Abstract: A laser beam generated by a laser light source is reflected by a light beam scanning device and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a scatter plate 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, scanning is carried out by changing a bending mode of the laser beam with time so that an irradiation position of the bent laser beam on the hologram recording medium changes with time. Regardless of an irradiation position of the beam, diffracted light from the hologram recording medium produces a reproduction image of the scatter plate on the spatial light modulator. The modulated image of the spatial light modulator is projected onto a screen by a projection optical system.

Abstract: An optical observation device with at least one visual observation beam path, includes an objective lens, an eyepiece, an Abbe König prism system, Porro prism system or Schmidt Pechan prism system, arranged in the at least one visual observation beam path between the objective lens and the eyepiece, a display device for displaying an additional image in the visual observation beam path to the observer, and a device for image superposition, which has a holographic optical element, and which uses the holographic optical element to superpose onto the image of the display device the image of a target object to be observed in an intermediate image plane of the visual observation beam path. The prism system is provided with the at least one holographic element of the at least one device for image superposition.

Abstract: The invention relates to a device for superimposing an image in the beam path of an aiming optics, having an at least partially transparent optical support element which is arranged in the beam path of the aiming optics and has at least one diffractive optical coupling element and at least one diffractive optical decoupling element, the at least one diffractive optical coupling element leading light of the image to be superimposed, which light is incident on said coupling element and is to be coupled in, through the optical support element to the at least one diffractive optical decoupling element for the purpose of superimposition with the beam path. The image to be superimposed is imaged into the beam path of the aiming optics by the at least one diffractive optical coupling element and the least one diffractive optical decoupling element.

Abstract: A device for producing a reflection hologram by means of a master, which is formed by a substrate on which a saw-toothed shaped structure is formed by molding, mechanical or lithographical methods. The structure has a reflective finish, such that the desired surface is produced on the structure. The light of a laser light source is expanded by means of an optical device, thus enabling a beam having a predetermined beam width to be obtained. The beam radiates the master and is reflected by the structure at an angle ? in relation to the incident beam. Above the smooth surface arranged over the structure a photopolymer-film, containing a photo-sensitive layer that is disposed at a distance in relation to the structure, is arranged and the reflection hologram is produced in the photo-sensitive layer.

Abstract: A device for correcting the wavelength dependence in diffraction-based optical systems in which certain orders of diffraction are filtered is disclosed, comprising at least one diffractive optical spatial light modulator that has controllable structures, and at least one light source for illuminating the spatial light modulator. Associated orders of diffraction are created which, depending on the wavelength, have a lateral chromatic offset relative to the position of the different extensions thereof on a filter plane defined by the focal length of a downstream optically focusing system, the lateral chromatic offset being in relation to the normal line to the surface of the spatial light modulator. The equinumerous orders of diffraction of different wavelengths overlap to an sufficient extent on a predefined filter plane in relation to both the direction and the extension thereof.

Abstract: A virtual image display device with an optical waveguide to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: Method for real-time rendering and generating of computer-generated video holograms from three-dimensional image data with depth information, where the position and viewing direction of an observer defines a view of the scene, and where the observer is assigned with at least one virtual observer window, which is situated in an observer plane near the observer eyes, comprising the following process steps: 3D rendering and generation of the depth map of scene section data between two parallel section planes, which are disposed at right angles to the viewing direction of the observer, transformation of the scene section data, repetition of the steps of 3D rendering and transformation, Back-transformation, encoding in pixel values in order to reconstruct the three-dimensional scene.

Abstract: A computer generated hologram which forms a light intensity distribution on a predetermined plane by giving a phase distribution to a wavefront of incident light, the hologram comprising a plurality of anisotropic cells each including an anisotropic medium configured to change a polarization state of the incident light, and a plurality of isotropic cells each including an isotropic medium configured not to change a polarization state of the incident light, wherein a linearly polarized light component, in a first direction, of the incident light forms a first light intensity distribution on the predetermined plane, and a linearly polarized light component, in a second direction perpendicular to the first direction, of the incident light forms a second light intensity distribution different from the first light intensity distribution on the predetermined plane.

