received signals in dependence on radiation of the second spectral range.

Abstract: The present application is directed to an optical filter system for use in a solar simulator, and includes at least one supplemental filter configured not to transmit light having a wavelength of 295 nm or less and to output at least one conditioned signal at least one WG320 optical filter configured to be irradiated by the conditioned signal and output at least one partially filtered signal having a wavelength of about 300 nm or greater, and at least one UG11 pass filter configured to be irradiated by the partially filtered signal and output at least one output signal having a wavelength of about 300 nm to about 400 nm.

Abstract: An optical device for microscopic observation 4 comprises: a cold stop 13 having openings 13d, 13e corresponding to a low-magnification microscope optical system 5 and being a stop member arranged in a vacuum vessel 12 to let the light from the sample S pass to the camera 3; a warm stop 10 having an opening 14 corresponding to a high-magnification microscope optical system 5 and being a stop member arranged outside the vacuum vessel 12 to let the light from the sample S pass toward the cold stop 13; and a support member 11 supporting the warm stop 10 so that the warm stop can be inserted to or removed from on the optical axis of the light from the sample S, wherein the warm stop 10 has a reflective surface 15 on the camera 3 side and wherein the opening 14 is smaller than the openings 13d, 13e.

Abstract: Anti-reflection glass, of a smooth tact, with an aspect that does not reflect light and is pleasant at sight and glass products made therefrom are included in the present invention. Such products may in some aspects have characteristics defined by values of transmittance, absorbance, reflectance, roughness and a series of micrographs realized with a microscope of atomic force to see the morphology and structure of the anti-reflection glass.

Abstract: An extreme ultraviolet light source apparatus using a spectrum purity filter capable of obtaining EUV light with high spectrum purity. The apparatus includes a chamber; a target supply unit for supplying a target material; a driver laser using a laser gas containing a carbon dioxide gas as a laser medium, for applying a laser beam to the target material to generate plasma; a collector mirror for collecting and outputting the extreme ultraviolet light radiated from the plasma; and a spectrum purity filter provided in an optical path of the extreme ultraviolet light, for transmitting the extreme ultraviolet light and reflecting the laser beam, the spectrum purity filter including a mesh having electrical conductivity and formed with an arrangement of apertures having a pitch not larger than a half of a shortest wavelength of the laser beam applied by the driver laser.

Abstract: A laser source assembly for providing an assembly output beam includes a first MIR laser source, a second MIR laser source, and a beam combiner. The first MIR laser source emits a first MIR beam that is in the MIR range and the second MIR laser source emits a second MIR beam that is in the MIR range. Further, the beam combiner spatially combines the first MIR beam and the second MIR beam to provide the assembly output beam. With this design, a plurality MIR laser sources can be packaged in a portable, common module, each of the MIR laser sources generates a narrow linewidth, accurately settable MIR beam, and the MIR beams are combined to create a multiple watt assembly output beam having the desired power.

Abstract: An apparatus for controlling propagation of an electromagnetic wave includes a metamaterial having an array of cells, each cell containing a metallic structure having a resonant frequency; a plurality of devices integrated in the metamaterial, each of said devices being in electrical communication with a metallic structure in a cell in the array of cells; and a controller for electrically activating each of said plurality of devices to cause said resonant frequency to change, thereby causing at least one of a permeability and permittivity of the metamaterial to change.

Abstract: The invention relates to a method for analyzing a defect of a photolithographic mask for an extreme ultraviolet (EUV) wavelength range (EUV mask) comprising the steps of: (a) generating at least one focus stack relating to the defect using an EUV mask inspection tool, (b) determining a surface configuration of the EUV mask at a position of the defect, (c) providing model structures having the determined surface configuration which have different phase errors and generating the respective focus stacks, and (d) determining a three dimensional error structure of the EUV mask defect by comparing the at least one generated focus stack of the defect and the generated focus stacks of the model structures.

Abstract: The invention relates to an optical element for a projection exposure apparatus for semiconductor lithography comprising an optically active surface and at least one cooling component for cooling the optical element, wherein the cooling component is connected to at least two separate cooling circuits and embodied in such a way that the optically active surface can be cooled to a greater extent in at least one partial region than in a further partial region. The invention furthermore relates to a projection exposure apparatus comprising an optical element according to the invention.

Abstract: Provided are an electromagnetic wave absorber having a multi-layered structure absorbing an electromagnetic wave, particularly, a terahertz wave, and a method of fabricating the electromagnetic wave absorber. The electromagnetic wave absorber includes a substrate having a predetermined refractive index for an electromagnetic wave, and a plurality of glass spheres arrayed into at least one layer on an upper part of the substrate.

