The disclosed subject matter provides systems and methods for spatial and spectral modulation of light. An example system for modulating light can include a substrate and a plurality of meta units, coupled to the substrate and configured to spatially and spectrally modulate the light, wherein the plurality of meta units includes a perturbation and forms a perturbed lattice supporting a quasi-bound state in the continuum.

Devices utilizing holographic 4D plenoptic capture and display technologies to generate a light field function to provide glasses-less vision correction for observers with imperfect vision, and to project an image according to the generated light field function, and methods for calibrating a four-dimensional light field for a user with an uncorrected visual acuity.

A video communication system uses a light field display to present a holographic image of a remote scene (e.g., a hologram of a remote participant). The system may include a local light field display assembly and a controller. The controller generates display instructions based on visual data corresponding to a remote scene received from a remote image capture system (e.g., a remote light field display system). The display instructions cause the local light field display assembly to generate a holographic image of the remote scene.

Dual or multi-modulation display system are disclosed that comprise projector systems with at least one modulator that may employ non-mechanical beam steering modulation. Many embodiments disclosed herein employ a non-mechanical beam steering and/or polarizer to provide for a highlights modulator.

A generation method of a digital hologram includes steps of emitting coherent light from a coherent light source, imaging a hologram that is an interference pattern of an object beam and a reference beam due to the emission light from the light source, and setting a plurality of wavelengths of the illumination light that generates the hologram detected by the detector, and wherein the plurality of wavelength are specified by the wavelength setting step based on a magnification percentage X of a conjugate image set up by a user not to disturb visibility of an image when a real image and the conjugate image reconstructed by a predetermined calculation means relative to structures of observation targets are superimposed to a corresponding real image so that a shortest wavelength λ.sub.min and a longest wavelength λ.sub.max satisfy the expression λ.sub.max/λ.sub.min≧(1/X+1).

There is disclosed herein a display device comprising a picture generating unit, a waveguide pupil expander and a viewer-tracking system. The picture generating unit comprises a first display channel, a second display channel and a controller. The first display channel is arranged to output first spatially-modulated light of a first colour. The first spatially-modulated light corresponds to a first picture. The second display channel is arranged to output second spatially-modulated light of a second colour. The second spatially-modulated light corresponding to a second picture. The controller is arranged to drive the first display channel and second display channel. The waveguide pupil expander comprises a pair of parallel reflective surfaces. The waveguide pupil expander defines an input port and a viewing window. The input port is arranged to receive the first spatially-modulated light and the second spatially-modulated light. The viewing window is an area or volume within which a viewer may view the first picture and the second picture. The pair of parallel reflective surfaces is arranged to guide the first spatially-modulated light and the second spatially-modulated light from the input port to the viewing window by a series of internal reflections. The reflectivity of a first reflective surface of the pair of parallel reflective surfaces is provided by a graded coating. The graded coating is partially transmissive to light of the first colour and light of the second colour. The transmissivity of the graded coating is non-achromatic. The viewer-tracking system is arranged to determine a viewing position within the viewing window. The controller is arranged to maintain as substantially constant the colour balance of the first and second picture as seen from the viewing position based on the viewing position determined by the viewer-tracking system.

Methods, systems and computer program products for performing visual quality assessment using holographic interferometry are provided. Aspects include obtaining a reference holographic pattern based on a reference object and obtaining a test holographic pattern based on a test object. Aspects also include creating an interference pattern by superimposing the test holographic pattern onto the reference holographic pattern. Aspects further include determining a difference between the reference object and the test object based upon the interference pattern.

An ultrasonic apparatus (100) for creating a holographic ultrasound field (1) comprises an ultrasound source device (10) being adapted for creating an ultrasound wave, and a transmission hologram device (20) having a transmission hologram (21) and an exposed acoustic emitter surface (22), said transmission hologram device (20) being acoustically coupled with the ultrasound source device (10) and being arranged for transmitting the ultrasound wave through the acoustic emitter surface (22) and creating the holographic ultrasound field in a surrounding space, wherein the acoustic emitter surface (22) is a smooth surface which do not influence the field distribution of the ultrasound wave. Furthermore, a method of creating a holographic ultrasound field in an object (3), wherein the ultrasonic apparatus (100) is used, and applications of the ultrasonic apparatus (100) are described.

A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

A holographic weapon sight with a housing that has a viewing end and an opposing target end. The viewing path is defined from the viewing end to the target end. The sight has a light source that projects a light beam along a path. The sight also has a diffractive optical element (DOE) disposed in the path of the light beam, and the DOE reconstructs an image of a reticle. The sight includes a parabolic reflector that reflects the image of the reticle. The parabolic reflector may be disposed in the viewing path such that a user views a target along the viewing path through the parabolic reflector from the viewing end.