Abstract: Methods and apparatus (1100) for trapping fluid-borne object(s) (212) using one or more Fresnel zone plates (202) located in proximity to a fluid medium (208). Optical tweezers based on one or more Fresnel zone plates may be integrated with a microfluidic structure (e.g., chambers, channels) (1104) of various geometries so as to form one or more optical traps (215) within a fluid medium contained by the microfluidic structure(s). Three-dimensional trapping of objects can be obtained with stiffness comparable to that of conventional optical tweezers based on a microscope objective. In one example, a single Fresnel zone plate is particularly configured to form multiple optical traps upon irradiation, so as to trap multiple objects simultaneously. Exemplary applications of the methods and apparatus disclosed herein include determination of various fluid medium properties (e.g., velocity, refractive index, viscosity, temperature, pH) and object sorting.

Abstract: Light modulator displays may be illuminated using a light guide comprising diffractive optics that directs light onto the light modulators. The light guide may comprise, for example, a holographic light turning element that turns light propagating within the light guide onto the array of light modulators. In some embodiments, the holographic element has multiple holographic functions. For example, the holographic element may additionally collimate ambient light or diffuse light reflected form the light modulators.

Abstract: A method of fabricating a switchable liquid crystal polarization grating includes creating a degenerate planar anchoring condition on a surface of a reflective substrate. An alignment layer may be formed on a transmissive substrate and may be patterned to create a periodic alignment condition therein. The transmissive substrate including the patterned alignment layer thereon may be assembled adjacent to the surface of the reflective substrate including the degenerate planar anchoring condition thereon to define a gap therebetween. A liquid crystal layer is formed on the surface of the reflective substrate including the degenerate planar alignment condition. The liquid crystal layer may be formed in the gap directly on the alignment layer such that molecules of the liquid crystal layer are aligned based on the periodic alignment condition in the alignment layer. Related fabrication methods and polarization gratings are also discussed.

Abstract: An optical device for directing illuminating light at a pixel matrix and/or at a controllable spatial light modulator of a display, in particular of a stereoscopic or holographic 3D display comprises a multitude of reflection elements which work according to the principle of a concave mirror and which direct the illuminating light at the pixel matrix and/or at the controllable spatial light modulator of the display, and/or comprises at least one transmission element which is designed in the form of a holographic optical element, in particular in the form of a holographic volume grating, which directs the illuminating light at the pixel matrix and/or at the controllable spatial light modulator of the display.

Abstract: A volume holographic imaging system enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) object. The 4D source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam. A phase mask is encoded in one or more multiplexed holographic gratings of the holographic element using a spatial filter. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from a corresponding slice of the 4D probing source object to a non-overlapping region of the detector.

Abstract: A volume holographic imaging system, apparatus, and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object. A 4D probing source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. A 4-f telecentric relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.

Abstract: A volume holographic imaging system, apparatus and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object A 4D probing source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. A 4-f telecentric relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.

Abstract: A system for path compensation of multiple incoherent spectral optical beams incorporates an optical element combining a plurality of incoherent spectral beams to an aperture by angle using carrier frequency tilt fringes. An illumination laser is employed for reflection of an illumination beam from a target. An interferometer receives a sample of the reflected illumination beam reflected from the target and provides interference fringes. A spatial light modulator receives the interference fringes and generates a real time hologram. Relay optics are employed for transmitting the combined plurality of incoherent beams to the SLM and receiving a diffraction corrected full aperture compensated combined beam for emission to the far field.

Abstract: The invention relates to a controllable illumination device for an autostereoscopic or holographic display, which illumination device contains an illumination matrix of primary light sources having at least one luminous element per light source and a controllable light modulator (SLM) and a reproduction matrix. A computer-generated hologram (CGH) illuminated by the primary light sources (11, . . . , 1n) is coded on the controllable light modulator (SLM) and generates, in at least one plane downstream of the SLM, a matrix—reconstructed from the computer-generated hologram (CGH)—of secondary light sources (2) having a secondary light distribution for the purpose of illuminating the reproduction matrix (4) and for the purpose of focussing in light bundles onto each eye of the viewer via an imaging matrix. The CGH is calculated and reconstructed on the basis of the number of and the positions of the viewers and the system parameters.

Abstract: A method and system for performing three-dimensional holographic microscopy of an optically trapped one dimensional structure. The method and system use an inverted optical microscope, a laser source which generates a trapping laser beam wherein the laser beam is focused by an objective lens into a plurality of optical traps. The method and system also use a collimated laser at an imaging wavelength to illuminate the structure created by the optical traps. Imaging light scattered by the optically tapped structure forms normalized intensity holograms that are imaged by a video camera and analyzed by optical formalisms to determine light field to reconstruct 3-D images for analysis and evaluation.

