A holographic display device is provided, comprising a spatial light modulator. The spatial light modulator is configured to load at least one composite hologram, and one of the at least one composite hologram is formed by superposing N sub-holograms. The holographic display device further comprises a light source arranged on a light incoming side of the spatial light modulator. The light source is configured to provide readout light to the spatial light modulator. The light source comprises M light source components. The direction of propagation of emergent light of each of at least two light source components among the M light source components is identical to the direction of propagation of a reference wave corresponding to one of the N sub-holograms, wherein MN2, and M and N are positive integers.

Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.

Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.

Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.

In one embodiment, a color holographic image is created by generating a separate complex hologram for each of multiple different colors of an object field illuminated with incoherent light, combining the separate complex holograms to obtain a color complex hologram, and generating a reconstructed color holographic image of the object field.

The present disclosure relates to a holographic reproducing apparatus comprising: a light source configured to supply a reproducing light beam to be incident to a photorefractive crystal, wherein the photorefractive crystal has holographic images recorded therein in a plurality of different angles respectively; a reflective mirror configured to reflect the reproducing light beam emitted from the light source to the photorefractive crystal; and a driving mechanism connected to the reflective mirror and configured to drive the reflective mirror to move on a plane elliptical arc, the plane elliptical arc is defined by using the light source and the photorefractive crystal as two mathematical focuses and using a predetermined constant, so that an incident angle of the reproducing light beam to be incident to the photorefractive crystal varies to form a plurality of reproducing light beams in different angles to be incident to the photorefractive crystal in sequence.

A device in holographic imaging comprises: at least two light sources, wherein each of the at least two light sources is arranged to output light of a unique wavelength; and at least one holographic optical element, wherein the at least two light sources and the at least one holographic optical element are arranged in relation to each other such that light from the at least two light sources incident on the at least one holographic optical element interacts with the at least one holographic optical element to form wavefronts of similar shape for light from the different light sources.

Embodiments of the present disclosure provide a holographic display device. The holographic display device includes a spatial light modulator and a light source unit. The light source unit is provided on the light entry side of the spatial light modulator and configured to providing read-out light to the spatial light modulator. The spatial light modulator includes at least one loading portion for receiving a write-in signal, which comprises a plurality of pixel units arranged in a matrix form, and the light exit surface of at least a part of which is a first cambered surface protruding in a direction away from the light source unit.

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.