Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

A backlight unit for a binocular-holographic display device and a holographic display device including the same are provided. The backlight unit includes a light source unit which outputs light, a first beam expansion unit which expands, in a first direction, the light output from the light source unit, a second beam expansion unit which expands, in a second direction perpendicular to the first direction, the light output from the first beam expansion unit, and a beam deflection unit which diffracts light incident on the first beam expansion unit. The holographic display device includes the backlight unit, a field lens, and a spatial light modulator.

A near-eye display includes a light source, an optical system, and a phase map. The light source emits illumination light. The optical system is configured to receive the illumination light from the light source and output the illumination light as an in-phase wavefront. The phase map is configured to adjust a phase of the in-phase wavefront to form an image in response to being illuminated by the in-phase wavefront. The phase map is pre-recorded with a phase pattern that generates the image.

A display device includes a light source, a waveguide element, a liquid crystal coupler, a first holographic optical element and a second holographic optical element. The light source is configured to emit light. The waveguide element is located above the light source. The liquid crystal coupler is located between the waveguide element and the light source. The first holographic optical element is located on a top surface of the waveguide element, in which the liquid crystal coupler is configured to change an incident angle that the light emits to the first holographic optical element. The second holographic optical element is located on the top surface of the waveguide element, and there is a first distance in a horizontal direction between the first holographic optical element and the second holographic optical element, in which the second holographic optical element is configured to diffract the light to the waveguide element below.

A light-emitting device including at least a metal layer able to be heated and to propagate surface waves consecutive to the heating of the metal layer, with the metal layer being structured such that it comprises several diffraction patterns able to carry out a diffraction of the surface waves to free-space propagation modes, wherein a synthetic hologram is encoded such that a phase image of a pixel of the hologram is encoded by an offset in the position of one of the diffraction patterns, and a heater of the metal layer.

Light-emitting devices for motor vehicles are provided, which comprise a reflection hologram. A light-guiding body is provided to direct light from a light source arrangement (4) onto the hologram.

A holographic see-through optical device, a stereoscopic imaging system including the same, and a multimedia head mounted system are provided. The holographic see-through optical device includes a micro display; a relay optical system, which relays an image generated by the micro display; at least one waveguide comprising at least two portions having different thicknesses or different refractive indexes; at least one first holographic optical element, which is arranged at one of the two portions; and at least one second holographic optical element, which is arranged at the other one of the two portions.

An interactive 3D display apparatus and method are provided. The interactive 3D display apparatus includes a hand sensing module configured to acquire a hand image by detecting a hand of a user and a user interaction module configured to generate a virtual object adjustment parameter by analyzing user-intended information about the hand based on the hand image acquired by the hand sensing module and comparing an analysis result with predefined user scenarios, an image rendering module configured to set a scene according to the generated virtual object adjustment parameter, generate image data by rendering the set scene, and convert the generated image data into display data, and a 3D display configured to display a 3D image including a virtual object in which a change intended by the user has been reflected according to the display data.

The present invention provides a light-guiding plate which is applicable to incident rays over a wide ray angular range and wide wavelength rage, and is able to suppress a decrease in optical efficiency. A light-guiding plate 200 having a light diffracting portion 1200 for diffracting incident light by a multiple-recorded hologram is configured such that, in the light diffracting portion, when light 1210 of a single wavelength having a certain angular range is incident, at least two or more outgoing rays 1220 are discretely emitted with a first angular space θs, and the emitted rays each have a second angular range θa, and the first angular space θs is equal to or larger than the second angular range θa.

An electronic device may include an optical system that redirects light from a display module towards an eye box along an optical path. The optical path may include a holographic coupler and a resolution-enhancing holographic element. The holographic element may include a first set of holograms and the coupler may include a second set of holograms. The first set of holograms may be characterized by a first set of selectivity curves having first primary lobes. The second set of holograms may be characterized by a second set of selectivity curves having second primary lobes that overlap the first primary lobes. This may configure the holographic element to narrow the second selectivity curves by diffracting some of the light out of the optical path, thereby optimizing the resolution of images in the light provided to the eye box.