A tunable liquid crystal (LC) device includes an LC layer between a pair of reflectors forming an optical cavity. The reflectors include conductive layers for applying an electrical signal to the LC layer. One of the conductive layers may include an array of conductive pixels for spatially selective control of the effective refractive index of the LC layer. The phase delay introduced by the LC layer may be greatly increased or magnified by placing the LC layer into the optical cavity. This enables a substantial reduction of the LC layer thickness, which in its turn enables very tight pitches of the LC pixels, with a reduced inter-pixel crosstalk caused by fringing electric fields, as well as faster switching times. A tight-pitch, fast LC device may be used as a configurable hologram or a spatial light modulator.

The invention provides a method, apparatus and system for separating blood and other types of cellular components, and can be combined with holographic optical trapping manipulation or other forms of optical tweezing. One of the exemplary methods includes providing a first flow having a plurality of blood components; providing a second flow; contacting the first flow with the second flow to provide a first separation region; and differentially sedimenting a first blood cellular component of the plurality of blood components into the second flow while concurrently maintaining a second blood cellular component of the plurality of blood components in the first flow. The second flow having the first blood cellular component is then differentially removed from the first flow having the second blood cellular component. Holographic optical traps may also be utilized in conjunction with the various flows to move selected components from one flow to another, as part of or in addition to a separation stage.

There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).

A printing device (106) includes a laser source and a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator). The printing device generates a laser control signal and a LCOS-SLM control signal. The laser source (110) generates a plurality of incident laser beams based on the laser control signal. The LCOS-SLM (112) receives the plurality of incident laser beams, modulates the plurality of incident laser beams based on the LCOS-SL M control signal to generate a plurality of holographic wavefronts (214,216) from the modulated plurality of incident laser beams. Each holographic wavefront forms at least one corresponding focal point. The printing device cures a surface layer or sub-surface layer (406) of a target material (206) at interference points of focal points of the plurality of holographic wavefronts. The cured surface layer of the target material forms a three-dimensional printed content.

A method for encoding complex-valued signals of a computer-generated hologram into a phase-modulating optical element for the reconstruction of a three-dimensional object, and to a computer program product for encoding complex-valued signals of a computer-generated hologram, and to a holographic display for the reconstruction of a three-dimensional object. The object is to reduce the effort on encoding a complex-valued spatial distribution by an iteration method on the basis of phase encoding, so that the computer-generated hologram resulting therefrom can be represented more rapidly and with the same or an improved reconstruction quality. In particular, the convergence during the iterative optimization is intended to be accelerated. This is achieved by a method in which degrees of freedom of the hologram plane as well as the reconstruction plane are used for optimizing the iteration method for rapid convergence and maximization of the diffraction efficiency in the signal range.

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 dual-modulation projection system (100) includes a light source (102), a phase modulator (104), an amplitude modulator (106), and a controller (110) having temporal lightfield simulation capabilities (114). The phase modulator (104) spatially modulates a lightfield from the light source (102) to generate an intermediate image on the amplitude modulator (106). The amplitude modulator (106) spatially modulates the intermediate image to form a final image. The controller (110) models the phase state of the phase modulator (104) during transitions between phase modulator frames and generates lightfield simulations of the intermediate image during the transition. The controller (110) utilizes the lightfield simulations to generate and provide sets of amplitude drive values to the amplitude modulator (106) at a faster rate than that at which the phase modulator (104) is capable of switching.

A projection system projects images onto a projection surface in, for example, a computer game head-mounted display (HMD). The light is projected through a spatial light modulator that contains a phase-only image of a Freeform Fourier Lens that is a combination of a Fresnel lens, an X-phase grating, a Y-phase grating, and a radial grating. The freeform lens is a condensing freeform lens that causes the gradual shrinking of portions of the laser-projected image, decreasing the perceived pixel pitch in at least one foveal area on the projection surface compared to a non-modulated laser image. The center positions of the Fresnel lens and radial grating can be changed in the X and Y axes, moving the condensed foveal areas in accordance with eye tracking of the user. In effect, the system projects a Foveated image that contains variable pixel pitch such that a user perceives a higher visual acuity in his gaze direction to the projected surface.

The present disclosure relates to a display device and a display method thereof. The display device includes: a plurality of sub-pixels each including a light emitting element and a liquid crystal spatial light modulator, wherein the liquid crystal spatial light modulator is located on a light emission side of the light emitting element, and a phase of light emitted by the light emitting element is modulatable after passing through the liquid crystal spatial light modulator; a first control circuit configured to control a light emission intensity and chromaticity of the light emitting element; and a second control circuit configured to control deflection of liquid crystal in the liquid crystal spatial light modulator so as to modulate the phase.

A holographic display system includes a light source that emits coherent light; a lateral displacement beam splitter that optically receives the coherent light and generates first reference light and second reference light; a first spatial light modulator (SLM) and a second SLM that optically receive the first reference light and the second reference light respectively, and construct first phase-only function (POF) light and second POF light respectively; a first beam splitter and a second beam splitter that optically receive the first POF light and the second POF light respectively, and generate first split light and second split light respectively; and a plurality of polarizers disposed between the first SLM and the first beam splitter, and between the second SLM and the second beam splitter, respectively.