A holographic display apparatus includes a light source disposed on a printed circuit board, a display panel diffracting light transferred from the light source, and an optical system disposed between the light source and the display panel. The optical system converts the light incident from the light source into a surface light source.

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 onto the hologram.

A holographic optical system is provided, including: a light source; a collimator, arranged to receive from the light source and having an output surface configured to provide collimated light, optical properties of the collimator generating aberrations in the collimated light; and an aberration-compensating holographic optical element having a planar diffractive surface arranged to receive collimated light from the output surface, the planar diffractive surface having optical properties such that output light from the planar diffractive surface is compensated for the aberrations generated by the collimator.

A method is provided. The method includes directing a first beam to a polarization sensitive recording medium. The method also includes directing a second beam to the polarization sensitive recording medium to interfere with the first beam to generate a polarization interference pattern, to which the polarization sensitive recording medium is exposed. One of the first beam and the second beam has a planar wavefront and the other has a non-planar wavefront. A first propagation direction of the first beam and a second propagation of the second beam are non-parallel.

A display device includes a light source part including a first light source and a second light source, a collimation lens that collimates light incident from the light source part, a wave guide that guides and diffracts the light incident from the collimation lens, a spatial light modulator that modulates the light passing through the wave guide so as to form a holographic pattern for reproducing a holographic image, a focusing optical system that focuses the holographic image on a space, and a light separating plate disposed between the light source part and the collimation lens, the light separating plate separating light of the first light source and light of the second light source from each other.

[Problem] Propagation of parallel light inside thin glass or plastic material had not been considered to be feasible because of difficulties in producing parallel light with large aspect ratio and in light-guiding it into thin material. For this reason, there had been a problem that holograms of edge-lit reproduction type were not being brought to practical use.

[Means for Solution] A compact, simple collimator optics has been successfully made by placing a holographic diffraction grating close to a diverging light source to propagate it at the critical angle inside the medium. By making an array of this diffraction grating it has become possible to propagate parallel light of any aspect ratio inside a thin plate. Hitherto unrealized image display devices and signal devices have become possible by using the holographic diffraction gratings as described in the foregoing, or other diffraction optical elements, to introduce light from a plurality of light sources, in combination with edge-lit reproduction type image holograms.

A holographic display apparatus includes a light source disposed on a printed circuit board, a display panel diffracting light transferred from the light source, and an optical system disposed between the light source and the display panel. The optical system converts the light incident from the light source into a surface light source.

A holographic sight comprises a unitary optical component carrier. The unitary optical component carrier may comprise a body with a first receptacle configured to receive a laser diode, a second receptacle configured to receive a mirror, a third receptacle configured to receive a collimating optic, a fourth receptacle configured to receive a grating, and a fifth receptacle configured to receive an image hologram. A laser diode may be received within opposing walls formed by the first receptacle. A mirror may be received in, and abut one or more surfaces of the second receptacle. A collimating optic may be received in, and abut one or more surfaces of the third receptacle. A grating may be received in, and abut one or more surfaces of the fourth receptacle. A hologram image may be received in, and abut one or more surfaces of the fifth receptacle.

A backlight module, a spatial light modulator, a holographic display device and a holographic display method therefor are disclosed. The backlight module includes: a light source; an optical conversion element arranged to face the light source and configured to convert a light beam emitted by the light source into coherent collimated light; and a light switch layer disposed at a side of the optical conversion element away from the light source. The optical conversion element includes a plurality of sub-optical conversion regions. The light switch layer includes a plurality of sub-light switches, the plurality of sub-light switches and the plurality of sub-optical conversion regions being disposed in one-to-one correspondence.

A hologram image acquiring apparatus includes a linear polarizer that filters incident light reflected by an object into a polarized component of a specific angle; a spherical lens that partially converts light that is incident through the linear polarizer to a spherical waveform; and a phase shifter that converts a part of the light incident through the spherical lens to a plane waveform having a respective phase per pixel unit.