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 device and a method for manufacturing holographic optical elements. The device includes at least two partial light beams and one interference light beam, one deformable mirror in each case per partial light beam, a control unit, which is configured to actuate the deformable mirrors to adapt a wavefront of the partial light beam, and a holographic film. The deformable mirrors are situated so as to each reflect precisely one partial light beam and to direct the reflected partial light beam on the holographic film, and the interference light beam being directed on the holographic film to interfere with the reflected partial light beams so as to simultaneously generate at least two holographic optical elements.

An exposure device for recording a hologram. The exposure device includes at least one modulation unit, which is designed to generate a modulation beam representing a reference beam and/or an object beam by impressing a modulation representing at least one holographic element of the hologram onto a laser beam. The exposure device also includes at least one reduction unit, which is designed to generate a modified modulation beam using the modulation beam, the modified modulation beam having a smaller beam diameter than the modulation beam. The exposure device further includes at least one objective lens unit, which is designed to direct the modified modulation beam through an immersion medium onto a recording material in order to record the hologram by exposing the recording material to the modified modulation beam.

An optical device for forming a distribution of a three-dimensional light field comprises: an array of individually addressable unit cells; each unit cell in the array of unit cells comprising a stack including: at least one electrode; and a resonance defining layer, comprising at least a phase change material, PCM, layer, wherein the resonance defining layer is patterned to define a geometric structure dimensioned for defining a wavelength-dependent in-plane resonance of an electromagnetic wave; wherein the at least one electrode causes a phase change of the phase change material based on receiving a control signal to alter a wavelength-dependency of resonance in the resonance defining layer for controlling the optical property of the unit cell; wherein unit cells in the array of unit cells are separated such that the PCM layer of a unit cell is separated from the PCM layer in an adjacent unit cell.

A printing device (106) includes a laser source and a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator). The printing device generates a laser control signal and a LCOS-SLM control signal. The laser source (110) generates a plurality of incident laser beams based on the laser control signal. The LCOS-SLM (112) receives the plurality of incident laser beams, modulates the plurality of incident laser beams based on the LCOS-SLM control signal to generate a plurality of holographic wavefronts (214,216) from the modulated plurality of incident laser beams. Each holographic wavefront forms at least one corresponding focal point. The printing device cures a surface layer or sub-surface layer (406) of a target material (206) at interference points of focal points of the plurality of holographic wavefronts. The cured surface layer of the target material forms a three-dimensional printed content.

A display system comprising a first plurality of pixels, a second plurality of pixels, a first Fourier transform lens and a second Fourier transform lens. The first plurality of pixels is arranged ranged to display first holographic data corresponding to a first holographic reconstruction and receive light of a first wavelength. The a second plurality of pixels is arranged to display second holographic data corresponding to a second holographic reconstruction and receive light of a second wavelength. The first Fourier transform lens is arranged to receive spatially modulated light having a first wavelength from the first plurality of pixels and perform an optical Fourier transform of the received light to form the first holographic reconstruction at a replay plane, wherein the first holographic reconstruction is formed of light at the first wavelength. The second Fourier transform lens is arranged to receive spatially modulated light having a second wavelength from the second plurality of pixels and perform an optical Fourier transform of the received light to form the second holographic reconstruction at the replay plane, wherein the second holographic reconstruction is formed of light at the second wavelength. The optical path length from the first Fourier transform lens to the replay plane is not equal to the optical path length from the second Fourier transform lens to the replay plane.

Embodiments of the present disclosure include apparatuses and method for a stacked light emitting diode (LED) hologram display. A stacked LED hologram display can include a first array of LEDs that are configured to emit red light received by a meta-optics panel configured to display a first portion of a holographic image, a second array of LEDs that are configured to emit green light received by a meta-optics panel configured to display a second portion of a holographic image, and a third array of LEDs that are configured to emit blue light received by a meta-optics panel configured to display a third portion of a holographic image. The stacked LED hologram display can include a number of actuators configured to adjust a position of a first array of LEDs in first direction and a second direction, adjust a position of a second array of LEDs in the first direction and the second direction, and adjust a position of a third array of LEDs in the first direction and the second direction.

An interference imaging device includes a light interference generator that includes: a light wave splitter configured to reflect a part of incident light and to allow a remaining part of the incident light to pass through; a phase modulator configured to modulate a phase of incident light that has passed through the light wave splitter; and a reflector configured to reflect the phase-modulated incident light from the phase modulator so that the reflected, phase-modulated incident light overlaps with incident light that has been reflected by the light wave splitter.

An apparatus and method for recording a holographic optical element. The apparatus includes a first recording unit configured to provide a first wave front for recording the holographic optical element, a second recording unit configured to provide a second wave front for recording the holographic optical element, and (i) a deformable phase plate configured to perform wave front modulation of the first wave front when the holographic optical element is recorded, or (ii) a plurality of deformable phase plates, at least one deformable phase plate (of the plurality of deformable phase plates can be configured to perform wave front modulation of the first wave front when the holographic optical element is recorded.

A method for generating a holographic image, a signal processor, a holographic image display device, a wearable apparatus, and an onboard head-up display apparatus. The method comprises: performing holographic transformation on the basis of a target amplitude phase distribution of a target image to obtain a holographic phase image; performing phase quantization of the holographic phase image to obtain a quantized holographic image; performing inverse holographic transformation of the quantized holographic image to obtain a reconstructed image; if the reconstructed image satisfies a preset condition, determining that the quantized holographic image is a target holographic image; if not, constraining the amplitude phase of the reconstructed image and, on the basis of the amplitude phase constrained image, continuing iteration. The present method can rapidly and effectively implement monochrome or multi-colour high contrast ratio, low noise real-time holographic image generation and display, and the imaging distance can be freely adjusted.