A method for producing a volume hologram with at least one first area in a first color and at least one second area in a second color includes, providing a volume hologram layer made of a photopolymer; arranging a master with a surface structure on the volume hologram layer; exposing the master using coherent light, wherein light which is incident on at least one first partial area of the surface of the master is diffracted or reflected in the direction of the at least one first area of the volume hologram layer and light which is incident on at least one second partial area of the surface of the master is diffracted or reflected in the direction of the at least one second area of the volume hologram, and wherein the light diffracted or reflected by the first and second partial areas differs in at least one optical property.

A holographic display apparatus capable of providing an expanded viewing window and a display method are provided. The holographic display apparatus includes an image processor configured to provide computer generated hologram (CGH) data to a spatial light modulator, wherein the image processor is further configured to generate a hologram data array comprising information of the holographic image to be reproduced at the first resolution or a resolution less than the first resolution, perform an off-axis phase computation on the hologram data array at the second resolution, and then, generate the CHG data at the first resolution.

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.

An apparatus and method to produce a hologram of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the object from the captured image.

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.

A method includes selecting a period for a volume Bragg grating (VBG) such that a spectral selectivity of the VBG is at least as wide as a spectral width of a broadband light beam that is to be spatially transformed, selecting a desired beam transformation for the broadband light beam, passing a first light beam from a recording light source through an optical device to a volume holographic recording medium where the optical device is configured to induce the desired beam transformation, directing a second light beam from the recording light source to the recording medium, and converging the first light beam and the second beam at a recording angle such that a spatial refractive index modulation profile is recorded in the recording medium that provides the VBG with the selected period, and a phase profile is embedded in the VBG that induces the desired beam transformation for each spectral component within a spectral width of the VBG.

A method for displaying a modified phase mask on a spatial light modulator (SLM), including: modifying, by a processor, a phase mask by combining the phase mask with a virtual lens pattern, the virtual lens pattern having a focal length; displaying, by the SLM in communication with the processor, the modified phase mask on the SLM; and projecting, by a light source in communication with the processor, the light source through the SLM to form an intensity pattern at a distance from the SLM corresponding to the focal length of the virtual lens pattern, the intensity pattern being based on the phase mask.

According to examples, a phase plate may include a transparent substrate and a photopolymer layer attached to the transparent substrate. The photopolymer layer may adjust a backlight via a phase adjustment and focusing. The phase plate may focus a plurality of red, green, and blue components of the backlight onto respective red, green, and blue subpixels of a thin-film-transistor (TFT) layer deposited thereon. A distance between the photopolymer layer of the phase plate and the plurality of red, green, and blue subpixels of the thin-film-transistor (TFT) layer may be in a range from about 200 μm to about 500 μm. In some examples, the phase plate may be part of a liquid crystal display (LCD) apparatus along with a red, green, blue (RGB) laser to provide backlight; a grating light guide to transmit the backlight; and a liquid crystal display (LCD) layer on the thin-film-transistor (TFT) layer.

A phase and phase/amplitude spatial light modulator arrangement for generating a complex-valued light field with a spatial light modulator, a phase element and an optical system. The phase and amplitude spatial light modulator arrangement is configured to generate a light field that is adjustable in amount and phase. A method realizes operation of a combined spatial light modulator for generating a complex-valued light field. Here, the method includes adapting an optical characteristic in several areas of a phase element. A further method realizes operation of an optical arrangement for modulating different light wavelengths by adjusting several wave influences in several areas of a phase modulator. A last method realizes operation of an optical arrangement by adjusting an amplitude spatial light modulator for modulating light intensities in at least two optical paths.

An optical phase grating produces an interference pattern rich in intensity and spatial-frequency information from the external scene. The grating includes an odd number of repeated sets of adjacent horizontal portions, separated by steps, that fill an area that radiates outward from a central region. At a given distance from the central region and within the area of the phase grating, each of the first horizontal portions is of a first width that differs from a second width of the adjacent second horizontal portions. The interference patterns produced by the grating can be processed to extract images and other information of interest about an imaged scene.