A three-dimensional light modulator, of which the pixels are combined to form modulation elements. Each modulation element can be coded with a preset discrete value such that three-dimensionally arranged object points can be holographically reconstructed. The light modulator is characterized in that assigned to the pixels of the modulator are beam splitters or beam combiners which, for each modulation element, combine the light wave parts modulated by the pixels by means of refraction or diffraction on the output side to form a common light beam which exits the modulation element in a set propagation direction.

Architecture and designs of modulating both amplitude and phase at the same time in spatial light modulation are described. According to one aspect of the present invention, nano-imprinting lithograph (NIL) and E-beam are used to create micro structures (transparent) as alignment cells. A first group of the alignment cells are oriented in a first direction and a second group of the alignment cells are oriented in a second direction, light going through the first group of the alignment cells is modulated in amplitude thereof and the light going through the second group of the alignment cells is modulated in phase thereof, all via the liquid crystals and at the same time.

An illumination device for illuminating a spatial light modulator device. Sub-holograms are used for encoding a hologram into the spatial light modulator device. The Illumination device includes at least one light source for emitting light for illuminating the spatial light modulator device and a beam shaping unit. The beam shaping unit provides a flat-top plateau-type distribution of an absolute value of a complex degree of mutual coherence of the light in a plane of the spatial light modulator device to be illuminated. The flat-top plateau-type distribution of the absolute value of the complex degree of mutual coherence has a shape that is at least similar to a shape of the largest sub-hologram used for encoding of object points into the spatial light modulator device.

Techniques for holographic display by modulating optical images in amplitude and phase via a layer of liquid crystals are described. According to one aspect of the techniques, a voltage being applied or coupled across the layer of liquid crystals is controlled by gradually increasing the voltage from a low level to a high level to perform the AM in a first range and the PM in second range, where the characteristics of the liquid crystals is significant, for example, by increasing the thickness or optical birefringence of the layer of liquid crystals.

Various embodiments set forth optical patterning systems. Each pixel of the optical patterning systems includes an amplitude-modulating cell that is in line with a phase-modulating cell. The amplitude-modulating cell includes a liquid crystal and a drive method for modulating at least the amplitude of a wavefront of light that passes through the amplitude-modulating cell. The phase-modulating cell includes a liquid crystal and a drive method for modulating at least the phase of a wavefront of light that passes through the phase-modulating cell. In some embodiments, the amplitude-modulating cell shares a common ground with the phase-modulating cell. The amplitude-modulating cell and the phase-modulating cell can be used to independently control the amplitude change and phase delay imparted by the pixel, enabling complex wavefront modulation.

Provided is a complex light modulator including a phase modulator, and an amplitude modulator, wherein the phase modulator and the amplitude modulator are configured to generate a first complex pixel having first complex light modulation characteristics and a second complex pixel having second complex light modulation characteristics, wherein the first complex pixel includes first sub-complex pixels that are provided in a 3×3 format and are configured to implement the first complex light modulation characteristics, wherein the second complex pixel includes second sub-complex pixels that are provided in a 3×3 format and are configured to implement the second complex light modulation characteristics, and wherein the first complex pixel and the second complex pixel respectively include a first overlapping pixel that is included in the first sub-complex pixels and the second sub-complex pixels.

An illumination device for illuminating a spatial light modulator device. Sub-holograms are used for encoding a hologram into the spatial light modulator device. The Illumination device includes at least one light source for emitting light for illuminating the spatial light modulator device and a beam shaping unit. The beam shaping unit provides a flat-top plateau-type distribution of an absolute value of a complex degree of mutual coherence of the light in a plane of the spatial light modulator device to be illuminated. The flat-top plateau-type distribution of the absolute value of the complex degree of mutual coherence has a shape that is at least similar to a shape of the largest sub-hologram used for encoding of object points into the spatial light modulator device.

Techniques for modulating both amplitude and phase via a layer of liquid crystals are described. According to one aspect of the techniques, a voltage being applied or coupled across the layer of liquid crystals is controlled by gradually increasing the voltage from a low level to a high level to perform the AM in a first range and the PM in second range, where the characteristics of the liquid crystals is significant, for example, by increasing the thickness or optical birefringence of the layer of liquid crystals.

The present invention provides a holographic imaging device and a holographic imaging method that have improved performance in which the influence of a refractive index of a cube-type beam coupler constituting an optical system is considered. The holographic imaging device 1 comprises the beam coupler 3 consisting of the cube-type beam splitter arranged between the object 4 and the image sensor 5 and the calculation reference light hologram generation unit 14 for generating an inline reference light hologram j.sub.L representing a light wave on the hologram plane 50 by performing a light wave propagation calculation including propagation inside the beam coupler 3, on a spherical wave emitted from the condensing point P2 of the inline spherical wave reference light L. The inline reference light hologram j.sub.L is a computer-generated hologram and used for generating an object light hologram g by removing component of the reference light L from a complex-amplitude inline hologram J.sub.OL representing the object light O and the inline spherical wave reference light L on the hologram plane 50.

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.