III-Nitride layers having spatially controlled regions or domains of porosities therein with tunable optical, electrical, and thermal properties are described herein. Also disclosed are methods for preparing and using such III-nitride layers.

The present invention provides a reflective polarized-light separating diffraction-element usable in a wide wavelength region including an ultraviolet region, and an optical measurement device comprising the same. The reflective polarized-light separating diffraction-element comprises: a substrate (1); a reflection surface (2) formed on a surface of the substrate (1); and a lattice structured body assembly (3) that is provided on the reflection surface (2) and shows a form birefringence (Δn*). The lattice structured body assembly (3) consists of lattice structured bodies (3A, 3B, 3C and 3D) of four patterns having lattice structures of different azimuths. The lattice structured bodies (3A, 3B, 3C and 3D) of a plurality of patterns are aligned on the reflection surface 2 in a predetermined direction such that the azimuths of the lattice structures change in a structurally periodic manner.

A head-mounted device (HMD) contains a display, an optics block, a redirection structure, and an eye tracking system. The display is configured to emit image light and provide it to an eye of a user. The optics block is configured to direct the emitted light in order to allow it to reach the eye. The eye tracking system contains a camera, an illumination source, and a controller. The camera is configured to capture image data using infrared light reflected from the eye. The controller is configured to use this image data to determine eye tracking information. The illumination source is configured to illuminate the eye with infrared light for the purpose of taking eye tracking measurements. The redirection structure is configured to direct infrared light reflected from the eye to the eye tracking system. In multiple embodiments, redirection structures may comprise prism arrays, lenses, liquid crystal layers, or grating structures.

A system and method are provided for spectral shaping of light from a broadband source using a linear spatial light modulator (SLM). The system includes an illumination source generating light including a plurality of wavelengths, a lens to collimate the light and an aperture to define its angular spread, a diffraction grating to disperse the beam by wavelength, and a focusing element to focus the dispersed beams from the diffraction grating onto a plurality of pixels of the SLM. The SLM is configured to individually modulate the dispersed beams by diffracting light output therefrom into higher orders, where a diffraction angle of output light is greater than an input cone angle of incoming light from the illumination source.

A nanocomposite includes a plurality of nanoparticles, where each nanoparticle of the plurality of nanoparticles includes a TiO.sub.2 nanoparticle core characterized by a diameter between about 1 nm and about 20 nm and a surface .OH density below about 6.OH/nm.sup.2, and a nanoparticle shell conformally formed on surfaces of the TiO.sub.2 nanoparticle core. The nanoparticle shell is continuous and is thinner than about 2 nm. The nanoparticle shell includes a transparent material with a refractive index greater than about 1.7 for visible light. A valence band of the nanoparticle shell is more than about 0.1 eV lower than a valence band of the TiO.sub.2 nanoparticle core. A conduction band of the nanoparticle shell is more than about 0.5 eV higher than a conduction band of the TiO.sub.2 nanoparticle core.

A method for producing a volume hologram with at least one first area in a first color and at least one second area in a second color includes, providing a volume hologram layer made of a photopolymer; arranging a master with a surface structure on the volume hologram layer; exposing the master using coherent light, wherein light which is incident on at least one first partial area of the surface of the master is diffracted or reflected in the direction of the at least one first area of the volume hologram layer and light which is incident on at least one second partial area of the surface of the master is diffracted or reflected in the direction of the at least one second area of the volume hologram, and wherein the light diffracted or reflected by the first and second partial areas differs in at least one optical property.

The object of the present invention is to provide an optical information medium having a colored glossy effect which is single- or multi-colored in regions where a reflective layer is present, but colorless in regions where the reflective layer is absent. The optical information medium of the present invention includes a bonding part (receiving layer), at least one image part, and an adhesive layer (protective layer) covering the at least one image part, wherein each of the image part includes a micro-protrusion/depression structure including part having a micro-protrusion/depression structure on at least a part of the surface opposite to the bonding part, a reflective layer, and a mask layer, in the order from the bonding part (receiving layer), the micro-protrusion/depression structure including part is colorless or colored in one or more translucent or opaque color, and at least one of the micro-protrusion/depression structure including part of the image part is colored in one or more translucent or opaque color.

An optical arrangement for spectral decomposition of light is disclosed. In an embodiment the optical arrangement includes a reflection diffraction grating, a first medium with a refractive index n.sub.in arranged on a light incidence side of the reflection diffraction grating; and a second medium with a refractive index n.sub.G arranged on a side of the reflection diffraction grating that faces away from the light incidence side, with n.sub.in>n.sub.G, wherein the optical arrangement is configured in such a way that light impinges on the reflection diffraction grating from the first medium at an angle of incidence α, wherein a condition sin(α)>n.sub.G/n.sub.in is satisfied, wherein the reflection diffraction grating comprises a layer system with at least one unstructured layer and at least one structured layer, wherein the at least one structured layer has a periodic structure with a period p in lateral direction, and wherein the period p meets the following conditions: p<λ/[n.sub.in*sin(α)+n.sub.G] and p>λ/[n.sub.in*sin(α)+n.sub.in].

Provided is a feature for highly precisely manufacturing a concave diffraction grating that has a uniform diffraction grating pattern. This method for manufacturing a concave diffraction grating includes: preparing a flat diffraction grating that has a lattice groove and that also has an elongated section, a thin-film section, or a low-friction section formed outside of a region for forming a mold for the concave diffraction grating; mounting the flat diffraction grating on a convex substrate and acquiring the mold for the concave diffraction grating; and transferring the lattice groove in the mold to the concave substrate.

To improve brightness of image information visually recognized by a user while using plastic for a light guide plate. An image display element includes: a substrate made of resin; an incident diffraction grating that diffracts incident light; and an exit diffraction grating that emits the light, the incident diffraction grating being formed on a first surface of the substrate, the exit diffraction grating being formed on a second surface on a side opposite to the first surface of the substrate, and the exit diffraction grating being formed on one surface.