A holographic display system comprises a light source configured to emit at least partially coherent light; a modulator arranged to be illuminated by the at least partially coherent light and to generate a light field which is a quantised representation of a target light field, H; and a spatial filter delimiting an aperture in a Fourier plane. A Fourier transform of the target light field, F(H), substantially does not overlap (i) a Fourier transform of a complex conjugate of the target light field, F(H*), (ii) a Fourier transform of the target light field multiplied by the complex conjugate of the target light field, F(HH*), (iii) a Fourier transform of a square of the target light field, F(H.sup.2), and (iv) a Fourier transform of a square of the complex conjugate of the light field F(H*.sup.2). The aperture substantially corresponds to F(H) in the Fourier plane.

In the present invention, by providing an apparatus for displaying a hologram including: a beam source configured to output a plurality of beams, a spatial light modulator configured to include a plurality of SLM (spatial light modulator) regions, display a hologram, and diffract the plurality of beams; a plurality of front lenses each corresponding to the plurality of SLM regions, and configured to refract the plurality of beams diffracted from each of the plurality of SLM regions; a plurality of filters each corresponding to the plurality of SLM regions, and configured to filter a part of the plurality of refracted beams; and a plurality of back lenses each corresponding to the plurality of SLM regions, and configured to display an interference image corresponding to the hologram using the filtered part beam, the beam path of the hologram displaying apparatus can be drastically reduced, and an entire size of the hologram displaying apparatus can be reduced, so that it is possible to down-size the digital hologram display system.

According to the present invention, by providing a hologram displaying apparatus including a light source configured to output a plurality of lights of different wavelengths in a first direction, a generator configured to generate a plurality of color holograms of different wavelengths using the plurality of light, and output the plurality of color holograms in the first direction, a filter configured to filter an effective hologram which is an element of an effective band of the plurality of color holograms in the first direction, and a display configured to transmit the effective hologram in the first direction and display the effective hologram in space in the first direction, it is possible to effectively filter an effective band of a certain diffraction order of each color hologram forming a composing hologram.

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.

Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present application, a fast and simple way to correct for defocus aberration is described. A variety of applications for the method are presented.

A holographic projector includes a display device arranged to form a holographic wavefront by spatially modulating light in accordance with a hologram of a picture. The holographic projector includes a magnification system including a first and second lens. The first lens is arranged form a holographic reconstruction of the picture by focusing the holographic wavefront towards a front focal plane of the first lens. The holographic reconstruction of the picture includes a plurality of pixels. The holographic projector includes a kinoform disposed between the first and second lens and arranged to apply a phase-delay to each pixel of the holographic reconstruction. The holographic projector includes a movement assembly arranged to move the kinoform such that a plurality of different phase-delays are applied to each pixel. The kinoform includes an array of zones and is arranged such that the width of each zone is substantially equal to the distance between adjacent pixels.

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 holographic head-up display device includes: a light source portion that emits coherent light; an optical modulation portion that modulates the coherent light; a relay optical system that focuses the modulated light; a filter mirror that includes a reflection area disposed at a focal position of the relay optical system and reflecting light incident through the relay optical system and an absorption area disposed at the periphery of the reflection area and absorbing light incident through the relay optical system; and a transflective mirror that partially transmits and partially reflects light reflected by the filter mirror.

A method for directing non-modulated light from a Spatial Light Modulator (SLM) and allowing through modulated light for producing an interference based holographic image, the method including illuminating the SLM with coherent light, thereby producing a mix of light modulated by the SLM and light not modulated by the SLM, and projecting the mix of the modulated light and the not modulated light along an optical axis onto a volume grating, wherein the volume grating directs the not modulated light away from the holographic image and allows through modulated light for producing the holographic image. Related apparatus and methods are also described.

An optical detection system uses high-resolution holographic filters for target detection within a very-large field of view image acquired with a reflector. The holographic filter acts as an optical computer, mixing phase and amplitude information of known targets with light from the scene, automatically enhancing portions of the image that match threat objects or other object of interest. A lens forming a Fourier transform of the entire scene is used, and within that transform, the holographic information of a target or multiple targets is added. By acting as an inverse optical transfer function, the hologram gathers the target information to single point, and removes non-target background. Amplification is done by using a laser-illuminated hologram to create a phase-amplitude filter in a photorefractive material at the transform plane. By mixing the hologram and the scene at the transform plane, the matching is enhanced regardless of target location in the scene.