A field-enhancing device includes at least one metal layer or a metal grating consisting of metal stripes or a dielectric grating. Usually the device is constructed on some substrate. The adhesive layer is advantageous when the next layer is metallic but is not needed with dielectric layers. The next layers to be constructed form a mirror structure that can also be omitted for simple field-enhancing device constructs. The mirror structure can be either a metal mirror structure or a distributed Bragg reflector structure (DBR). The next layer is the thin metal layer. This layer can be covered with a 1-D metal grating consisting of metal stripes or with a dielectric grating having similar geometry. The structure can also be fabricated without metals when dielectric grating is used as the field-enhancing part. Finally, a protective layer can be added on top of the structure.

A reflective composite material with a carrier consisting of aluminum with, on one side (A) of the carrier, an interlayer made of aluminum oxide, and with, above the interlayer, an optically active reflection-boosting multilayer system. In order to provide a high-reflectivity composite material of this kind which exhibits improved electrical connectivity when surface-mounting procedures are used, it is proposed that the thickness of the interlayer is in the range 5 nm to 200 nm, and that a layer of a metal or a metal alloy has been applied superficially on side (B) of the carrier that is opposite to the optically active reflection-boosting multilayer system, where the electrical resistivity at 25° C. of the metal or metal alloy is at most 1.2×10.sup.−1 Ω mm.sup.2/m, where the thickness of the layer applied superficially is in the range 10 nm to 5.0 μm.

Imaging apparatus includes a housing, with imaging optics mounted in the housing and configured to form an optical image, at a focal plane within the housing, of an object outside the housing. An image sensor, including a matrix of detector elements, is positioned at the focal plane in alignment with the imaging optics and is configured to output an electronic image signal in response to optical radiation that is incident on the detector elements. At least one emitter is fixed within the housing and is configured to emit a test beam toward one or more reflective surfaces within the housing, which reflect the test beam toward the image sensor. A processor is configured to process the electronic image signal output by the image sensor in response to the reflected test beam so as to detect a change in the alignment of the image sensor with the imaging optics.

Reflective optical element with extended service life for VUV wavelengths includes a substrate (41) and a metal layer (49) thereon. At least one metal fluoride layer (43) on the metal layer faces away from the substrate and at least one oxide layer (45) on the metal fluoride layer faces away from the substrate. The thicknesses of the layers on the metal layer facing away from the substrate are selected so that the electrical field of a standing wave, formed when a relevant wavelength is reflected, has a minimum in the region of the oxide layer. In addition, the relevant wavelength is selected so that, from a minimum VUV wavelength range to the relevant wavelengths, the integral over the extinction coefficients of the material of the at least one oxide layer is between 15% and 47% of the corresponding integral from the minimum wavelengths to a maximum wavelength.

The disclosure is directed to a highly reflective multiband mirror that is reflective in the VIS-NIR-SWIR-MWIR-LWIR bands, the mirror being a complete thin film stack that consists of a plurality of layers on a selected substrate. In order from substrate to the final layer, the mirror consists of (a) substrate, (b) barrier layer, (c) first interface layer, (d) a reflective layer, (e) a second interface layer, (f) tuning layer(s) and (g) a protective layer. In some embodiments the tuning layer and the protective layer are combined into a single layer using a single coating material. The multiband mirror is more durable than existing mirrors on light weight metal substrates, for example 6061-Al, designed for similar applications. In each of the five layer types methods and materials are used to process each layer so as to achieve the desired layer characteristics, which aid to enhancing the durability performance of the stack.

The present invention refers to a mirror comprising a plurality of one-dimensional photonic crystals, the mirror having very high reflectance in a very broad range of wavelengths, a broad range of directions, even hemispheric, and all the polarizations of the incident photons. The invention also refers to a method for designing said mirror and a photovoltaic cell comprising such a mirror.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The present disclosure provides for articles that exhibit structural colors through the use of an optical element, where structural colors are visible colors produced, at least in part, through optical effects. The optical element can include the reflective layer(s), constituent layers, and an optional textured surface. The optical element has a minimum percent reflectance in a wavelength range within the wavelength range of about 380 to 740 nanometers. The optical element imparts a structural color that corresponds substantially to the range of wavelength range.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The present disclosure provides for articles that exhibit structural colors through the use of an optical element, where structural colors are visible colors produced, at least in part, through optical effects. The optical element (e.g., a single layer reflector, a single layer filter, a multilayer reflector or a multilayer filter) can include the reflective layer(s), constituent layers, and an optional textured surface. The optical element has a minimum percent reflectance in a wavelength range within the wavelength range of about 380 to 625 nanometers. The optical element imparts a structural color that corresponds substantially to the range of wavelength range.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The present disclosure provides for articles that exhibit structural colors through the use of an optical element, where structural colors are visible colors produced, at least in part, through optical effects. The optical element (e.g., a single layer reflector, a single layer filter, a multilayer reflector or a multilayer filter) can include the reflective layer(s), constituent layers, and an optional textured surface. The optical element has a minimum percent reflectance in a wavelength range within the wavelength range of about 380 to 625 nanometers. The optical element imparts a structural color that corresponds substantially to the range of wavelength range.

Component surfaces are coated with thermally stable layers. In particular infrared mirror surfaces or surfaces of combustion chambers are coated with at least one layer consisting of thermally stable AlCrO in such a manner that the absorption, reflection or transmission of infrared radiations (hereinafter also called thermal radiations) is influenced.