1010results about "Holographic light sources/light beam properties" patented technology

The invention relates to holographic head-up displays, to holographic optical sights, and also to 3D holographic image displays. We describe a holographic head-up display and a holographic optical sight, for displaying, in an eye box of the display / sight, a virtual image comprising one or more substantially two-dimensional images, the head-up display comprising: a laser light source; a spatial light modulator (SLM) to display a hologram of the two-dimensional images; illumination optics in an optical path between said laser light source and said SLM to illuminate said SLM; and imaging optics to image a plane of said SLM comprising said hologram into an SLM image plane in said eye box such that the lens of the eye of an observer of said head-up display performs a space-frequency transform of said hologram on said SLM to generate an image within said observer's eye corresponding to the two-dimensional images.

A method and system of interference lithography (also known as interferometric lithography or holographic lithography) which utilizes phase-locked, scanning beams (so-called scanning beam interference lithography, or SBIL). The invention utilizes a high-precision stage that moves a substrate under overlapped and interfering pairs of coherent beams. The overlapped beams interfere, generating fringes, which form a pattern “brush” for subsequent writing of periodic and quasi-periodic patterns on the substrate. The phase of the fringes in the overlapped region is phase-locked to the motion of the precision stage. The invention includes methods for forming, overlapping, and phase-locking interfering pairs of beams on a variety of substrates; methods for measuring and controlling the period, phase, and angular orientation of fringes generated by the overlapping beams; and methods for measuring and controlling the effects of stage mechanical and thermal drift and other disturbances during the writing process.

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.

A device for holographic reconstruction of three-dimensional scenes includes optical focusing means which directs sufficiently coherent light from light means to the eyes of at least one observer via a spatial light modulator that is encoded with holographic information. The device has a plurality of illumination units for illuminating the surface of the spatial light modulator (SLM); each unit comprises a focusing element (21 / 22 / 23 or 24), and a light means (LS1 / LS2 / LS3 or LS4) that emits sufficiently coherent light such that each of these illumination units illuminates one separate illuminated region (R1 / R2 / R3 or R4) of the surface, whereby the focusing element and the light means are arranged such that the light emitted by the light means (LS1-LS4) coincides close to or at the observer eyes.

A microscope is disclosed which determines a complex three-dimensional representation of an object based on a series of recordings of the light wave diffracted by the object, wherein the direction of the wave lighting of the object varies between two succesive recordings. The diffracted wave interferes with a reference wave on a receiving surface and a frequency representation of the diffracted wave is computed from interference patterns received on the receiving surface. A plurality of frequency representations of diffracted waves are then superimposed yielding a frequency representation of the object. The phase of each frequency representation of a diffracted wave is shifted in order to compensate for variations of the phase difference between the reference wave and the wave lighting of the object.

An illumination panel for illuminating an object, comprising a substrate, a light diffractive grating and a light source. The substrate is made from an optically transparent material having first and second area surfaces disposed substantially parallel to each other and a light input surface for conducting a light beam into the substrate. The light diffractive grating is mounted to the first areal surface and has a slanted fringe structure embodied therein for diffracting the light beam falling incident thereto, along a first diffractive order of the slanted fringe structure. The light source produces a light beam for transmission through the input surface and direct passage through the substrate to the slanted fringe structure so as to produce an output light beam of areal extent that emerges from either the first or second areal surface along the first diffractive order, for use in illuminating an object. A spatial-intensity modulation panel can be mounted to the illumination panel to form a color image display device. In the illustrative embodiments, the light diffractive grating is a volume hologram that is pixelated and spectrally-tuned in order to carry out spectral filtering functions within the color image display device.

A system for the production of a dynamic image for use in holography includes a light source (16) which travels via a liquid crystal modulator (18) placed in the path of the light source (16). The output of the LC modulator (18) passes modulated light through a lens array (22) which itself guides light to an optically addressed spatial light modulator (24). The resulting real image from the optically addressed spatial light modulator (24) may be used in holography. The addressing frame-rate of the liquid crystal modulator (18) is substantially greater than the frame-rate of the optically addressed spatial light modulator (24).

