An illumination device is provided, including a coherent light source that emits coherent light beam and an optical device that diffuses the coherent light beam. The optical device includes a first diffusion region that diffuses the coherent light beam to illuminate a first area, and a second diffusion region that diffuses the coherent light beam to display predetermined information in a second area. A timing control unit individually controls a light emission timing at which the coherent light source emits the coherent light so that the coherent light is irradiated to the first diffusion region and the second diffusion region, an incident timing at which the coherent light from the coherent light source is incident on the first diffusion region and the second diffusion region, or an illumination timing at which the coherent light diffused by the optical device illuminates the first area and the second area.

A display method lets a display beam to propagate in a transparent substrate while internally reflected repeatedly and lets the display beam partly emit out of the transparent substrate every time the display beam is internally reflected, thereby emitting display beams from almost entirety of a surface of the transparent substrate. The display beam is produced holographically. A display apparatus includes a spatial phase modulator that produces a display beam, a transparent substrate in which the display beam is internally reflected repeatedly to propagate in it, and a splitter that lets the display beam partly emit out of the transparent substrate every time the display beam is internally reflected.

Provided is an apparatus and method for encoding a hologram and evaluating a holographic image quality for an amplitude-modulated hologram. A hologram encoding method may include acquiring three-dimensional (3D) information of a scene or an object; generating hologram information based on the 3D information; deriving a real number hologram function by extracting a real number part and an imaginary number part from the hologram information; determining an intermediate hologram function based on a sign characteristic of the real number hologram function; and determining encoded hologram information based on the intermediate hologram function.

Provided are methods and devices for data superimposition, in which an imaging device comprises a diffuser and a holographic layer to provide a real or virtual image for an observer. In one variant, diffuser and holographic layer are provided on different sides of a transparent carrier. In other embodiments, the imaging device and holographic layer are arranged in smart glasses.

A holographic imaging device includes a laser device, a laser beam expanding and collimating system and a liquid crystal cell. The laser beam expanding and collimating system is configured to expand a light beam from the laser device and enable the expanded light beam to be transmitted substantially vertically to the liquid crystal cell. An amplitude-transmission coefficient distribution of the liquid crystal cell is determined in accordance with a brightness distribution of holographic interference fringes of an object to be displayed.

In the present invention, by providing an apparatus for displaying a complex modulated holograph and including a light source configured to output light, a display configured to display the hologram by diffracting the output light through a plurality of pixels, and a processor configured to control the display to obtain complex hologram data corresponding to the hologram, and modulate the output light based on the complex hologram data and device information of the plurality of pixels, it is possible to modulate amplitude information and phase information of the light source into required values and display a complex hologram, and to remove a noise component of the hologram.

The present disclosure provides an optical modulation device, an optical modulation method and a holographic display apparatus. The optical modulation device is configured to perform optical modulation of a light beam and comprising: an amplitude modulator, configured to perform amplitude modulation of the light beam based on amplitude information in complex amplitude information of each pixel of a digital hologram; an optical scanning assembly, configured to scan the light beam within a predetermined range; a phase modulator, configured to perform phase modulation of the light beam based on phase information in the complex amplitude information.

A method of structured illumination digital holography includes: (a) providing a structured illumination generating unit and binarization random number encoding unit to generate a coded structured illumination pattern; (b) sampling at least two patterns with phase shift which synthesized as a single structured illumination pattern to be encoded; (c) forming a single digital hologram, and wavefront reconstructing the single digital hologram; (d) performing a compressive sensing approach to recover the object wave with at least two phase shift patterns; and (e) reconstructing the separation of overlap spectrum, to obtain an image covering bandpass spectrum with different high frequency and low frequency.

A method for directing non-modulated light from a Spatial Light Modulator (SLM) and allowing through modulated light for producing an interference based holographic image, the method including illuminating the SLM with coherent light, thereby producing a mix of light modulated by the SLM and light not modulated by the SLM, and projecting the mix of the modulated light and the not modulated light along an optical axis onto a volume grating, wherein the volume grating directs the not modulated light away from the holographic image and allows through modulated light for producing the holographic image. Related apparatus and methods are also described.

A holographic image display device includes a backlight for emitting light. An optical path adjuster includes a plurality of electrowetting prisms. Each of the plurality of electrowetting prisms is configured to adjust an optical path of the light. A spatial light modulator includes a plurality of pixels. Each of the plurality of pixels is configured to modulate an amplitude or a phase of the light.