Electro-holographic light field generator devices comprising surface acoustic wave (SAW) optical modulators are disclosed that employ multiple output couplers. These output couplers might be distributed along waveguides of the SAW modulators, within output coupling regions. Each of these output couplers can be configured for directing an incident leaky mode light at different output angles. In some cases, it may be desirable to employ the output couplers to function as different sub-pixels, to provide light to different viewing directions. The output couplers may be mirrors, volume gratings, chirped gratings, reflection gratings, two dimensional gratings, and/or transmission gratings. The output couplers may be angled so that the coupling output fans for each optical modulator are offset from the waveguide for that optical modulator.

The present disclosure relates to a holographic reproducing apparatus comprising: a light source configured to supply a reproducing light beam to be incident to a photorefractive crystal, wherein the photorefractive crystal has holographic images recorded therein in a plurality of different angles respectively; a reflective mirror configured to reflect the reproducing light beam emitted from the light source to the photorefractive crystal; and a driving mechanism connected to the reflective mirror and configured to drive the reflective mirror to move on a plane elliptical arc, the plane elliptical arc is defined by using the light source and the photorefractive crystal as two mathematical focuses and using a predetermined constant, so that an incident angle of the reproducing light beam to be incident to the photorefractive crystal varies to form a plurality of reproducing light beams in different angles to be incident to the photorefractive crystal in sequence.

Embodiments of the present disclosure provide a holographic display device. The holographic display device includes a spatial light modulator and a light source unit. The light source unit is provided on the light entry side of the spatial light modulator and configured to providing read-out light to the spatial light modulator. The spatial light modulator includes at least one loading portion for receiving a write-in signal, which comprises a plurality of pixel units arranged in a matrix form, and the light exit surface of at least a part of which is a first cambered surface protruding in a direction away from the light source unit.

A laser beam (L50) is reflected by a light beam scanning device (60) and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a linear scatter body is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates the laser beam onto the hologram recording medium (45). At this time, by changing a bending mode of the laser beam with time, an irradiation position of the bent laser beam (L60) on the hologram recording medium (45) is changed with time. Diffracted light (L45) from the hologram recording medium (45) produces a reproduction image (35) of the linear scatter body on a light receiving surface (R) of the stage 210. When an object is placed on the light receiving surface (R), a line pattern is projected by hologram reproduction light, so that the projected image is captured and a three-dimensional shape of the object is measured.

An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.

An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.

Provided are holographic displays and operating methods of the holographic display. The holographic display includes a backlight portion configured to emit light for displaying an image; a deflector configured to control a direction at which the image is displayed; a lens portion configured to control a location where the image to be displayed is formed to match a location that satisfies a diffraction condition; and a panel portion configured to display a 3D image by combining the image to be displayed with an interference pattern generated with respect to an overlapped hologram.

Provided is a backlight unit having high optical efficiency and a holographic display device including the backlight unit. The backlight unit includes a light source unit configured to provide a light beam, a first beam expander configured to mix the light beam provided from the light source unit, expand the light beam in a first direction, and output the mixed and expanded light beam as white light, and a second beam expander configured to expand the white light output from the first beam expander in a second direction perpendicular to the first direction and output the expanded white light as surface light.

A holographic video display employs at least one light source adapted to produce at least one wavelength of monochromatic light, a video signal generator, at least one guided-wave acousto-optic modulator for diffracting light received from the light source according to signals received from the video signal generator, a vertical scanning subsystem, and an optical path between the acousto-optic modulator and the vertical scanning subsystem. The optical path may preferably include a Bravais lens system, at least one Fourier transform lens system, and at least one moving horizontal mirror.

[Problem to be Solved]

Conventional devices for reproduction of holograms for appreciative viewing do not have any functionality to gate access to special content by exploiting the characteristics of the hologram. Further, a system that allows users to easily perform judgment of authenticity has been much awaited as, with holograms, although a counterfeit prevention effect can be expected visually, counterfeit imitations of the holograms themselves are already in circulation.

[Means to Resolve the Problem]

It is made possible to read holographic barcodes with such portable information consoles as smartphones to perform judgment of authenticity. In this process, by controlling from the portable information console side the light sources illuminating the hologram, it is possible to add a strong authenticity judgment function without a major increase in cost and also without building any special infrastructure.