An optical track format of a holographic storage optical disc includes a lead-in area, a data area and a lead-out area. The data area is provided with data holographic positioning marks for marking reading/writing position of data holograms on the optical track and start positioning marks for marking position on the optical track where data holograms start to be recorded. The start positioning marks may also contain address encoding information. Such optical track can be encoded by performing binary encoding by length of the optical track between two consecutive notches, or performing binary encoding by high and low levels of a level signal.

An infrared imaging signal is generated to illuminate tissue. An infrared image of an exit signal of the infrared imaging signal is captured. The infrared imaging signal is within a frequency band.

In one embodiment, a device transmits data characterizing a holographic image to a physical environment. A visible rendering of the holographic image is created in the physical environment. The device uses a reasoning engine to make an inference regarding a state of the physical environment based on sensor data captured in the physical environment indicative of one or more real-time characteristics of the physical environment. In response to the inference, the device adjusts the holographic image. Then, the device transmits data characterizing the adjusted holographic image to the physical environment, and a visible rendering of the adjusted holographic image is created in the physical environment.

A new diversity concept is provided for achieving accurate phase retrieval with a singleshot acquisition. Multiple irradiance data are obtained by a diffractive grating or CGH designed to generate multiple diffraction orders with different diversity values. The effective filters associated with the individual diffraction orders from the diffractive grating or CGH are calculated. The effective filters are extracted by numerical propagation, and they preferably include both real and imaginary values, which signify both absorption and phase shift versus position in the filter plane. The reconstruction process utilizes accurate knowledge of the effective filters for each diffraction order for high quality reconstruction of the extrinsic phase.

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.

In an approach to security for displayed confidential holographic objects, one or more computer processors receive a request from a user to display a holographic object in association with a device. One or more computer processors identify content to be moved to the holographic object. One or more computer processors determine the content includes confidential information. One or more computer processors request authentication from the user. One or more computer processors receive the authentication from the user. One or more computer processors create a holographic boundary, where the holographic boundary blocks a view of the holographic object from one or more unauthorized users. One or more computer processors display the holographic boundary. One or more computer processors display the holographic object in association with the device.

Exemplary arrangements relate to methods for recording and reproducing holograms. A method of recording a hologram in a thresholded opto-magnetic medium (7) includes producing a collimated recording beam (1) with a pulsed laser. The intensity of the recording beam is selectively modulated by passage through a modulator (2). The recording beam is spatially shaped by passage through a shaping element (15). The shaped modulated recording beam is made convergent by passage through an aspheric lens (4). The convergent beam is deflected bidirectionally with a MEMS mirror (6) that is in operative connection with the modulator, such that multiple disposed locations on a surface of the medium are exposed to a constriction of the convergent shaped recording beam, causing a change in the medium in the locations. Reconstructing the hologram is carried out by illuminating the medium with a collimated laser beam and focusing with a lens, light from the illuminated medium onto a detection matrix. Additional methods of recording and reproducing holograms utilize alternative steps.

Systems and methods of determining a hologram of an image for a system comprising a display device and viewing system are disclosed. Some embodiments implement a multi-stage procedure comprising (i) determining a first complex light field at an entrance pupil of the viewing system, (ii) determining a second complex light field at a sensor plane of a sensor of the viewing system, (iii) determining a third complex light field at the entrance pupil, and (iv) determining a fourth complex light field at the display plane. Some embodiments include extracting a hologram from a data set corresponding to the fourth complex light field.

Systems and method disclosed herein include, among other features, receiving an image for display within a display area of a display system, determining a first image component of the image, calculating a hologram of the image, displaying the hologram on a display device and spatially modulating light in accordance with the displayed hologram, and propagating the spatially modulated light through a pupil expander arranged to provide a plurality of different light propagation paths for the spatially modulated light from the display device to the viewing area, wherein each light propagation path corresponds to a respective continuous region of the image owing to the angular distribution of light from the hologram.

A hologram that includes a formation layer and a reflection layer that are laminated. The formation layer has an optical phase modulation structure on a first interface in contact with the reflection layer. When reference light emitted from a point light source enters through a second interface different from the first interface of the formation layer, the entirety or part of an image to be reconstructed by the optical phase modulation structure is reconstructed as spatial information on the point light source side relative to the second interface.