Abstract: A head-mounted display (HMD) may include an eye-tracking system, an HMD-tracking system and a display configured to display virtual images. The virtual images may present an augmented reality to a wearer of the HMD and the virtual images may adjust dynamically based on HMD-tracking data. However, position and orientation sensor errors may introduce drift into the displayed virtual images. By incorporating eye-tracking data, the drift of virtual images may be reduced. In one embodiment, the eye-tracking data could be used to determine a gaze axis and a target object in the displayed virtual images. The HMD may then move the target object towards a central axis. The HMD may also record data based on the gaze axis, central axis and target object to determine a user interface preference. The user interface preference could be used to adjust similar interactions with the HMD.

Abstract: An optical filter including a near infrared absorbing layer on a glass substrate, in which adhesiveness between the glass substrate and the near infrared absorbing layer is firm, high reliability is enabled in uses under a high temperature and high humidity environment, and manufacturing yield is secured, and a high reliability solid-state imaging device having the optical filter are provided. An optical filter includes: a glass substrate; and a near infrared absorbing layer formed on one principal surface of the glass substrate, wherein the near infrared absorbing layer is obtained by reacting a composition for forming the near infrared absorbing layer on the glass substrate and the composition contains a transparent resin having a fluorene skeleton and a reactivity group; a near infrared absorbing dye; and a silane coupling agent and/or oligomer thereof having a hydrolyzable group and a functional group which have reactivity for the reactivity group.

Abstract: A structure (100) comprises a transparent substrate (110) having a surface (104), and the surface (104) has a three dimensional pattern (310) resulting from a combination of at least two surface waves (312, 314, 316). The at least two surface waves (312, 314, 316) differ in wavelength by in maximum 50% based on the wavelength of the wave of the at least two surface waves (312, 314, 316) having the bigger wavelength. Each wavelength of the at least two waves (312, 314, 316) is selected from the range of 200 to 900 nm. The structure (100) may be integrated into plastic films or sheets or glazings, especially for the purpose of light management.

Abstract: A collector system for extreme ultraviolet (EUV) radiation includes a collector mirror and a radiation-collection enhancement device (RCED) arranged adjacent an aperture member of an illuminator. The collector mirror directs EUV radiation from an EUV radiation source towards the aperture member. The RCED redirects a portion of the EUV radiation that would not otherwise pass through the aperture of the aperture member or that would not have an optimum angular distribution, to pass through the aperture and to have an improved angular distribution better suited to input specifications of an illuminator. This provides the illuminator with greater amount of useable EUV radiation than would otherwise be available from the collector mirror alone, thereby enhancing the performing of an EUV lithography system that uses such a collector system with a RCED.

Abstract: The invention relates to an optical arrangement comprising an optical module having a first carrier body to which there are attached at least one optical element and a plurality of first mounting elements, and a housing having a second carrier body for at least one further optical element, wherein a plurality of second mounting elements is attached to the carrier body. Also comprised is a movement device for displacing the first carrier body relative to the second carrier body in a movement direction between a removal position from which the optical module can be removed from the housing and a mounting position in which the movement device presses the first mounting elements against the second mounting elements. The invention relates also to an optical module and to a method for correctly positioning an optical module in a housing.

Abstract: Apparatus and methods are provided for use with solar energy. An optical concentrator and splitter (OCS) includes a non-planar bottom surface having symmetrical halves, each half defined by an off-axis section of a parabola. The bottom surface bears a dielectric surface treatment. The OCS is configured to concentrate a first spectral portion of photonic energy through respective side surfaces, and to concentrate a second spectral portion through the bottom surface. Targets such as photovoltaic cells or others receive the concentrated first and second spectral portions, respectively.

Abstract: An internal IR filter assembly for an illuminator has a lamp disposed within a reflector with a face plate. A spring-biased IR filter is shaped as a hollow sleeve telescopically disposed over the lamp. A fixed cylindrical pedestal has one end coupled to the face plate. A sliding cylindrical mount is coupled to the IR filter and telescopically disposed over the fixed pedestal. A gear drive is engaged to a driven gear or hub. A motor is coupled to the gear drive to selectively and reversibly rotate the gear drive. The driven gear is coupled to the sliding cylindrical mount of the IR filter to selectively and reversibly translate the IR filter with respect to the lamp. At least one rod is coupled to the driven gear to prevent the rotation of the driven gear. The rod is slidable within the illuminator but rotationally fixed relative to the illuminator.

Abstract: An electronic device may be provided with electronic device structures such as housing structures and structures associated with electrical components. The electronic device structures may be attached to each other using ultraviolet and visible light curable adhesive. A layer of adhesive may be interposed between electronic device structures. A light source may generate ultraviolet light. The structures may include an ultraviolet-light-transparent structure through which the ultraviolet light passes to illuminate and cure the adhesive. The ultraviolet-light-transparent structure may form one of multiple shots of injection molded plastic in a device structure, may be formed using a plastic that is opaque at visible wavelengths, or may have a coating such as a metal coating to help reflect ultraviolet radiation onto the adhesive. Perforations in the coating may be used to pass ultraviolet radiation to the adhesive.