A display panel assembly comprises a transflective holographic screen, i.e., a transparent screen that reflects light from a projection system, comprising at least a volume hologram, a first protective element and a second protective element, each arranged in contact with the volume hologram such that the volume hologram is sandwiched between the first protective element and the second protective element. The display panel assembly further comprises a projection system focusing an image on the volume hologram comprising at least projection optics, mounting means arranged to fixedly mount the projection system relatively to the transflective holographic screen. The volume hologram comprises a plurality of diffractive patterns disposed in sequence across the volume hologram, each of the plurality of diffractive patterns being configured to diffuse the light rays from the projection system in a determined direction corresponding to the specific diffractive pattern and oriented towards a position of an intended eye of a user wearing the display panel assembly.

A method and system are disclosed for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process use thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence, while maximizing the contrast of the slanted fringe structures thereof. Different recording techniques are employed when the index of refraction of the substrate is greater than that of the recording medium, than when the index of refraction of the substrate is less than that of the recording medium. A recording and playback system of complementary design is provided for recording slanted-fringe volume holograms under relaxed conditions, without compromising the light diffraction efficiency of the holograms under different playback conditions.

A 3D display device with controllable device for tracking visibility regions is disclosed, and includes a controllable device for tracking a visibility region, generated by way of superposition of light source images, in a observer plane of the display device. In preferred embodiments, the cladding of a waveguide comprises at least one material with optical properties of an anisotropic liquid, or at least two materials with optical properties of an isotropic liquid; a matrix arrangement of control electrodes defines multiple positions to be generated for local exit points in the cladding of the waveguide at which the total reflection is locally cancelled; and a system controller modifies positions of the output coupling points for superposing the output-coupled light through the lens array to the visibility region by displacing an output coupling point, or by switching off one output coupling point and switching on another one.

Provided are an optically addressable spatial light modulator (OASLM) divided into a plurality of segments, and an apparatus and method for displaying a holographic three-dimensional (3D) image using the OASLM. The holographic 3D image display apparatus includes a first light source which emits a write beam, an electric addressable spatial light modulator (EASLM) which modulates the write beam emitted from the first light source according to hologram information regarding a 3D image, a second light source which emits a read beam, an OASLM which receives the write beam modulated by the EASLM and modulates the read beam emitted from the second light source according to hologram information included in the modulated write beam, a scanning optical unit which projects the write beam modulated by the EASLM onto the OASLM, and a Fourier lens which focuses the read beam modulated by the OASLM onto a predetermined space to form the 3D image.

Disclosed is a high resolution display on which decompressed high resolution image data is displayed, the display including pixels, the pixels being on a substrate, where circuitry is present on the same substrate as the pixels, where compressed high resolution image data which has been compressed using known data compression techniques is received by the circuitry, the circuitry being operable to perform decompression calculations which provide subsequent display of decompressed high resolution image data by the pixels of the display.

The data defining an object to be holographically reconstructed is first arranged into a number of virtual section layers, each layer defining a two-dimensional object data sets, such that a video hologram data set can be calculated from some or all of these two-dimensional object data sets. The first step is to transform each two-dimensional object data set to a two-dimensional wave field distribution. This wave field distribution is calculated for a virtual observer window in a reference layer at a finite distance from the video hologram layer. Next, the calculated two-dimensional wave field distributions for the virtual observer window, for all two-dimensional object data sets of section layers, are added to define an aggregated observer window data set. Then, the aggregated observer window data set is transformed from the reference layer to the video hologram layer, to generate the video hologram data set for the computer-generated video hologram.

A holographic display device comprising at least one magneto-optical spatial light modulator (MOSLM). The holographic display device may comprise a first MOSLM and a second MOSLM, the first and second MOSLMs encoding a hologram and a holographic reconstruction being generated by the device. An advantage of the device is fast encoding of holograms.

