A plane illumination apparatus has an optical device, an irradiation unit, and a light guide plate. The irradiation unit makes the coherent light beams scan the surface of the optical device, the light guide plate comprises a light take-out portion to take out coherent light beams to outside while making coherent light beams propagate between a first end face on which coherent light beams from the optical device are incident and a second end face provided to face the first end face, the specific zone is provided inside the light take-out portion or along the first end face, or along the second end face, the light take-out surface is a third end face that is connected to the first and second end faces, and the irradiation unit is provided at a rear side of a fourth end face that is an opposite side to the light take-out surface.

A three-dimensional holographic display device includes a light emitting diode (LED) array including a plurality of light sources controlled to sequentially output light according to a preset pattern, a lens configured to refract light incident from the LED array, a spatial light modulator (SLM) configured to modulate light incident from the lens, and a processor configured to generate a plurality of holographic signals each comprising depth information adjusted according to an arrangement location of each of the plurality of light sources, and for each of the plurality of light sources, control the SLM to modulate the light based on a holographic signal corresponding to the light source.

Provided are holographic displays and operating methods of the holographic display. The holographic display includes a backlight portion configured to emit light for displaying an image; a deflector configured to control a direction at which the image is displayed; a lens portion configured to control a location where the image to be displayed is formed to match a location that satisfies a diffraction condition; and a panel portion configured to display a 3D image by combining the image to be displayed with an interference pattern generated with respect to an overlapped hologram.

A liquid crystal grating and its fabrication method, and a display panel are provided in the present disclosure. The liquid crystal grating includes a first light adjustment component and a second light adjustment component, disposed oppositely. The first light adjustment component includes a first liquid crystal panel and a first polarization adjustment component; the second light adjustment component includes a second liquid crystal panel and a second polarization adjustment component; and using a second direction as an extending direction of a rotation axis, when the first light adjustment component is rotated 180° around the rotation axis, an alignment direction of the first liquid crystal panel is in parallel with an alignment direction of the second liquid crystal panel, and an optical axis direction of the first polarization adjustment component is in parallel with an optical axis direction of the second polarization adjustment component.

Provided is a holographic display apparatus including: a spatial light modulator that modulates a wavefront of a reference beam to form a hologram image; an optical element arranged to change a position of a viewing window of the hologram image off-axis by a first angle; and an image processor that generates hologram data according to the position of the viewing window of the hologram image and a hologram image to be reproduced, and provides the hologram data to the spatial light modulator. The hologram image formed by the spatial light modulator is viewable from a side of the spatial light modulator.

A beam deflection apparatus includes a first beam deflector that deflects light in a first direction and a second beam deflector that deflects light in a second direction perpendicular to the first direction, wherein the first beam deflector and the second beam deflector each include a first region for deflecting light of a first wavelength and a second region for deflecting light of a second wavelength, and a ratio of a spatial period of a signal applied to first drive electrodes arranged in the first region of the first beam deflector to the first wavelength is the same as a ratio of a spatial period of a signal applied to second drive electrodes arranged in the second region of the first beam deflector to the second wavelength.

An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.

Provided are holographic displays and operating methods of the holographic display. The holographic display includes a backlight portion configured to emit light for displaying an image; a deflector configured to control a direction at which the image is displayed; a lens portion configured to control a location where the image to be displayed is formed to match a location that satisfies a diffraction condition; and a panel portion configured to display a 3D image by combining the image to be displayed with an interference pattern generated with respect to an overlapped hologram.

Provided are holographic displays and operating methods of the holographic display. The holographic display includes a backlight portion configured to emit light for displaying an image; a deflector configured to control a direction at which the image is displayed; a lens portion configured to control a location where the image to be displayed is formed to match a location that satisfies a diffraction condition; and a panel portion configured to display a 3D image by combining the image to be displayed with an interference pattern generated with respect to an overlapped hologram.

In a method for forming a holographic image, light is provided to a flat-panel holographic video display that includes waveguide elements that each have a light-guiding substrate and an array of transducers configured to produce a diffraction grating comprising surface acoustic waves. The grating causes the waveguide to outcouple light, focusing it to, or producing wavefront curvatures consistent with it having emanated from, one or more points, in order to form a holographic image. The transducer array may include a large number of densely packed, vertically-adjacent transducers for each hogel for full parallax or may include a small number of vertically-adjacent transducers and a cylindrical optical element for each hogel. The display may be edge-illuminated by a collinear multicolor source. The substrate exit face may have nanopatterned areas alternated with flat areas in order to create regions of optimal internal reflection next to regions of low reflection.