A freeform holographic imaging apparatus includes an imaging table for supporting a substrate, an imaging beam positioned adjacent to the imaging table; and a controller operatively connected to the imaging beam and configured to control a position of the imaging beam with respect to the imaging table. The controller is configured to control the imaging beam to image first and second holographic optical elements on the substrate, wherein each of the first and second holographic optical elements are a single pixel. The first holographic optical element is imaged according to a first parameter set and the second holographic optical element is imaged according to a second parameter set.

Lighting information comprising at least the reflectance data of a plurality of regions of an object surface is generated and printed out as a series of relightable holograms. Each of the printed holograms comprises the reflectance data of a corresponding region of the object. A model of the object is generated such that the model also comprises a plurality of portions corresponding to the regions of the object surface. The series of holograms are each affixed to a portion of the model such that a particular hologram of the series which encodes the reflectance data of a particular region of the object is affixed to the corresponding portion of the model. In an embodiment, the model of the object is generated from a metal. The series of holograms is engraved directly onto the metallic model such that a particular hologram of the series which encodes the reflectance data of a particular region of the object is engraved onto the corresponding portion of the metallic model.

Lighting information comprising at least the reflectance data of a plurality of regions of an object surface is generated and printed out as a series of relightable holograms. Each of the printed holograms comprises the reflectance data of a corresponding region of the object. A model of the object is generated such that the model also comprises a plurality of portions corresponding to the regions of the object surface. The series of holograms are each affixed to a portion of the model such that a particular hologram of the series which encodes the reflectance data of a particular region of the object is affixed to the corresponding portion of the model. In an embodiment, the model of the object is generated from a metal. The series of holograms is engraved directly onto the metallic model such that a particular hologram of the series which encodes the reflectance data of a particular region of the object is engraved onto the corresponding portion of the metallic model.

Holograms are generated using a rotatable transparent cylinder and a coherent light source placed inside or outside of such cylinder to record a hologram in a photosensitive film having a reflective film on one side. Recording is done in continuous mode while cylinder is rotating and photosensitive film is translating underneath in contact with cylinder due to friction forces provided by a layer of sticky polymer.

Provided is a hologram printing method and apparatus using a hologram medium light efficiency map. A hologram printing method according to an embodiment emits a laser to a hologram medium, acquires an image by photographing light diffracted from the hologram medium, generates a light efficiency map of the hologram medium from the acquired image, and records hogels on the hologram medium by referring to the generated light efficiency maps of the hologram medium. Accordingly, light efficiency is measured on each hogel area, and hologram printing is performed by adjusting an intensity of a laser of each wavelength according to a hogel, so that uniformity of luminance and color of a hologram printing result can be enhanced.

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.

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.