There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

A method for observing a sample is provided, including illuminating the sample with a light source and forming a plurality of images, by an imager, the images representing the light transmitted by the sample in different spectral bands. From each image, a complex amplitude representative of the light wave transmitted by the sample is determined in a determined spectral band. The method further includes backpropagation of each complex amplitude in a plane passing through the sample, determining a weighting function from the back-propagated complex amplitudes, propagating the weighting function in a plane along which the matrix photodetector extends, updating each complex amplitude, in the plane of the sample, according to the weighting function propagated.

When coating a document surface (3) having relief-like information (1) carrying personal data, for example, with a monomer-containing liquid UV adhesive (4) across the entire surface and then laminating thereon a volume hologram (2), the varying adhesive thicknesses between the volume hologram and the document surface resulting from the relief cause differentiated swelling and thereby a differentiated color shift of the hologram. After the desired color shift is achieved, the UV adhesive (4) is completely cured. In this way, individual holographic information is obtained, which is located exactly above the relief-like information of the document. With this method, holographic overlays comprising personal data and a passport picture can be produced, and it is possible to link defined optical document information to the hologram in an accurately positioned manner, so that information is visible both non-diffractively and, from a different viewing angle, holographically in a different color.

An apparatus for, and method of, image reconstruction. The method includes first breaking a holographic image into a plurality of interlaced sample sets corresponding to color separation images; and independently sampling, filtering, and reconstructing all sets. The resulting demodulated images contain no fringes. Notably, range-clipped tonal rendering curves are used to choose pixel regions of the demodulated images that will replace saturated regions. The image is reconstructed by integrating all un-saturated images into one.

A device for producing a subwavelength hologram. The device comprises a metasurface layer attached to a substrate. The metasurface layer includes an array of plasmonic antennas that simultaneously encode both wavelength and phase information of light directed through the array to produce a hologram. The wavelength is determined by the size of the antennas, and the phase is determined by the orientation of the antennas.

Various holographic films for recording multicolor volume holograms, especially full color volume reflection holograms, and to manufacturing techniques for such film, and to corresponding methods of recording multicolor and full-color volume, in particular volume reflection holograms. We describe a holographic film for recording a multicolor volume hologram, the film including: a carrier; a first photosensitive recording layer sensitive to one or both of red and green laser light; and a second photosensitive recording layer sensitive to blue laser light. Both the first and second photosensitive recording layers include silver halide and have a grain size of less than 30 nm, and at least one of the photosensitive recording layers has a thickness of greater than 3 ?m and less than 5 ?m.

A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises Fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises Fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

Described herein is a new holographic polymer dispersed liquid crystal (HPDLC) medium with broadband reflective properties, and a new technique for fabrication of broadband HPDLC mediums. The new technique involves dynamic variation of the holography setup during HPDLC formation, enabling the broadening of the HPDLC medium's wavelength response. Dynamic variation of the holography setup may include the rotation and/or translation of one or more motorized stages, allowing for time and spatial, or angular, multiplexing through variation of the incident angles of one or more laser beams on a pre-polymer mixture during manufacture. An HPDLC medium manufactured using these techniques exhibits improved optical response by reflecting a broadband spectrum of wavelengths. A new broadband holographic polymer dispersed liquid crystal thin film polymeric mirror stack with electrically-switchable beam steering capability is disclosed.