A tunable-liquid-crystal-grating-based holographic true 3D display system comprises a laser, a filter, a beam expander, a semi-transparent semi-reflective mirror, a spatial light modulator, a lens I, a diaphragm, a tunable liquid crystal grating, a polaroid, a signal controller, a lens II and a receiving screen. The laser, the filter and the beam expander are used for generating collimated incident light. The spatial light modulator is loaded with a hologram of a 3D object. The diaphragm is positioned behind the lens I for eliminating a high-order diffracted light in the holographic true 3D display. The tunable liquid crystal grating is located on the back focal plane of the lens I and on the front focal plane of the lens II, and the signal controller is used for synchronously controlling the voltage of the tunable liquid crystal grating and the generation and loading of the hologram.

Various embodiments set forth optical patterning systems. Each pixel of the optical patterning systems includes an amplitude-modulating cell that is in line with a phase-modulating cell. The amplitude-modulating cell includes a liquid crystal and a drive method for modulating at least the amplitude of a wavefront of light that passes through the amplitude-modulating cell. The phase-modulating cell includes a liquid crystal and a drive method for modulating at least the phase of a wavefront of light that passes through the phase-modulating cell. In some embodiments, the amplitude-modulating cell shares a common ground with the phase-modulating cell. The amplitude-modulating cell and the phase-modulating cell can be used to independently control the amplitude change and phase delay imparted by the pixel, enabling complex wavefront modulation.

A hologram display device includes a light source unit that emits light, a spatial light modulator that modulates the light emitted from the light source unit, and a random pinhole panel. The random pinhole panel includes a plurality of pinholes of a random position or a random size and is arranged in line with an output part of the spatial light modulator. In the hologram display device and the method of manufacturing the hologram display device, a position and size of a random pinhole on the random pinhole are not limited to inside each pixel of the spatial light modulator.

A gating and a 3D holographic display device are provided. The grating includes grating electrodes and spacing pillars disposed between a first substrate and a second substrate opposite to the first substrate. The grating electrodes extend along a first direction and are arranged along a second direction. Along a plane parallel to the first substrate, positions of spacing pillars are referred to as matrix points. The spacing pillars correspond to the matrix points; the matrix points include multiple first matrix point units arranged as an array. A minimum repeating unit of the matrix points includes four first matrix point units located at four vertices of a first quadrilateral. Two adjacent sides of the first quadrilateral are defined as a first unit vector and a second unit vector, respectively; and an angle between the first unit vector and the second unit vector is α1, and 0°≤α1≤90°.

A gating and a 3D holographic display device are provided. The grating includes grating electrodes and spacing pillars disposed between a first substrate and a second substrate opposite to the first substrate. The grating electrodes extend along a first direction and are arranged along a second direction. Along a plane parallel to the first substrate, positions of spacing pillars are referred to as matrix points. The spacing pillars correspond to the matrix points; the matrix points include multiple first matrix point units arranged as an array. A minimum repeating unit of the matrix points includes four first matrix point units located at four vertices of a first quadrilateral. Two adjacent sides of the first quadrilateral are defined as a first unit vector and a second unit vector, respectively; and an angle between the first unit vector and the second unit vector is α1, and 0°≤α1≤90°.

Disclosed is a holographic display including a spatial light modulator (SLM) with pixels, the SLM pixels being on a substrate, the SLM including circuitry which is on the same substrate as the SLM pixels, the circuitry operable to perform calculations which provide an encoding of the SLM.

A direct-retina holographic projection system includes first and second spatial light modulators (SLMs) and a control module. The first SLM receives a beam of light and dithers the beam of light at a predetermined frequency to provide multiple instances of the beam of light. The second SLM receives the instances of the beam of light, displays an encoded phase hologram of a graphic image to be projected, and diffracts the instances of the beam of light to provide instances of the encoded phase hologram with the same graphic image but multiplied with dithered wavefronts. The control module: iteratively adjusts a parameter of the first SLM to generate the instances of the beam of light; and controls operation of the second SLM to, based on the instances of the beam of light, display multiple instances of the graphic image on a retina of an eye of a viewer.

A display apparatus includes a coherent light source, a display unit, a light-diffusing element, and at least one optical element. The coherent light source is configured to provide coherent light beams. The display unit is configured to form a three-dimensional image beam based on interference of the coherent light beams, wherein the three-dimensional image beam is imaged on an intermediate imaging surface after passing through the display unit. The light-diffusing element is located on the intermediate imaging surface, wherein a diffusion angle of the three-dimensional image beam is sequentially changed by passing through the light-diffusing element. The at least one optical element is located on a transmission path of the three-dimensional image beam from the light-diffusing element, and is configured to project the three-dimensional image light beam passing through the display unit out of the display apparatus to display a three-dimensional image.

Disclosed is an apparatus for displaying a hologram including a pixel circuit array including first to n.sup.th pixel circuits, a first insulating layer provided on the pixel circuit array, first to n.sup.th pixel electrodes provided on the first insulating layer and electrically connected to the first to n.sup.th pixel circuits, respectively, a second insulating layer provided on the first insulating layer, first to n.sup.th display electrodes provided on the second insulating layer and electrically connected to the first to n.sup.th pixel electrodes, respectively, a display panel formed on the first to n.sup.th display electrodes, and a common electrode formed on the display panel. The first to n.sup.th display electrodes are clustery formed, and an area of the first to n.sup.th display electrodes is smaller than an area of the pixel circuit array.

A tunable liquid crystal (LC) device includes an LC layer between a pair of reflectors forming an optical cavity. The reflectors include conductive layers for applying an electrical signal to the LC layer. One of the conductive layers may include an array of conductive pixels for spatially selective control of the effective refractive index of the LC layer. The phase delay introduced by the LC layer may be greatly increased or magnified by placing the LC layer into the optical cavity. This enables a substantial reduction of the LC layer thickness, which in its turn enables very tight pitches of the LC pixels, with a reduced inter-pixel crosstalk caused by fringing electric fields, as well as faster switching times. A tight-pitch, fast LC device may be used as a configurable hologram or a spatial light modulator.