A method of manufacturing a full-color holographic optical element in a full-color holographic optical element manufacturing apparatus including a lens and a holographic recording medium located farther away than a focal length of the lens, the method including: allowing a signal beam including a mixture of laser beams having wavelengths of R (Red), G (Green), and B (Blue) to be incident on the lens; and recording a hologram in such a manner that a reference beam including a mixture of laser beams having wavelengths of R, G, and B is allowed to be incident on the holographic recording medium, wherein the holographic recording medium is configured with a single medium.

A method displays a binocular hologram image. The method includes generating a light beam of an incident wave field having coherence, expanding the generated light beam to the size of the active area of a display, converging the expanded light beam on the respective positions of the eyes of a user, generating digital hologram content, and displaying a hologram image based on the converged light beam and on the digital hologram content.

Light from an array of laser light sources are spread to cover the modulating face of a DMD or other modulator. The spread may be performed, for example, by a varying curvature array of lenslets, each laser light directed at one of the lenslets. Light from neighboring and/or nearby light sources overlap at a modulator. The lasers are energized at different energy/brightness levels causing the light illuminating the modulator to itself be modulated (locally dimmed). The modulator then further modulates the locally dimmed lights to produce a desired image. A projector according to the invention may utilize, for example, a single modulator sequentially illuminated or separate primary color modulators simultaneously illuminated.

A method and apparatus for generating coherent light, and a display apparatus using coherent light are provided. A wide-angle coherent light generation apparatus may focus parallel light onto a focal point, and may generate coherent light at a wide angle, using an optical device.

There is disclosed herein a display device comprising a picture generating unit, a waveguide pupil expander and a viewer-tracking system. The picture generating unit comprises a first display channel, a second display channel and a controller. The first display channel is arranged to output first spatially-modulated light of a first colour. The first spatially-modulated light corresponds to a first picture. The second display channel is arranged to output second spatially-modulated light of a second colour. The second spatially-modulated light corresponding to a second picture. The controller is arranged to drive the first display channel and second display channel. The waveguide pupil expander comprises a pair of parallel reflective surfaces. The waveguide pupil expander defines an input port and a viewing window. The input port is arranged to receive the first spatially-modulated light and the second spatially-modulated light. The viewing window is an area or volume within which a viewer may view the first picture and the second picture. The pair of parallel reflective surfaces is arranged to guide the first spatially-modulated light and the second spatially-modulated light from the input port to the viewing window by a series of internal reflections. The reflectivity of a first reflective surface of the pair of parallel reflective surfaces is provided by a graded coating. The graded coating is partially transmissive to light of the first colour and light of the second colour. The transmissivity of the graded coating is non-achromatic. The viewer-tracking system is arranged to determine a viewing position within the viewing window. The controller is arranged to maintain as substantially constant the colour balance of the first and second picture as seen from the viewing position based on the viewing position determined by the viewer-tracking system.

The present disclosure relates to a holographic display device and an electronic device. The holographic display device may include a light source, a light transmission structure, a first photonic crystal group, and a spatial light modulator. The light transmission structure has a light incident surface and a light exiting surface. The first photonic crystal group is disposed between the light incident surface and the light source. The first photonic crystal group includes various photonic crystals for dividing light emitted by the light source into light beams of different colors. The light beams of different colors are transmitted into the light transmission structure through the light incident surface and emitted through the light exiting surface. The spatial light modulator corresponds to the light exiting surface for modulating light beams of different colors emitted from the light exiting surface to form a holographic image.

A display article (10) includes a plurality of display areas (12, and 13a to 13c). Display areas adjacent to each other differ in at least one of an average hue, an average brightness and an average chroma and a first object to be displayed (21) is formed by a combination of the plurality of display areas (12, and 13a to 13c). At least one of the display areas (12, 13a to 13c) includes a Fourier transform hologram (20R, 20Y) configured to convert incident ray from a point light source or a laser light source into a second object to be displayed.

A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium, a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam, and a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.

A light-emitting device including at least a metal layer able to be heated and to propagate surface waves consecutive to the heating of the metal layer, with the metal layer being structured such that it comprises several diffraction patterns able to carry out a diffraction of the surface waves to free-space propagation modes, wherein a synthetic hologram is encoded such that a phase image of a pixel of the hologram is encoded by an offset in the position of one of the diffraction patterns, and a heater of the metal layer.

An optical reflective device for homogenizing light including a waveguide having a first and second waveguide surface and a partially reflective element is disclosed. The partially reflective element may be located between the first waveguide surface and the second waveguide surface. The partially reflective element may have a reflective axis parallel to a waveguide surface normal. The partially reflective element may be configured to reflect light incident on the partially reflective element at a first reflectivity for a first set of incidence angles and reflect light incident on the partially reflective element at a second reflectivity for a second set of incident angles.