A method for replicating a holographic optical element and a holographic optical element replicated thereby are provided. The holographic optical element is larger than a master. The master has a holographic grating pattern generated on the master by interference of the reflected, diffracted or transmitted beam generated by irradiating the master having a specific diffraction grating pattern formed thereon with a laser beam.

The present invention relates to a method and apparatus for holographic recording based on holographic printing technology, and more specifically, to a method and apparatus for holographic recording, in which the hologram is recorded after the deviation in diffraction efficiency for each hogel is pre-compensated for by varying the intensity (luminance) of the object beam for each hogel during the hologram recording in response to a deviation in diffraction efficiency (reconstruction efficiency) for each hogel of a holographic recording surface that occurs when the hologram is reproduced. Accordingly, the reproduction imbalance of a near-eye display (NED) using a holographic optical element (HOE) is resolved by controlling the diffraction efficiency uniform on the entire holographic recording surface when the hologram is reproduced.

An optical data-storage system comprises a laser, an imaging optic, and associated computer logic. The laser is configured to emit a pulsed wavefront having uniform phase and polarization. The imaging optic is configured to modulate the phase and polarization of different portions of the wavefront by different amounts, and to diffract light from the different portions to a substrate with writeable optical properties. The logic is configured to receive data and to control modulation of the phase and polarization such that the light diffracted from the imaging optic writes the data to the substrate.

A hologram generation apparatus includes an LCOS, an LCOS display control unit configured to form a partial hologram generation display area and positioning hologram generation display areas on a display surface of the LCOS, an object light optical system configured to apply object light onto a recording medium and generate a partial hologram and positioning holograms, the object light being generated by the partial hologram generation display area and the positioning hologram generation display areas, and a position control unit configured to determine a position of an partial hologram to be generated next based on positions of the generated positioning holograms.

An optical head for a hologram optical apparatus and a method of operating the same are provided. The optical head for the hologram optical apparatus includes a reference light unit for guiding reference light, a signal light unit for guiding signal light, and a light source unit for providing 1 the reference light and the signal light to the reference light unit and the signal light unit, wherein the reference light unit and the signal light unit are stacked. The signal light unit includes: a plurality of optical waveguides stacked sequentially; composite hologram optical elements and lighting hologram optical elements disposed on the plurality of optical waveguides; an optical modulator for modulating light output from the plurality of the optical waveguides; and a lens for condensing light output from the optical modulator onto a recording layer.

A holographic printer using a vibration-free mechanical shutter is provided. A holographic printer, according to an embodiment of the present invention, comprises: a light source which emits light; a modulator which modulates the light emitted from the light source to generate a holographic fringe pattern in a hogel unit; a stage on which a holographic recording medium, on which a holographic fringe pattern generated by the modulator is to be recorded in a hogel unit, is placed; a driving part which moves a position of the stage in a hogel unit; and a shutter which periodically exposes, to the holographic recording medium, object light generated by the holographic fringe pattern generated by the modulator, wherein the shutter includes a rotating plate having a slit that exposes the object light by means of the holographic fringe pattern, and a motor rotating the rotating plate. Accordingly, by applying a mechanical shutter having a structure in which vibration does not occur to the holographic printer, it is possible to prevent degradation of hologram recording quality caused by vibration generated during opening/closing of the shutter.

Provided is a holographic printer using a mechanical shutter having adjustable exposure time and no vibration. The holographic printer according to an embodiment of the present invention comprises: a light source; a modulator for generating a holographic fringe pattern in hogel units; a stage on which a hologram recording medium is placed; a driving part for moving the position of the stage in hogel units; and a shutter for periodically exposing an object light due to the holographic fringe pattern generated by the modulator to the hologram recording medium. The shutter comprises: a rotation plate having formed therein an arc-shaped opening which exposes the object light due to the holographic fringe pattern; and a motor for rotating the rotation plate. Therefore, the exposure period and exposure time of the shutter can be variously adjusted by adjusting the rotational state of the rotation plates having the arc-shaped opening formed therein.

A hologram generation apparatus includes an LCOS, an LCOS display control unit configured to form a partial hologram generation display area and positioning hologram generation display areas on a display surface of the LCOS, an object light optical system configured to apply object light onto a recording medium and generate a partial hologram and positioning holograms, the object light being generated by the partial hologram generation display area and the positioning hologram generation display areas, and a position control unit configured to determine a position of an partial hologram to be generated next based on positions of the generated positioning holograms.

A holographic wavefront printing system and method are provided. A two-dimension digital blazed grating is loaded on a phase hologram, and the emergent direction of active region diffracted light is adjusted to prevent overlapping with the dead region diffracted light after being Fourier transformed by a lens, and a phase spatial light modulator is inclined by a preset angle to change the emergent direction of the diffracted light, such that the dead region zeroth-order and first-order diffracted light on a focusing surface are symmetrical with respect to a main optical axis of a first lens, the frequency spectrum center of active region zeroth-order diffracted light is then loaded to the original frequency spectrum center without information change. In this way, the adverse effects of the dead region diffracted light and active region high-order diffracted light of the phase spatial light modulator on holographic wavefront printing are eliminated.

Provided is a holographic recording method in which an interference fringe between a reference beam and a signal beam, modulated according to information regarding a plurality of hologram pixels, is recorded on a holographic recording medium, the holographic recording method including multiplexing-recording the interference fringe of the plurality of hologram pixels such that at least a part of the interference fringe recorded of neighboring hologram pixels of the plurality of hologram pixels is overlapped.