Provided are a method and an apparatus for printing a hologram by using a mask. The hologram printing method according to an embodiment generates a hologram fringe pattern, splits the hologram fringe pattern on a hogel basis, generates the split hogels, masks a part of the generated hogel, and prints the masked hogel on a hologram medium. Accordingly, an empty space which occurs between hogels when a hologram is printed is prevented from being generated by using a mask, so that a fill factor can be effectively enhanced, and eventually, image quality of a hologram can be enhanced.

A display system for a vehicle includes a display unit mounted to the vehicle and is selectively operable in a first mode as a holographic display and in a second mode as a mirror. Holographic images may include rear view images obtained from a camera or computer generated graphics. Holographic images are displayed at a virtual image plane behind the display to reduce the operator's eyes accommodation.

A method for producing a volume hologram with at least one first area in a first color and at least one second area in a second color includes, providing a volume hologram layer made of a photopolymer; arranging a master with a surface structure on the volume hologram layer; exposing the master using coherent light, wherein light which is incident on at least one first partial area of the surface of the master is diffracted or reflected in the direction of the at least one first area of the volume hologram layer and light which is incident on at least one second partial area of the surface of the master is diffracted or reflected in the direction of the at least one second area of the volume hologram, and wherein the light diffracted or reflected by the first and second partial areas differs in at least one optical property.

Provided is a technology for implementing an AR optical waveguide display capable of showing a hologram image by means of a small and simple system configuration by using an HOE. A holographic display according to an embodiment of the present invention comprises: a light source module for emitting a beam; an optical waveguide through which the emitted beam is incident and propagated; a plurality of holographic optical elements (HOES) for propagating the beam incident to the optical waveguide inside the optical waveguide while totally reflecting the beam; and a modulator for reproducing a holographic image through the progressing beam and propagating the beam to the inside of the optical waveguide while totally reflecting the beam. Accordingly, it is possible to implement, as a small and simple system, an optical waveguide display showing an AR hologram by using an optical waveguide and an HOE.

A holographic display apparatus capable of providing an expanded viewing window and a display method are provided. The holographic display apparatus includes an image processor configured to provide computer generated hologram (CGH) data to a spatial light modulator, wherein the image processor is further configured to generate a hologram data array comprising information of the holographic image to be reproduced at the first resolution or a resolution less than the first resolution, perform an off-axis phase computation on the hologram data array at the second resolution, and then, generate the CHG data at the first resolution.

An all-optical hologram reconstruction system and method is disclosed that can instantly retrieve the image of an unknown object from its in-line hologram and eliminate twin-image artifacts without using a digital processor or a computer. Multiple transmissive diffractive layers are trained using deep learning so that the diffracted light from an arbitrary input hologram is processed all-optically to reconstruct the image of an unknown object at the speed of light propagation and without the need for any external power. This passive diffractive optical network, which successfully generalizes to reconstruct in-line holograms of unknown, new objects and exhibits improved diffraction efficiency as well as extended depth-of-field at the hologram recording distance. The system and method can find numerous applications in coherent imaging and holographic display-related applications owing to its major advantages in terms of image reconstruction speed and computer-free operation.

Methods, devices and systems for improved fabrication and measurement of holographic elements are described. One example method includes directing a reference and an object beam toward a holographic material for formation of a diffraction grating in the holographic material, and blocking one of the reference or the object beams to prevent the beam from reaching the holographic material for at least a portion of time during which the diffraction grating is being formed. During the blockage of the beam, a power level of a diffracted beam associated with the reference or the object beam that is not being blocked is measured. Based on the measured power level, it is then determined whether a particular diffraction grating efficiency is reached. The described techniques enable real-time measurement of diffraction grating efficiency as the grating is being formed and enable improved fabrication of holographic elements hat must meet precise diffraction grating efficiency requirements.

An apparatus and method to produce a hologram of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the object from the captured image.

A holographic display and a method, performed by the holographic display, of forming a holographic image are disclosed. The holographic display includes an electrically addressable spatial light modulator (EASLM); a diffractive optical element (DOE) mask array arranged on the EASLM; and a controller configured to operate the holographic display to form a hologram image, wherein the controller is further configured to address the EASLM to backlight the DOE mask array required to form a set of hologram image voxels by turning on a corresponding EASLM pixel.

A device and a method for manufacturing holographic optical elements. The device includes at least two partial light beams and one interference light beam, one deformable mirror in each case per partial light beam, a control unit, which is configured to actuate the deformable mirrors to adapt a wavefront of the partial light beam, and a holographic film. The deformable mirrors are situated so as to each reflect precisely one partial light beam and to direct the reflected partial light beam on the holographic film, and the interference light beam being directed on the holographic film to interfere with the reflected partial light beams so as to simultaneously generate at least two holographic optical elements.