A series of holograms is recorded by synchronizing a camera with laser pulses under the control of a digital delay generator. Amplitude and phase images are calculated while image distances are adjusted for the best focus on the object under observation. The amplitude and phase images are reconstructed while adjusting the image distances over a predetermined range to maintain the object in focus. Numerical superposition of a plurality of holographic fields taken with varying wavelengths provides high resolution microscopic three-dimensional imaging. Numerical reconstruction is based on an angular spectrum method that enables calculation of the image at any distance from the hologram plane. Wavelength scanning digital interference holography also enables image reconstruction along an arbitrarily tilted plane.

A volume-phase reflection hologram optical element is fabricated by exposing a hologram photosensitive material to two coherent light beams. One exposure light beam has an axis-asymmetric wavefront, and the other exposure light beam has focus points different in the optical axis direction (Z-direction) between on a plane (ZX-plane) including one of two directions (X- and Y-directions) mutually perpendicular on a sectional plane perpendicular to that light beam and on a plane (YZ-plane) including the other of those two directions. Thus, an image display apparatus is realized in which at the time of reproduction, the component of a predetermined wavelength of the image light diffraction-reflected by the hologram optical element is focused at positions different in the optical axis direction between on the ZX-plane and on the YZ-plane, offering different image viewing characteristics between in the X- and Y-directions.

The present invention is related to a compact microscope able to work in digital holography for obtaining high quality 3D images of samples, including fluorescent samples and relatively thick samples such as biological samples, said microscope comprising illumination means (1,41) at least partially spatially coherent for illuminating a sample (2) to be studied and a differential interferometer (5) for generating interfering beams from said sample (2) on the sensor (33) of an electronic imaging device (7), said interferometer (5) comprising namely tilting means (17) for tilting by a defined angle one the interfering beams (28 or 29) relatively to the other, said tilting resulting into a defined shift (27) of said interfering beam on the sensor of the electronic imaging device (7), said shift (27) being smaller than spatial coherence width of each beam, said microscope being able to be quasi totally preadjusted independently from the samples so that minimum additional adjustments are required for obtaining reliable 3D images of samples.

A holographic display comprising light sources (L51, L52, . . . ) in a 2D light source array, lenses (L1, L2, . . . ) in a 2D lens array, a spatial light modulator (SLM) and a beamsplitter, in which there are m light sources per lens, and the light sources are in m-to-one correspondence with the lenses. The beamsplitter splits the rays leaving the SLM into two bundles, one of which illuminates the virtual observer windows for m left eyes (VOWL) and the other illuminates the virtual observer windows for m right eyes (VOWR). In one example, m=1. An advantage is 2D-encoding with vertical and horizontal focusing and vertical and horizontal motion parallax.

A holographic direct-view display system uses holographic integral imaging techniques that is an auto stereoscopic way to reproduce parallax and occlusion. The display is not resolution limited and is scalable to display life size images if desired. The system can be used to transmit 3D depictions of a scene at video and sub-video rates as well as other information, such as images of documents or computer generated images. The images may be captured, transmitted and displayed in real-time (or near real-time) for telepresence or stored for time-shifted display. The system combines integral holography, a pulsed laser to record the hologram at high speed and a dynamic refreshable holographic material such as a photorefractive polymer as a recording media. The system uses techniques to write, read and erase the updateable hologram that allow the holographic material, hence direct-view display to remain stationary throughout each of the processes for continuous presentation of the hologram to the audience. The system may write, read and erase at the same time and continuously to increase throughput. This system may also use additional novel techniques to improve brightness, efficiently implement a full-parallax display and to implement a full-color display in a transmission geometry.

A laser beam is reflected by a light beam scanning device and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a linear scatter body is recorded as a hologram by using reference light that converges on a scanning origin. The light beam scanning device bends the laser beam at the scanning origin and irradiates the laser beam onto the hologram recording medium. At this time, by changing a bending mode of the laser beam with time, an irradiation position of the bent laser beam on the hologram recording medium is changed with time. Diffracted light from the hologram recording medium produces a reproduction image of the linear scatter body on a light receiving surface of the stage. When an object is placed on the light receiving surface, a line pattern is projected by hologram reproduction light, so that the projected image is captured and a three-dimensional shape of the object is measured.

