There is provided a holographic projector comprising a reflective liquid crystal display device. The reflective liquid crystal display device comprises a light-modulating layer between a first substrate and a second substrate substantially parallel to the first substrate. The light-modulating layer comprises planar-aligned nematic liquid crystals having positive dielectric anisotropy. The first substrate is substantially transparent and comprises a first alignment layer arranged to impart a first pre-tilt angle θ.sub.l on liquid crystals proximate the first substrate, wherein θ.sub.1>5°. The second substrate is substantially reflective and comprises a second alignment layer arranged to impart a second pre-tilt angle Θ.sub.2 on liquid crystals proximate the second substrate, wherein θ.sub.2>5°. The reflective liquid crystal display device further comprises a plurality of pixels defined on the light-modulating layer having a pixel repeat distance x, wherein x≤10 μm. The distance d between inside faces of the first substrate and second substrate satisfies 0.5 μm≤d≤3 μm, and the birefringence of the liquid crystal Δη≥0.20. The holographic projector further comprises a display driver arranged to drive the reflective liquid crystal display device to display a hologram by independently-driving each pixel at a respective modulation level selected from a plurality of modulation levels having a phase modulation value.

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.

A spatial light modulator (SLM) includes a first liquid crystal panel and a second liquid crystal panel that are oppositely configured, and a polarization adjustment part configured between the first liquid crystal panel and the second liquid crystal panel. An alignment direction of the first liquid crystal panel is parallel to an alignment direction of the second liquid crystal panel. The first liquid crystal panel is configured to perform a phase modulation on incident linear-polarized light. The polarization adjustment part is configured to rotate, by a preset angle, a polarization direction of linear-polarized light exited from the first liquid crystal panel. The second liquid crystal panel is configured to adjust a polarization state of linear-polarized light exited from the polarization adjustment part to adjust an amplitude of exited light.

A method of calculating a hologram having an amplitude and a phase component. The method comprises (i) receiving an input image comprising a plurality of data values representing amplitude. The method then comprises (ii) assigning a random phase value to each data value of the plurality of data values to form a complex data set. The method then comprises (iii) performing an inverse Fourier transform of the complex data set. The method then comprises (iv) constraining each complex data value (X1, X2) of the transformed complex data set to one of a plurality of allowable complex data values (GL1-GL8), each comprising an amplitude modulation value and a phase modulation value, to form a hologram, wherein, the phase modulation values (GL1-GL7) of the plurality of allowable complex data values substantially span at least 3π/2 and at least one of the allowable complex data values has an amplitude modulation value of substantially zero (GL8) and a phase modulation value of substantially zero.

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.

An illumination system is arranged to output a light beam for illuminating a scene. The system comprises a spatial light modulator arranged to receive incident light, and to output light comprising a first component and a second component. The first component comprises incident light that is output without modulation by the spatial light modulator. The second component comprises incident light that is spatially-modulated according to a hologram and output by the spatial light modulator. A control device is operable to control the proportion of light output by the spatial light modulator that corresponds to the second component.

A device for combining light beams which interact with adjacently arranged pixels of a light modulator, having a beam splitting component, a beam combining component, and a beam superposition component. The beam splitting component is configured such that incident light beams are split into a first subbeam and a second subbeam so that the first subbeam propagates toward a first pixel of the light modulator and the second subbeam propagates toward a second pixel of the light modulator. The beam combining component is configured and arranged so that the first subbeam and the second subbeam are combined after interaction with pixels of the light modulator. The beam splitting component and the beam combining component are configured and arranged in such a way that a sum of optical path lengths of the first subbeam and the second subbeam is respectively constant for different angles of incidence.

A compound metaoptic is presented. The compound metaoptic is comprised of at least two phase-discontinuous metasurfaces, which can convert an incident light beam to an aperture field with a desired magnitude, phase, and polarization profile. Each of the constitutive metasurfaces is designed to exhibit specific refractive properties, which vary along the metasurface. Furthermore, due to its transmission-based operation, the metaoptic can operate without lenses and be low profile: potentially having a thickness on the order of a few wavelengths or less. A systematic design procedure is also presented, which allows conversion between arbitrary complex-valued field distributions without reflection, absorption or active components. Such compound metaoptics may find applications where a specific complex field distribution is desired, including displaying holographic images and augmented or virtual reality systems.

Techniques for displaying an input image in improved perceived resolution are described. In one aspect, a circuit is designed to include a set of memory cells, a horizontal decoder and a vertical decoder. An input image is received at an interface to the memory, the input is expanded into two separate frames in the memory, where the size of each of the two frames is identical to that of the input image. Image data in at least one of the two frames are modulated in amplitude and/or in phase. The first and second frames are then read out or displayed alternatively at twice the refresh rate originally set for the input image to achieve the perceived resolution.

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.