An optical waveguide is provided. The optical waveguide includes a base structure and a plurality of grating structures disposed at the base structure. The grating structures include a plurality of in-coupling grating structures configured to couple a plurality of lights into the optical waveguide. At least one of a grating period or a slant angle of a first in-coupling grating structure is different from at least one of a corresponding grating period or a corresponding slant angle of a second in-coupling grating structure. The grating structures also include a plurality of out-coupling grating structures configured to couple the lights out of the optical waveguide.

A device for producing a subwavelength hologram. The device comprises a metasurface layer attached to a substrate. The metasurface layer includes an array of plasmonic antennas that simultaneously encode both wavelength and phase information of light directed through the array to produce a hologram. The wavelength is determined by the size of the antennas, and the phase is determined by the orientation of the antennas.

In the present invention, by providing a 3D holographic display system comprising a modulation apparatus configured to modulate light emitted from a light source into a light wave corresponding to a 3D image, an optical apparatus configured to propagate the light wave into the first plane, and a diffraction apparatus configured to multiplex the propagated light wave to extend viewing angle of the 3D holographic display, a limited viewing zone of the holographic display determined by the SLM pixel pitch, may be extended by optical methods, such as using diffractive optical elements (DOE) for spatial-division multiplexing (SDM).

A display may have an array of pixels. Each pixel may have a light-emitting diode such as an organic light-emitting diode or may be formed from other pixel structures such as liquid crystal display pixel structures. The pixels may emit light such as red, green, and blue light. An angle-of-view adjustment layer may overlap the array of pixels. During operation, light from the pixels passes through the angle-of-view adjustment layer to a user. The viewing angle for the user is enhanced as the angular spread of the emitted light from the pixels is enhanced by the angle-of-view adjustment layer. The angle-of-view adjustment layer may be formed from holographic structures recorded by applying laser beams to a photosensitive layer or may be formed from a metasurface that is created by patterning nanostructures on the display using printing, photolithography, or other patterning techniques.

An active optical filter adapted for a spectacle lens, the active optical filter configured to filter light radiations over at least one predetermined range of wavelengths, wherein the full width at half maximum of the filtering function of the optical filter is smaller than or equal to 100 nm.

A method and system for forming a holographic structure in a material. The holographic structure is configured to project a selected target image in the far field under illumination of the holographic structure by a laser. The method calculates a modified design for the holographic structure that encodes a unique identifier within the holographic structure for projecting the target image. The method modifies the material by mapping features corresponding to the modified design into the material so as to form the holographic structure. A basic check of the authenticity of the material is performed by checking whether a projected replica of the target image is as expected. A more detailed check of the authenticity of the material is performed by directly inspecting the features in the holographic structure.

An apparatus for producing an optically variable film includes a laser configured to emit a beam, a telescoping lens section having a first lens and a second lens spaced apart by a first distance and an interferometer configured to direct the beam toward a workpiece. The laser may be operated at a predetermined power level and the first and second lenses are sized and spaced relative to one another to direct the beam onto the workpiece at about 200-230 dots per inch. The workpiece may include a polyethylene terephthalate (PET) layer configured to be ablated by the beam, forming a microstructure in the surface of the layer. The microstructure may be randomized and used to present non-chroma visual effects.

One example includes an injection-molded component comprising a surface surrounded by peripheral edges and which is formed via an injection-molding process. The surface includes a three-dimensional surface feature to render the surface as being non-planar across at least a portion of the surface. The surface also includes a plurality of holographic micro-features formed across the surface and being to interact with ambient light to provide a holographic image corresponding to an authentication mark associated with the injection-molded component.

A method of forming a security device includes selectively providing a high refractive index (HRI) layer to a first outwardly facing surface of a security device substrate, the HRI layer having a substantially transparent host material and particles having a dimension along at least one axis less than 200 nm, such that they are substantially non-scattering to visible light and the HRI layer is substantially transparent to visible light, and wherein; the particles have a refractive index of at least 1.8 and are present within the host material in a proportion such that the resultant refractive index of the HRI layer is at least 1.6. A corresponding security device, as well as security articles and security documents, are also disclosed.

A 2D hologram system with a matrix addressing scheme is provided. The system may include a 2D array of sub-wavelength hologram elements integrated with a refractive index tunable core material on a wafer substrate. The system may also include a matrix addressing scheme coupled to the 2D array of sub-wavelength hologram elements and configured to independently control each of the sub-wavelength hologram elements by applying a voltage.