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.

The present disclosure provides methods and systems for the three-dimensional (3D) printing of 3D objects. Methods and systems provided herein may comprise 3D holographic lithography which may enable the 3D printing of various shapes. Methods and systems provided herein may enable high efficiency 3D holographic printing and may avoid, for example, problems zero-order defects. Methods and systems provided herein comprise methods for printing 3D objects with reduced or minimal inconsistency.

A three-dimensional (3D) display system includes a reference spatial light modulator configured to generate a reference wavefront. The system also includes an object spatial light modulator configured to generate an object wavefront. The system further includes a Hogel basis display positioned between the reference spatial light modulator and the object spatial light modulator. The Hogel basis display is configured to receive the reference wavefront and the object wavefront. The Hogel basis display is also configured to generate a light field based at least in part on interference between the reference spatial light modulator and the object spatial light modulator.

There is provided a holographic projector comprising a reflective liquid crystal display device. The reflective liquid crystal display device comprises a light-modulating layer between a first substrate and a second substrate substantially parallel to the first substrate. The light-modulating layer comprises planar-aligned nematic liquid crystals having positive dielectric anisotropy. The first substrate is substantially transparent and comprises a first alignment layer arranged to impart a first pre-tilt angle θ.sub..Math. on liquid crystals proximate the first substrate, wherein θ.sub.1>5°. The second substrate is substantially reflective and comprises a second alignment layer arranged to impart a second pre-tilt angle Θ.sub.2 on liquid crystals proximate the second substrate, wherein θ.sub.2>5°. The reflective liquid crystal display device further comprises a plurality of pixels defined on the light-modulating layer having a pixel repeat distance x, wherein x≤10 μm. The distance d between inside faces of the first substrate and second substrate satisfies 0.5 μm≤d≤3 μm, and the birefringence of the liquid crystal Δη≥0.20. The holographic projector further comprises a display driver arranged to drive the reflective liquid crystal display device to display a hologram by independently-driving each pixel at a respective modulation level selected from a plurality of modulation levels having a phase modulation value.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

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.

A compound metaoptic is presented. The compound metaoptic is comprised of at least two phase-discontinuous metasurfaces, which can convert an incident light beam to an aperture field with a desired magnitude, phase, and polarization profile. Each of the constitutive metasurfaces is designed to exhibit specific refractive properties, which vary along the metasurface. Furthermore, due to its transmission-based operation, the metaoptic can operate without lenses and be low profile: potentially having a thickness on the order of a few wavelengths or less. A systematic design procedure is also presented, which allows conversion between arbitrary complex-valued field distributions without reflection, absorption or active components. Such compound metaoptics may find applications where a specific complex field distribution is desired, including displaying holographic images and augmented or virtual reality systems.

A spatial light modulator and a liquid-crystal module are provided. The spatial light modulator includes a first liquid-crystal module and a second liquid-crystal module that are arranged opposite to each other. The first liquid-crystal module includes a first array substrate, a first color filter substrate, and a plurality of first spacers disposed therebetween. The second liquid-crystal module includes a second array substrate, a second color filter substrate, and a plurality of second spacers disposed therebetween. The first array substrate, the first color filter substrate, the second color filter substrate, and the second array substrate are stacked sequentially. At least one first spacer forms a first overlapped unit, and at least one second spacer forms a second overlapped unit. An orthographic projection of the first overlapped unit on the first array substrate fully overlaps an orthographic projection of the second overlapped unit on the first array substrate.

A spatial light modulator and a liquid-crystal module are provided. The spatial light modulator includes a first liquid-crystal module and a second liquid-crystal module that are arranged opposite to each other. The first liquid-crystal module includes a first array substrate, a first color filter substrate, and a plurality of first spacers disposed therebetween. The second liquid-crystal module includes a second array substrate, a second color filter substrate, and a plurality of second spacers disposed therebetween. The first array substrate, the first color filter substrate, the second color filter substrate, and the second array substrate are stacked sequentially.