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 holographic projection. The method comprises projecting at least one calibration image using a first colour holographic channel and a second colour holographic channel. Each calibration image comprises at least one light spot. The method comprises performing the following steps for each calibration image in order to determine a plurality of displacements vectors at a respective plurality of different locations on the replay plane. A first step comprises projecting the calibration image onto the replay plane using a first colour holographic channel by displaying a first hologram on a first spatial light modulator and illuminating the first spatial light modulator with light of the first colour. A second step comprises projecting the calibration image onto the replay using a second colour holographic channel by displaying a second hologram on a second spatial light modulator and illuminating the second spatial light modulator with light of the second colour. It may be said that the first and second hologram correspond to the calibration image. A third step comprises determining the displacement vector between the light spot formed by the first colour holographic channel and the light spot formed by the second colour holographic channel. A fourth step comprises pre-processing an image for projection using the second colour holographic channel in accordance with the plurality of determined displacement vectors.

Examples are disclosed that relate to holographic near-eye display systems. One example provides a near-eye display device, comprising a diverging light source, an image producing dynamic digital hologram panel configured to receive light from the diverging light source and form an image. The near-eye display device also includes and a combiner comprising a holographic optical element positioned to receive light from the dynamic digital hologram panel and to redirect the light toward an eyebox, the holographic optical element being positioned between the eyebox and a view of an external environment to combine a view of the image formed by the dynamic digital hologram panel and the view of the external environment.

A laser beam (L50) generated by a laser light source (50) is reflected by a light beam scanning device (60), and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates it onto the hologram recording medium (45). At this time, scanning is carried out by changing the bending mode of the laser beam with time so that the irradiation position of the bent laser beam (L60) on the hologram recording medium (45) changes with time. Regardless of the beam irradiation position, diffracted light (L45) from the hologram recording medium (45) reproduces the same reproduction image (35) of the scatter plate at the same position. An illumination spot in which speckles are reduced is formed on the light receiving surface (R) of an illuminating object (70) by the reproduction image (35) of the hologram.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

A backlight module, a spatial light modulator, a holographic display device and a holographic display method therefor are disclosed. The backlight module includes: a light source; an optical conversion element arranged to face the light source and configured to convert a light beam emitted by the light source into coherent collimated light; and a light switch layer disposed at a side of the optical conversion element away from the light source. The optical conversion element includes a plurality of sub-optical conversion regions. The light switch layer includes a plurality of sub-light switches, the plurality of sub-light switches and the plurality of sub-optical conversion regions being disposed in one-to-one correspondence.

A beam deflector and a holographic three-dimensional image display apparatus employing the same are provided. The beam deflector deflects light through two stages by a first beam deflector that deflects the light in a first moving direction making an angle with a horizontal direction and a vertical direction, such that the deflected light is oriented to a first location, and a second beam deflector that deflects the light incident from the first beam deflector such that the light is deflected in a second moving direction making an angle with the horizontal direction and the vertical direction at the first location and is oriented to a second location.

An optical device including a hologram recording medium that can reproduce an image of a reference member and an irradiation unit that emits a coherent light beam to the optical device. The irradiation unit includes a light source for emitting a coherent light beam and a scanning device capable of adjusting a reflection angle of the coherent light beam emitted from the light source and that makes a reflected coherent light beam scan the hologram recording medium. The light source has light sources for emitting coherent light beams having different wavelength ranges. The hologram recording medium has a plurality of recording areas to be scanned with a plurality of coherent light beams reflected by the scanning device, respectively. Each of the plurality of recording areas has an interference fringe that diffracts a coherent light beam of the corresponding wavelength range.

There is provided a lighting system for a vehicle. The lighting system comprises a holographic projector and a light distribution system. The holographic projector comprises a hologram engine and a spatial light modulator. The hologram engine is arranged to output holograms. The spatial light modulator is arranged to display each hologram and spatially-modulate light in accordance with each hologram. The spatially-modulated light forms a holographic reconstruction, corresponding to each hologram, on a replay plane. The light distribution system comprises a plurality of optical fibres. Each optical fibre comprises an input optically-coupled to respective sub-area of the replay plane and an output optically coupled with an illumination sub-system of the vehicle.

A holographic display is comprised of space-multiplexed elemental modulators, each of which consists of a surface acoustic wave transducer atop an anisotropic waveguide. Each line of the overall display consists of a single anisotropic waveguide across the display's length with multiple surface acoustic wave transducers spaced along the waveguide length, although for larger displays, the waveguide may be divided into segments, each provided with separate illumination. Light that is undiffracted by a specific transducer is available for diffraction by subsequent transducers. Per transducer, guided-mode light is mode-converted to leaky-mode light, which propagates into the substrate away from the viewer before encountering a volume reflection grating and being reflected and steered towards the viewer. The display is transparent and all reflection volume gratings operate in the Bragg regime, thereby creating no dispersion of ambient light.