A method of producing a hologram element is disclosed that is able to prevent spread of a polymerization reaction and light leakage during exposure with interference light, and improve productivity in mass production. The hologram element is for transmitting, reflecting, diffracting, or scattering incident light, and includes a pair of substrates, an isolation member between the substrates that forms an isolated region, and a photo-sensitive recording material sealed in the isolated region. The hologram element includes a periodic structure formed by exposing the recording material to interference light. The interference light is generated by two or more light beams, or by using a master hologram. The recording material is formed from a composite material including a polymerized polymer or a polymerized liquid crystal. The periodic structure is formed by exposing the recording material to the interference light to induce the polymerization reaction and phase separation in the composite material.

The invention provides apparatus and methods for detecting objects in samples. The sample is held in the transmission path of light from a light source to a detector, whereby light from the light source interacts with objects in the sample. The patterns of light incident on the detector subsequent to its interaction with the objects are directly used to determine the presence of objects in the sample.

A method and a device for encoding and reconstructing computer-generated video holograms using a conventional LC display: it provides holographic reconstruction of three-dimensional scenes using electronically controllable pixel in a holographic array (3) with a conventional resolution, and is reasonably free from flickering and cross-talk. Reconstruction is in real time, and for both eyes at the same time, over a large viewing zone. The method takes advantage of an optical focusing means (2) in order to image vertically coherent light emitted by a line light source (1) into viewing windows (8R, 8L) after modulation by the pixel array (3). The holographic reconstruction (11) of the scene is rendered visible from viewing windows (8R, 8L) for both eyes of an observer by way of diffraction at the pixels. According to the invention, the controllable pixels are disposed in vertical pixel columns (15, 16), which encode separate holograms of the same scene for each of the viewer's eyes (R, L), where said holograms are one-dimensional in the vertical direction and horizontally interleaved. An image separation means (7) with separating elements arranged parallel to the pixel columns reveals the respective pixel columns (15, 15′ or 16, 16′) for one eye and covers them for the other eye.

A backlight unit (BLU), for a binocular holographic display apparatus, and the binocular holographic display apparatus including the BLU are provided. The BLU includes: a light source unit that emits coherent illumination light; and a light guide plate that is transparent and includes a light incidence surface onto which the coherent illumination light emitted by the light source unit is incident and a light emission surface through which the illumination light is output. The light source unit includes a beam deflector that adjusts an incidence angle of the illumination light incident onto the light guide plate.

Variation of the wavelength of the light emitted from a light source is reduced by a wavelength variation reduction mechanism. Hence, wavelength deviation of the intensity peak of the light emitted from the light source from the diffraction-efficiency peak of a hologram optical element is reduced. Thus, even when a high-brightness light source is used, the light emitted therefrom can be diffracted with the hologram optical element efficiently. Moreover, the heat generated by the light source is efficiently rejected through the surface of a land portion of a flexible printed circuit, is then, via an insulating layer of the flexible printed circuit, efficiently absorbed through the surface of a heat absorbing member, and is then, via a shield conductor, led out of a casing, so as to be thereby expelled.

The invention relates to a display device for holographic reconstruction. The display device comprises a spatial light modulator device having combined phase modulating pixels and amplitude modulating pixels, an illumination unit generating sufficiently coherent light and arranged to illuminate of the spatial light modulator device and a reflection plane. The device being arranged such that light enters the spatial light modulator device and passes both the phase modulating pixel and the amplitude modulating pixel of the spatial light modulator device. The light is reflected by the reflection plane in between.

A device (1) for sorting objects immersed in a flowing medium is described. The device comprises a holographic imaging unit comprising a plurality of holographic imaging elements (2), a fluid handling unit comprising a plurality of microfluidic channels (3) for conducting flowing medium along a corresponding holographic imaging element (2) and comprising a microfluidic switch (5) arranged downstream of an imaging region in the microfluidic channel for controllably directing each object in the flowing medium into a selected one of a plurality of outlets (6). The device also comprises a processing unit (7) adapted for real-time characterization of the holographic diffraction image obtained for each of the objects thereby taking into account at least one predetermined object type signature. The processing unit (7) furthermore is adapted for controlling the microfluidic switch (5) in response to the characterization.