An all-optical hologram reconstruction system and method is disclosed that can instantly retrieve the image of an unknown object from its in-line hologram and eliminate twin-image artifacts without using a digital processor or a computer. Multiple transmissive diffractive layers are trained using deep learning so that the diffracted light from an arbitrary input hologram is processed all-optically to reconstruct the image of an unknown object at the speed of light propagation and without the need for any external power. This passive diffractive optical network, which successfully generalizes to reconstruct in-line holograms of unknown, new objects and exhibits improved diffraction efficiency as well as extended depth-of-field at the hologram recording distance. The system and method can find numerous applications in coherent imaging and holographic display-related applications owing to its major advantages in terms of image reconstruction speed and computer-free operation.

A holographic display and a method, performed by the holographic display, of forming a holographic image are disclosed. The holographic display includes an electrically addressable spatial light modulator (EASLM); a diffractive optical element (DOE) mask array arranged on the EASLM; and a controller configured to operate the holographic display to form a hologram image, wherein the controller is further configured to address the EASLM to backlight the DOE mask array required to form a set of hologram image voxels by turning on a corresponding EASLM pixel.

There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) minor enables rear illumination of a reflection hologram.

A floating image display device includes: an image forming device configured to form a source image; a waveguide configured to output a light of the source image to another location by guiding the light; a holographic optical device provided on a proceeding path of the light output from the waveguide, the holographic optical device including a hologram pattern that diffracts incident light of a certain incident angle region output from the waveguide by a set target diffraction angle and a floating element including a plurality of corner reflectors and forming a floating image of the source image by forming an image of the light output from the holographic optical device at a certain location in mid-air.

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.

An apparatus and method for displaying holograms. A compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

An electronic device may include an optical system that redirects light from a display module towards an eye box along an optical path. The optical path may include a holographic coupler and a resolution-enhancing holographic element. The holographic element may include a first set of holograms and the coupler may include a second set of holograms. The first set of holograms may be characterized by a first set of selectivity curves having first primary lobes. The second set of holograms may be characterized by a second set of selectivity curves having second primary lobes that overlap the first primary lobes. This may configure the holographic element to narrow the second selectivity curves by diffracting some of the light out of the optical path, thereby optimizing the resolution of images in the light provided to the eye box.

The present invention features VHOEs with expanded acceptance angle ranges as well as various systems and methods for fabricating VHOEs with expanded acceptance angle ranges. The VHOE with expanded acceptance angle range may include two or more individual Bragg gratings. In preferred embodiments, the two or more individual Bragg gratings have the same diffraction geometry but with shifted Bragg conditions. Having the same diffraction geometry means when light is incident on the VHOE including two or more individual Bragg gratings, the diffracted light from each of the Bragg gratings is co-linear or overlapping with the diffracted light from the other Bragg gratings. The Bragg condition for each of the Bragg gratings are shifted with respect to each neighboring Bragg grating by an amount up to the acceptance angle range of each individual Bragg grating.

A lightguide includes an incoupler configured to receive light emitted from a microdisplay and to direct the received light into the lightguide, a first non-planar major surface and a second non-planar major surface configured to reflect the light directed into the lightguide by the incoupler, and an outcoupler comprising a non-planar, angle selective hologram configured to receive light reflected from at least one of the first major surface and the second major surface and to selectively direct the light out of the lightguide based on the angle of incidence at the hologram.

A light projection apparatus is provided comprising: a source of light; a switchable grating on a first substrate; and a diffractive optical element. Light is diffracted at least once by the switchable grating and is diffracted at least once by the DOE.