Abstract: A magnification device including a housing having a distal open end and a proximal open end is disclosed. The housing includes an optical system including one or more objective lenses adjacent the distal open end, and one or more eye lenses adjacent the proximal open end, the optical system produced a desired level of magnification; and a filtering system having first filter selectively filtering a first group of wavelengths and a second filter selective filtering a second group of wavelengths. The first and second filters having an optical density selected based on a magnification level of the optical system. A vision enhancing assembly including a carrier device and one or more magnification devices coupled to the carrier device is also disclosed, wherein the magnification devices include filters that have optical densities based on a magnification level.

Abstract: An aperture mechanism for night vision goggles (NVG) has a first end, a second end, a lens engaging portion, and a cone portion. A lens engaging portion has a recession allowing attachment of the aperture mechanism to a light admitting end of the NVG. A cone portion is opposite the lens engaging portion. Together the lens engaging portion and the cone portion form an aperture. The aperture mechanism increases the depth of field of the NVG for applications involving small object-to-goggle distances, such as in simulators or simulator environments. In a simulator system, the aperture mechanism can be attached to NVG such that at least a portion of light from a display screen is blocked. The light output of the display screen can be increased such that the depth of field remains higher but the image produced does not become darker.

Abstract: Transparent tags with encoded data include both a base mirror component and a matrix component, and may optionally include a filter component. These components are combined to achieve a system having a tag that absorbs infrared light in particular portions and reflects infrared light in other portions, presenting a pattern which encodes the data included in the tag to sensors of a display panel. This combination of components also reduces near infrared and/or red ambient light that can be sensed by the sensor in the display panel, reducing interference from such ambient light when identifying the pattern while enabling the tag to be substantially visibly transparent to a user.

Abstract: A lens includes a first optical surface, and a first cut end surface outside the first optical surface. The first optical surface has a SWS configured to reduce reflection of light. The first cut end surface has a SWS configured to reduce reflection of light and a reflection surface configured to reflect light having a predetermined wavelength.

Abstract: A near-infrared (NIR) optical shutter comprises a multiple-bandpass filter that is characterized by a bandstop filter region located between first and second bandpass filter regions. The first bandpass filter region passes visible light; the bandstop filter region blocks NIR light of wavelengths within a NIR light sensor band region; and the second bandpass filter region passes NIR light of longer wavelengths than a longer wavelength boundary of the NIR light sensor band region. A polarization state changer positioned between NIR polarizing filters and optically associated with the multiple-bandpass filter causes visible light transmission selectively in first and second light states. The polarization state changer in the first light state causes substantially reduced optical shutter transmission of NIR light in the second bandpass filter region and in the second light state causes substantially increased optical shutter transmission of NIR light in the second bandpass filter region.

Abstract: Conductive nanoshells are oriented so as to redirect incident radiation as a function of wavelength. Nanoshells can be formed on templates such as nanospheres or gratings and embedded in an elastomeric layer. In some examples, conductive nanoshells are coupled to a layer that is configured to unbuckle and buckle as a function of temperature, so that radiation in one or more wavelength ranges is directed differently at different temperatures. Building windows can include such layers to that infrared radiation is reflected on warm days and directed into a building on cool days. Such layers can also direct incident visible radiation to a room ceiling so as to enhance interior lighting.

Abstract: A low emissivity and EMI shielding transparent composite film typically for use in association with window glazing and comprising a transparent film substrate having on one side thereof an underlayer of abrasion resistant hardcoat material with at least one infrared reflective layer covering the underlayer, typically a metallic layer which may be encased in metal oxide layers, which is then covered with a thin external protective top coat of a cured fluorinated resin.

Abstract: A heat reflector for temporarily covering of a window or a door to reflect sunlight and reduce heat transfer therethrough includes a metallized, biaxially-oriented polyethylene terephthalate sheet. The heat reflector can be sold in kit form comprising the sheet of metallized polyethylene foil; a cutting element for cutting the sheet of metallized polyethylene foil to fit the window or door; a mounting element for temporarily mounting the polyethylene foil layer onto a window or door; and a squeegee for smoothing out the metallized polyethylene foil on the window or door.

Abstract: Embodiments disclosed herein relate to a filter (100). In one embodiment, the filter includes a pattern (120). The pattern may reflect or fluoresce non-visible light.

Abstract: A fluorescence measurement system comprising a broadband light source and acousto-optical turnable filter (AOTF) controlled by a control unit using an acoustic RF signal provided by a Voltage Controlled Oscillator (VCO).

Abstract: A projection optical apparatus projects an image generated by an image generator onto a projection face by passing the image through a plurality of optical elements and an exit window. The projection optical apparatus includes an invisible-light reduction device to cut invisible light. The invisible-light reduction device prevents intrusion of the invisible light into the projection optical apparatus.

Abstract: Light-reflective structures comprising a binding material configured as an inverse opal having reflections of at least two wavelengths and methods of producing the light-reflective structures are described herein. The wavelengths reflected by the light-reflective structures may be tuned by external stimuli. In an example, silk-fibroin inverse opals have two reflection wavelengths that may be shifted based on changes in humidity.