Abstract: Various embodiments related to monitoring for optical faults in an optical system are disclosed. For example, one disclosed embodiment provides, in an optical system comprising a light source, a light outlet, and an optical element disposed between the light source and the light outlet, a method of monitoring for optical system faults. The method includes detecting, via a light sensor directed toward an interface surface of the optical element closest to the light source, an intensity of light traveling from the interface surface of the optical element to the light sensor, and comparing an intensity of light detected to one or more threshold intensity values. The method further includes identifying an optical system fault condition based on comparing the intensity of light detected to one or more threshold values, and modifying operation of the optical system.

Abstract: A volume holographic imaging system, apparatus, and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object A 4D probing source object is illuminated to emit or scatter an optical field A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information A 4-ftelecent?c relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object The focused 2D slice is projected onto a 2D imaging plane The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.

Abstract: An image display device which enables tracking of a viewer and is convertible into a 2D display mode without loss of viewing angle, includes an image panel to emit a 2-dimensional (2D) image, a backlight unit to direct collimated light to the image panel, a scattered-light converting cell provided over the backlight unit, the scattered-light converting cell to scatter the collimated light upon 2D display and to directly emit the collimated light upon 3D display, and a holographic optical element provided over the backlight unit, the holographic optical element to adjust an optical path so as to set a viewing window to a position of a viewer upon 3D display.

Abstract: Blazing of real time holographic fringes employs an interferometer with a focal plane array (FPA) to receive interference fringes. An FPA frame is read into a fringe processor. For each row, minima are identified and a pixel value is saved and its position in the row recorded. The minima determination is repeated for each column in the row until all pixels in the row have been recorded. A blazed fringe for the single row is then created. The blazed fringe row is then transferred to a spatial light modulator (SLM). The minima determination and fringe blazing processes are repeated until all rows in the FPA array are read and transferred to the SLM. The next FPA frame is then read into the fringe processor.

Abstract: A diffractive beam expander (50) comprises a substantially planar waveguiding substrate, an input grating (10) to provide an in-coupled beam (B1) propagating within said substrate, and an output grating (30) to provide an out-coupled beam. The expander (50) comprises also four or more further grating portions to expand the height of the in-coupled beam (B1). A part of the in-coupled light is diffracted by a first deflecting grating portion (21a) to provide a first deflected beam. A part of the in-coupled light is diffracted by a second deflecting grating portion (22a) to provide a second deflected beam. The first deflected beam propagates downwards and the second deflected beam propagates upwards with respect to the in-coupled beam (B1). The first deflected beam impinges on a first direction-restoring grating portion (21b) and the second deflected beam impinges on a second direction-restoring grating portion (22b).

Abstract: The invention provides a car lighting unit comprising a reflector and a light source arranged to generate light. The reflector circumferentially surrounds the light source and has a reflector opening. The reflector is arranged to reflect at least part of the light from the light source through the reflector opening. The car lighting unit further comprises a source-related 3D hologram and a source-unrelated 3D hologram. The car lighting unit is 5 constructed to generate a beam of light and a source-related holographic 3D image, using light from the light source, during operation of the lighting unit, and a source-unrelated 3D holographic image when the lighting unit is not in operation.

Abstract: Optical solenoid beams, diffractionless solutions of the Helmholtz equation whose diffraction-limited in-plane intensity peak spirals around the optical axis, and whose wavefronts carry an independent helical pitch. The solenoid beams have the noteworthy property of being able to exert forces on illuminated objects that are directed opposite to the direction of the light's propagation. Optical solenoid beams therefore act as true tractor beams that are capable of transporting material back toward their source.

Abstract: There is provided an optical multiplexer including: a substrate having a plurality of beam transmitting portions; and diffraction gratings diffracting beams irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion. Accordingly, it is possible to reduce an alignment error and manufacturing cost and to reduce the entire size of a recording apparatus or a reproducing apparatus.

