The present disclosure relates to a holographic display device and an electronic device. The holographic display device may include a light source, a light transmission structure, a first photonic crystal group, and a spatial light modulator. The light transmission structure has a light incident surface and a light exiting surface. The first photonic crystal group is disposed between the light incident surface and the light source. The first photonic crystal group includes various photonic crystals for dividing light emitted by the light source into light beams of different colors. The light beams of different colors are transmitted into the light transmission structure through the light incident surface and emitted through the light exiting surface. The spatial light modulator corresponds to the light exiting surface for modulating light beams of different colors emitted from the light exiting surface to form a holographic image.

A method for displaying an image viewable by an eye, the image being projected from a portable head worn display, comprises steps of: emitting a plurality of light beams of wavelengths that differ amongst the light beams; directing the plurality of light beams to a scanning mirror; modulating in intensity each one of the plurality of light beams in accordance with intensity information provided from the image, whereby the intensity is representative of a pixel value within the image; scanning the plurality of light beams in two distinct axes with the scanning mirror to form the image; and redirecting the plurality of light beams to the eye using a holographic optical element acting as a reflector of the light beams, whereby the redirecting is dependent on the wavelength of the light beam, to create for each light beam an exit pupil at the eye that is spatially separated from the exit pupils of the other light beams.

A device for determining a 3D structure of an object having first and second laser emitters which generate laser radiation with first and second different wavelengths, respectively. A first beam splitter splits the laser radiation of each laser emitter into reference and illuminating radiation. The illuminating radiation is adapted to impinge on the object to be measured, be reflected by the object as object radiation, and interfere with the reference radiation to form interference patterns. A detector receives the interference patterns. A selection hologram deflects object radiation which impinges on it within a predefined incidence angle range and passes object radiation which impinges on it outside of the incidence angle range undiffracted. The undiffracted radiation either passes by the determination area of the detector or impinges on the determination area at an angle outside the determination angle range.

A method of generating a color image of a sample includes obtaining a plurality of low resolution holographic images of the sample using a color image sensor, the sample illuminated simultaneously by light from three or more distinct colors, wherein the illuminated sample casts sample holograms on the image sensor and wherein the plurality of low resolution holographic images are obtained by relative x, y, and z directional shifts between sample holograms and the image sensor. Pixel super-resolved holograms of the sample are generated at each of the three or more distinct colors. De-multiplexed holograms are generated from the pixel super-resolved holograms. Phase information is retrieved from the de-multiplexed holograms using a phase retrieval algorithm to obtain complex holograms. The complex hologram for the three or more distinct colors is digitally combined and back-propagated to a sample plane to generate the color image.

A method for performing color image reconstruction of a single super-resolved holographic sample image includes obtaining a plurality of sub-pixel shifted lower resolution hologram images of the sample using an image sensor by simultaneous illumination at multiple color channels. Super-resolved hologram intensity images for each color channel are digitally generated based on the lower resolution hologram images. The super-resolved hologram intensity images for each color channel are back propagated to an object plane with image processing software to generate a real and imaginary input images of the sample for each color channel. A trained deep neural network is provided and is executed by image processing software using one or more processors of a computing device and configured to receive the real input image and the imaginary input image of the sample for each color channel and generate a color output image of the sample.

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 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.

A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes obtaining information about an object existing in the external environment based on the output signal light.

A device for detecting at least one object present in a sample, the device including a light source to emit at least one incident wave at a wavelength λ, a detection volume intended to receive the object, and to receive at least one incident wave, an image sensor positioned to receive at least one scattered light wave obtained by diffraction of the incident wave on the object and a reference wave from the source and not diffracted on the object and to generate a holographic image, and a computer data processing device to digitally reconstruct the object based at least on the holographic image and the wavelength λ. The device also comprises a support comprising patterns organized to form at least one diffraction grating, the grating being periodic and having a pitch P, such that λ/2≤P≤2λ.

Example embodiments relate to imaging devices for in-line holographic imaging of objects. One embodiment includes an imaging device for in-line holographic imaging of an object. The imaging device includes a set of light sources configured to output light in confined illumination cones. The imaging device also includes an image sensor that includes a set of light-detecting elements. The set of light sources are configured to output light such that the confined illumination cones are arranged side-by-side and illuminate a specific part of the object. The image sensor is arranged such that the light-detecting elements detect a plurality of interference patterns. Each interference pattern is formed by diffracted light from the object originating from a single light source and undiffracted light from the same single light source. At least a subset of the set of light-detecting elements is arranged to detect light relating to not more than one interference pattern.