A printing device (106) includes a laser source and a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator). The printing device generates a laser control signal and a LCOS-SLM control signal. The laser source (110) generates a plurality of incident laser beams based on the laser control signal. The LCOS-SLM (112) receives the plurality of incident laser beams, modulates the plurality of incident laser beams based on the LCOS-SLM control signal to generate a plurality of holographic wavefronts (214,216) from the modulated plurality of incident laser beams. Each holographic wavefront forms at least one corresponding focal point. The printing device cures a surface layer or sub-surface layer (406) of a target material (206) at interference points of focal points of the plurality of holographic wavefronts. The cured surface layer of the target material forms a three-dimensional printed content.

An optical device including a hologram recording medium that can reproduce an image of a reference member and an irradiation unit that emits a coherent light beam to the optical device. The irradiation unit includes a light source for emitting a coherent light beam and a scanning device capable of adjusting a reflection angle of the coherent light beam emitted from the light source and that makes a reflected coherent light beam scan the hologram recording medium. The light source has light sources for emitting coherent light beams having different wavelength ranges. The hologram recording medium has a plurality of recording areas to be scanned with a plurality of coherent light beams reflected by the scanning device, respectively. Each of the plurality of recording areas has an interference fringe that diffracts a coherent light beam of the corresponding wavelength range.

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.

The invention relates to a display device, in particular a head-mounted display or hocular, having a spatial light modulator and a controllable light-deflecting device for generating a multiple image of the spatial light modulator, which consists of segments, the multiple image being produced at least with a predefinable number of segments which determines the size of a visible area within which a 3D-scene holographically encoded in the spatial light modulator can be reconstructed for observation by an eye of an observer.

In a method for forming a holographic image, light is provided to a flat-panel holographic video display that includes waveguide elements that each have a light-guiding substrate and an array of transducers configured to produce a diffraction grating comprising surface acoustic waves. The grating causes the waveguide to outcouple light, focusing it to, or producing wavefront curvatures consistent with it having emanated from, one or more points, in order to form a holographic image. The transducer array may include a large number of densely packed, vertically-adjacent transducers for each hogel for full parallax or may include a small number of vertically-adjacent transducers and a cylindrical optical element for each hogel. The display may be edge-illuminated by a collinear multicolor source. The substrate exit face may have nanopatterned areas alternated with flat areas in order to create regions of optimal internal reflection next to regions of low reflection.

A backlight device having a light guide, a first holographic optical element and a second holographic element are provided. The light guide plate guides light emitted by a light source towards the first holographic optical element. The first holographic optical element, which has a multi-layered structure, is provided on a first side of the light guide plate and reflects the light according to the wavelength ranges based on the characteristics of the multi-layered structure. The second holographic optical element, which concentrates light reflected by the first holographic optical element onto at least two points is provided on a second side of the light guide plate perpendicular to the first side.

A backlight device having a light guide, a first holographic optical element and a second holographic element are provided. The light guide plate guides light emitted by a light source towards the first holographic optical element. The first holographic optical element, which has a multi-layered structure, is provided on a first side of the light guide plate and reflects the light according to the wavelength ranges based on the characteristics of the multi-layered structure. The second holographic optical element, which concentrates light reflected by the first holographic optical element onto at least two points is provided on a second side of the light guide plate perpendicular to the first side.

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.

An illumination apparatus using a coherent light source, including a light beam scanning device that irradiates a light beam onto a hologram recording medium, and scans the light beam so that an irradiation position of the light beam on the hologram recording medium changes with time. The light beam scanning device scans the light beam so that an irradiation direction of the light beam with respect to the hologram recording medium is along the particular optical path, the light beam scanning device having a function of bending the light beam at a fixed scanning origin so that the light beam swings around the fixed scanning origin on a plane including the fixed scanning origin, and scans the light beam in a one-dimensional direction on the hologram recording medium. Illumination light obtained from the hologram recording medium is irradiated onto a light receiving surface.

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.