The invention relates to a diffractive waveguide display element comprising a waveguide body (13) having a first surface and a second surface opposite to the first surface, an outcoupling-diffractive optical element on said first surface for coupling light propagating inside the waveguide body out of the waveguide body, and a narrow-band reflector element (21) on said second surface. The invention also relates to a display device comprising such element.

A bandpass filter may include a set of layers. The set of layers may include a first subset of layers. The first subset of layers may include hydrogenated germanium (Ge:H) with a first refractive index. The set of layers may include a second subset of layers. The second subset of layers may include a material with a second refractive index. The second refractive index may be less than the first refractive index.

Disclosed herein is a multi biometric terminal that includes a host system capable of recognizing two or more physical features. The host system includes a biometric data input unit configured to acquire biometric data of a user, and a biometric data identification unit configured to compare the acquired biometric data with pre-registered biometric data of the user to perform identification. When a body of the user approaches in a non-contact manner, the biometric data input unit receives a plurality of types of biometric data from the body. The host system is accommodated in a single module or housing.

The vehicle mirror includes a high-Re retardation film and a reflective layer. The high-Re retardation film has a front retardation of 5,000 nm or more, and the reflective layer is a reflective layer that is reflective in an unpolarized manner, such as a reflective metal layer. The vehicle mirror may be a vehicle mirror further including an image display device, wherein the high-Re retardation film, the reflective layer, and the image display device are disposed in this order, and the reflective layer is transflective.

A composition is provided, including water, a base, and surface-modified inorganic oxide nanoparticles dispersed in the water. The nanoparticles are functionalized with an alpha-hydroxy acid or its salt. An article is also provided, including a substrate in and layers containing bi-layers. A portion of the layers include surface-modified inorganic oxide nanoparticles functionalized with an alpha-hydroxy acid or its salt. A dielectric mirror is also provided, including a substrate, a first stack of bi-layers disposed on the substrate, and a second stack of bi-layers positioned in planar contact with the first stack. The second stack of bi-layers exhibits a refractive index of less than 1.50. Further, an exposed lens retroreflective article is provided including a binder layer, a layer of transparent microspheres partially embedded in the binder layer, and a reflective layer between the binder layer and the microspheres including a dielectric mirror. Additionally, methods of making compositions and articles are provided.

There is provided a filter for filtering electromagnetic radiation, wherein said filter is arranged to transmit electromagnetic radiation of a first predetermined wavelength and to block transmission of electromagnetic radiation of a second, different predetermined wavelength; said filter comprising a first metamaterial. Optionally, the metamaterial may be formed of a plurality of material elements wherein each material element is at least one-dimensional and the size of the material element along each dimension is no greater than the size of the second predetermined wavelength. The filter comprises a second metamaterial arranged to provide second filtering of electromagnetic radiation.

A high-chroma omnidirectional structural color multilayer structure is provided. The structure includes a multilayer stack that has a core layer, a dielectric layer extending across the core layer, and an absorber layer extending across the dielectric layer. An interface is present between the dielectric layer and the absorber layer and a near-zero electric field for a first incident electromagnetic wavelength is present at this interface. In addition, a large electric field at a second incident electromagnetic wavelength is present at the interface. As such, the interface allows for high transmission of the first incident electromagnetic wavelength and high absorption of the second incident electromagnetic wavelength such that a narrow band of reflected light is produced by the multilayer stack.

Provided in a phase shifting device including a plurality of metal layers and a plurality of first dielectric layers, a metal layer of the plurality of metal layers and a first dielectric layer of the plurality of first dielectric layers being alternately stacked in a first direction, and a second dielectric layer disposed on a side surface of the stacked structure in a second direction, wherein the first dielectric layer includes a first material having a first dielectric constant and the second dielectric layer includes a second material having a second dielectric constant, and wherein the second dielectric constant is greater than the first dielectric constant.

An apparatus includes an optical device that includes a substrate, a first layer of material over the substrate, and a second layer of material comprising an optical coating over the first layer of material. The first layer of material creates a first stress within the optical device that counteracts a second stress within the optical device created by the second layer of material. The optical device may also include a third layer of material positioned between the substrate and the first layer of material. In some cases, the second layer of material creates a compressive stress within the optical device, and the first layer of material creates a tensile stress within the optical device that counteracts the compressive stress within the optical device.

A high-chroma omnidirectional structural color multilayer structure is provided. The structure includes a multilayer stack that has a core layer, a dielectric layer extending across the core layer, and an absorber layer extending across the dielectric layer. An interface is present between the dielectric layer and the absorber layer and a near-zero electric field for a first incident electromagnetic wavelength is present at this interface. In addition, a large electric field at a second incident electromagnetic wavelength is present at the interface. As such, the interface allows for high transmission of the first incident electromagnetic wavelength and high absorption of the second incident electromagnetic wavelength such that a narrow band of reflected light is produced by the multilayer stack.