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. A holographic image display apparatus includes: a light source configured to emit light, the light source including a plurality of vertical-cavity surface-emitting lasers (VCSELs) that are spaced apart from one another; a spatial light modulator configured to, based on a hologram data signal, modulate the light emitted by the light source; and a focusing optical system configured to focus an image formed by the spatial light modulator using a Maxwellian view method.

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.

A lighting device for vehicles, in particular a signal light, with a light source for emitting a light beam and an optical unit associated with the light source for producing a predetermined light function, the optical unit having a holographic element and a lens arranged in the main emission direction in front of the holographic element, the holographic element comprising such a diffraction structure that the light beam emitted from the light source onto the holographic element is varied according to a predetermined illumination pattern such that the holographic light beam lights an illumination surface of the lens to generate the light function.

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 backlight unit and a holographic display apparatus including the same are provided. The backlight unit includes a light guide plate and a uniformity changing element. The uniformity changing element has a light-incident surface and a light-exiting surface facing the light-incident surface, and the uniformity changing element receives the light output from the light guide plate through the light-incident surface, changes uniformity of the received light from the light guide plate and outputs the received light with the change in the uniformity of the received light through the light-exiting surface.

An optical system includes an optical lens, a polarization volume hologram (PVH) layer arranged over the optical lens, and an IR absorbing structure arranged between the optical lens and the PVH layer. The PVH layer being configured to reflect infrared (IR) light. The IR absorbing structure includes a quarter-wave plate (QWP) arranged between the optical lens and the PVH layer and a linear absorptive polarizer arranged between the QWP and the optical lens. The linear absorptive polarizer is configured to absorb IR light.

A spatial light modulator (SLM) includes a first liquid crystal panel and a second liquid crystal panel that are oppositely configured, and a polarization adjustment part configured between the first liquid crystal panel and the second liquid crystal panel. An alignment direction of the first liquid crystal panel is parallel to an alignment direction of the second liquid crystal panel. The first liquid crystal panel is configured to perform a phase modulation on incident linear-polarized light. The polarization adjustment part is configured to rotate, by a preset angle, a polarization direction of linear-polarized light exited from the first liquid crystal panel. The second liquid crystal panel is configured to adjust a polarization state of linear-polarized light exited from the polarization adjustment part to adjust an amplitude of exited light.