Eyewear including an optical element, a controller, a support structure configured to support the optical element and the controller, light sources coupled to the controller and supported by the support structure, and a diffuser positioned adjacent to the light sources and supported by the support structure, the diffuser including microstructures that diffuse light emitted by the light sources in a radial anisotropic diffusion pattern or a prism-like diffusion pattern.

An illumination apparatus for reducing speckle effect in light reflected off an illumination target includes a laser; a linear diffuser positioned in an optical path between an illumination target and the laser to diffuse collimated laser light in a planar fan of diffused light that spreads in one dimension across at least a portion of the illumination target; and a beam deflector to direct the collimated laser light incident on the beam deflector to sweep across different locations on the linear diffuser within an exposure time for illumination of the illumination target by the diffused light. The different locations span a distance across the linear diffuser that provides sufficient uncorrelated speckle patterns, at an image sensor, in light reflected from an intersection of the planar fan of light with the illumination target to add incoherently when imaged by the image sensor within the exposure time.

An optically diffusive film includes an optical substrate layer with opposing first and second major surfaces; and an optical layer disposed on the second major surface of the optical substrate layer and including a structured major surface having a plurality of spaced apart elongated structures elongated along a same first direction and arranged at a substantially uniform density, each elongated structure including a peak such that, in a plane of a cross-section of the elongated structure that is parallel to the first direction and comprises the peak, the elongated structure has a substantially flat top region; wherein for substantially normally incident light and a visible wavelength range and an infrared wavelength range, the optical substrate layer has an average total transmittance or reflectance of greater than about 60% in the visible wavelength range and an average specular transmittance of greater than about 60% in the infrared wavelength range.

A liquid crystal display apparatus, includes: a light-condensing backlight unit; a liquid crystal panel including a first linear polarizer and a second linear polarizer; a light scattering film facing the second linear polarizer; and a third linear polarizer facing the light scattering film. The light scattering film includes a functional layer including an organic polymer compound and light scattering particles. The functional layer includes a particle layer in which a fraction of 60% by volume to 100% by volume of the light scattering particles included in the functional layer expands along a surface of the particle layer at which the light output from the liquid crystal panel is received, and the particle layer is concentrated to a region having a thickness of 1 to 80% of a total thickness of the functional layer, in a direction perpendicular to the contact surface.

A homogenizing module and a projection apparatus are provided. The homogenizing module is configured to homogenize a beam and includes an anisotropic diffuser and a homogenizer. The anisotropic diffuser is located on a transmission path of the beam. The beam has a first divergence angle in a first direction and a second divergence angle in a second direction after passing through the anisotropic diffuser. The first divergence angle is greater than the second divergence angle. The homogenizer is located on a transmission path of the beam from the anisotropic diffuser, and the homogenizer includes multiple optical elements. The size of any of the multiple optical elements in the first direction is greater than the size thereof in the second direction. The first direction is perpendicular to the second direction.

An artifact caused by secondary reflection is reduced. An imaging device according to an embodiment includes: a diffuser (110) that converts incident light into scattered light whose diameter is expanded in accordance with a propagation distance and outputs the scattered light; and a light receiver (132) that converts light diffused by the diffuser into an electric signal.

Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm.sup.2, allowing it to fit on mobile devices.

A light-diffuser includes a transparent resin and transparent particles dispersed in the transparent resin. The transparent resin has a refractive index different from that of the transparent particles, and at least one portion of an outer perimeter of each of the transparent particles, respectively, is made compatible with the transparent resin disposed in the vicinity of the transparent particles, respectively.

Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm.sup.2, allowing it to fit on mobile devices.

Provided is an image display device including an optical scanner configured to scan light emitted from a light source, a parallel light generator configured to generate the scanned light as parallel light, a prism configured to refract the parallel light, and a light direction changer including a plurality of points whereon the parallel light refracted by the prism is incident and configured to reflect or diffract the parallel light and change a traveling direction of the parallel light, wherein the prism is provided on a path of each light traveling from the optical scanner to the light direction changer to adjust an optical path difference of parallel light incident on each of the plurality of points of the light direction changer.