There is provided a holographic projector comprising a spatial light modulator, a light source and an assembly. The spatial light modulator is arranged to display a hologram. The light source is arranged to illuminate at least one region of the spatial light modulator with an input beam such that the input beam is spatially modulated by the spatial light modulator in accordance with the hologram to form a holographic reconstruction. The assembly is arranged to move at least one of the input beam and the spatial light modulator relative to the other.

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 is combined with 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 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.

There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) minor enables rear illumination of a reflection hologram.

Embodiments described herein relate to a large area lens-free imaging device. One example is a lens-free device for imaging one or more objects. The lens-free device includes a light source positioned for illuminating at least one object. The lens-free device also includes a detector positioned for recording interference patterns of the illuminated at least one object. The light source includes a plurality of light emitters that are positioned and configured to create a controlled light wavefront for performing lens-free imaging.

A system for measuring vibrations of a surface (VSURF) of a mechanical part (M), comprising a source (SOURCE) of radiation (L), a first separator element (ELI) configured to define a first incident ray (LB1) and a reference ray (RLB), a shaping module (DOEM) producing a second incident ray (LB2) from said first incident ray (LB1), and an optical element (OE) capable of an interferential addition of the reference ray (RLB) and a ray produced by a reflection of said second incident ray (LB2) on said surface (VSURF), the shaping module (DOEM) comprising one or more diffracting optical elements (DOE1, . . . , DOEn), each comprising at least one diffraction structure (FSTRUCT) diffracting all or part of the first incident ray (LB1) so as to illuminate a chosen surface of the mechanical part.

A light irradiation device includes a Gaussian beam output unit for outputting light having a light intensity distribution that conforms to a Gaussian distribution, a spatial light modulator for receiving the light and modulating the light by presenting a CGH, an optical system for converging the modulated light, and an amplitude mask arranged on at least one of an optical axis between the Gaussian beam output unit and the spatial light modulator and an optical axis between the spatial light modulator and the optical system. The amplitude mask has a circular-shaped first region centered on the optical axis and an annular-shaped second region that surrounds the first region. Transmittance in the second region continuously decreases as a distance from the optical axis increases.

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.

Example embodiments provide systems and methods for correcting non-uniformities of a light beam generated by a multi-emitter light source. In some embodiments a phase modulator displays patch lenses to correct for the non-uniformities. In some embodiments each region of the phase modulator is illuminated by a beam generated by one emitter of the multi-emitter light source. Such region of the phase modulator may display a patch lens for correcting non-uniformities in the corresponding beam which illuminates the region.

A method of manufacturing a holographic element used in a projection device is provided. The projection device has a light source configured to emit light conforming to a non-uniform light intensity distribution function. The method includes: multiplying the non-uniform light intensity distribution function by a diffraction intensity and angle function of a grating to obtain a product function; determining whether the product function is substantially equal to 1 in a predetermined range of angle or wavelength; if the the determination result is yes, determining a pair of incident angles respectively of a reference beam and a signal beam according to the diffraction intensity and angle function; and recording a holographic material with the reference beam and the signal beam respectively at the pair of incident angles, so as to manufacture a holographic element with the grating therein.

An apparatus for suppressing electron/hole recombination includes a photonic device that generates electron/hole pairs responsive to a light beam interacting with the photonic device. An orbital angular momentum (OAM) generation device is located to impart an orbital angular momentum to a light beam before the light beam interacts with the photonic device. The electron/hole pair recombination generated from an OAM imparted light beam is less than electron/hole pair recombination of a non-OAM imparted light beam.