An optical device includes an array of light-emitting elements, including a first subset of light-emitting elements and a second subset of light-emitting elements. The first subset of light-emitting elements is configured to emit light having wavelength L.sub.1. The device includes a high refractive index material selectively disposed on the second subset of light-emitting elements and an array of optical elements positioned so as to be illuminated by the first subset of light-emitting elements and by the second subset of light-emitting elements. The optical elements are regularly arranged in a common plane at a pitch P, the common plane is located a distance D from the array of light-emitting elements, and P.sup.2≈2L.sub.1D/N, N being an integer greater than or equal to 1.

A light projecting apparatus is disclosed. The apparatus has a head with first and second light sources. There is a first reflector and a second reflector respectively disposed proximate to the first and second light sources. Each of the first and second reflectors has a concave reflective surface and a convex reflective surface configured to form light emitted by the respective light source into an illumination pattern having a central region having a substantially uniform distribution of luminous intensity and a taper region having a tapered luminous intensity.

A vortex beam-excited precision grating displacement measurement apparatus, which performs displacement measurement by taking a vortex beam carrying topological charges as an excitation light source of a grating and by using the interference of a ±m-order diffracted vortex beam. In the vortex beam-excited precision grating displacement measurement method and apparatus, the displacement p/m of the measured displacement corresponds to the rotation of a circle 2π rad of an interference petal pattern, and then the rotation of 1° of the interference petal pattern corresponds to the measured displacement amount of p/360m. Compared with a conventional grating measurement method, the present disclosure provides a grating interference sensing signal that realizes a higher optical subdivision rate itself.

Device (1) for processing light radiation, comprising: —an optical input (2) for receiving an input beam from an optical source (3) and for propagating in the device (1) an input radiation, an optical output (4) for emitting an output beam having predetermined spatial parameters, an MPLC conversion device (5) which is arranged between the optical input (2) and the optical output (4) and which is configured to spatially separate, in a separation plane (7), the input radiation into useful radiation, in a target mode, which is propagated to the optical output (4) and into an interference radiation. The processing device also comprises at least one device (8) for blocking the interference radiation, which blocking device is arranged in the separation plane (7) so that it does not contribute to the output beam.

A beam expanding film includes a first material layer and a photonic crystal layer that expands a width of incident light and emits light having an expanded width. The photonic crystal layer includes a first material layer and a plurality of second material layers buried in the first material layer. A holographic display apparatus includes a backlight unit configured to provide coherent collimated light; a beam expanding film described above and facing the backlight unit; a flat panel arranged between the backlight unit and the beam expanding film to provide a hologram; and a lens configured to focus a holographic image on a space.

A light projecting apparatus is disclosed. The apparatus has a head with first and second light sources. There is a first reflector and a second reflector respectively disposed proximate to the first and second light sources. Each of the first and second reflectors has a concave reflective surface and a convex reflective surface configured to form light emitted by the respective light source into an illumination pattern having a central region having a substantially uniform distribution of luminous intensity and a taper region having a tapered luminous intensity.

A beam irradiation device that irradiates a plurality of electron beams includes a multibeam optical system that emits the plurality of beams to be irradiated on a target; and a controller that controls an irradiation state of each of the plurality of beams in accordance with change in a relative position between the target and the multibeam optical system, and based on the irradiation state of a first beam of the plurality of beams, controls the irradiation state of a second beam of the plurality of beams.

A diffuser lens includes a first annular lens segment and a second annular lens segment. The first and the second lens segments are concentric. A refractive index of the first and second lens segments in a cross-section along a plane including an optical axis of the diffusor lens is described by a refractive index profile which varies in a direction perpendicular to the optical axis. The refractive index profile includes a first sub-profile, which describes the refractive index profile of the first lens segment, and a second sub-profile, which describes the refractive index profile of the second lens segment. The first sub-profile transitions to the second sub-profile at an interface. These first and second sub-profiles have slopes with opposite signs.

A laser projector includes a laser assembly, a beam combination mirror group and a phase delaying component. The laser assembly includes a red laser light emitting region, a blue laser light emitting region and a green laser light emitting region. Red laser light is polarized in a first direction, green laser light is polarized in a second direction, and blue laser light is polarized in a third direction. The beam combination mirror group combines the red laser light, the blue laser light and the green laser light. The phase delaying component is on a light emitting path of at least one of the red laser light, the blue laser light the green laser light, and changes a polarization direction of the at least one of the red laser light, the blue laser light or the green laser light before being output by the beam combination mirror group.

A light-emitting device assembly includes a concave optical collector, a light-emitting device, and a light-escape surface. The collector redirects incident light by reflection, scattering, or reradiation. The light-emitting device emits device output light to propagate within the optical collector. The light-escape surface extends across an open end of the collector and exhibits (i) incidence-angle-dependent transmission of light that decreases with increasing incidence angle, or (ii) transmissive redirection of light to propagate at an angle less than a corresponding refracted angle, that are imparted by an array of nano-antennae, a partial photonic bandgap structure, a photonic crystal, an array of meta-atoms or meta-molecules, or a multi-layer dielectric thin film. Assembly output light transmitted by the light-escape surface includes first and second portions of the device output light that propagate within the collector without and with redirection, respectively, within the collector by the light-escape surface.