Abstract: Continuous Adjustable 3Deeps Filter Spectacles are provided with lenses with continuously changeable optical densities, so that viewing of 2D movies is optimized for visualization in natural 3D. Method and means are disclosed for the continuous Adjustable 3Deeps Filter Spectacles to perform two independent optimizations to achieve optimized 3Deep visual effects on 2D movies. First they compute the optical density setting of the lenses for optimal viewing of 2D movies as 3D. Then they continuously render the lenses of the spectacles to these optical densities optimized for characteristics of the electro-optical material from which the lenses of the spectacles are fabricated. The invention works for both 3DTV and 3D Cinema theater viewing.

Abstract: A lighting device is disclosed which provides for an adjustable beam. The adjustable beam involves the use of a hologram diffuser with areas that have different diffusing properties. The different diffusing areas are selectively positionable in a light beam created by the lighting device to provide for an adjustable beam by providing different diffusions of the light.

Abstract: A method and apparatus for selecting a specific fraction from a heterogeneous fluid-borne sample using optical gradient forces in a microfluidic or fluidic system are presented. Samples may range in size from a few nanometers to at least tens of micrometers, may be dispersed in any fluid medium, and may be sorted on the basis of size, shape, optical characteristics, charge, and other physical properties. The selection process involves passive transport through optical intensity field driven by flowing fluid, and so offers several advantages over competing techniques. These include continuous rather than batch-mode operation, continuous and dynamic tunability, operation over a wide range of samples, compactness, and low cost.

Abstract: A three-dimensional image display device is provided which allows a reduction in redundant calculation and high-speed obtainment of an optimum control image to be recorded on an optical wavefront control unit This invention relates to a three-dimensional image display device for displaying a three-dimensional image by irradiating illuminating light at an optical wavefront control unit which records a control image. The three-dimensional image display device of this invention includes a control image optimizing unit which calculates three-dimensional images corresponding to a group of control images based on constraints inherent to the optical wavefront control unit, selects a control image corresponding to a three-dimensional image satisfying a predetermined condition from the group of control images and records the selected control image on the optical wavefront control device.

Abstract: A method of focusing radiation with an array of lenses, which includes modifying the angles of propagation and convergence and/or divergence with transmission and reflection holographic optical elements, and coupling the radiation into an optical fiber.

Abstract: A system for path compensation of multiple incoherent optical beams incorporates an optical element combining a plurality of incoherent beams to an aperture by angle using carrier frequency tilt fringes. An illumination laser is employed for reflection of an illumination beam from a target. An interferometer receives a sample of the reflected illumination beam reflected from the target and provides interference fringes. A spatial light modulator receives the interference fringes and generates a real time hologram. Relay optics are employed for transmitting the combined plurality of incoherent beams to the SLM and receiving a diffraction corrected full aperture compensated combined beam for emission to the far field.

Abstract: A transmission type optical element comprising a first hologram having a first surface and a second surfaces and a second hologram having a third surface and a fourth surface. The first surface of the first hologram and the third surface of the second hologram are oppositely arranged. A first light beam having a first wavelength is made to enter the first hologram from the side of the second surface. It is transmitted through the first hologram and exits the first hologram from the side of the first surface. The light beam then enters the second hologram from the side of the third surface. It is diffracted by the second hologram and exits the second hologram from the side of the third surface. The light beam then enters the first hologram from the side of the first surface and is diffracted by the first hologram.

Abstract: An image display device includes an image forming device, collimating optical system, and optical device, with the optical device including a light guide plate, first diffraction grating member and second diffraction grating member which are made up of a volume hologram diffraction grating, and with central light emitted from the pixel of the center of the image forming device and passed through the center of the collimating optical system being input to the light guide plate from the near side of the second diffraction grating member with a certain angle. Thus, the image display device capable of preventing occurrence of color irregularities, despite the simple configuration, can be provided.

Abstract: A hologram layer (13) is irradiated by light from an optical element (10). The hologram layer (13) is provided with a first hologram (14) that diffracts in a predetermined direction, from among incident light from the optical element (10), X-polarized light in which the polarization component is in a specific direction and emits the light as X-polarized light of a first phase state (P1), and a second hologram (15) that both diffracts in the same direction as the X-polarized light of the first phase state (P1) and moreover at an equal radiation angle, from among incident light from the optical element (10), Y-polarized light in which the polarization component is in a direction orthogonal to that of the X-polarized light and converts it to X-polarized light, and emits the light as X-polarized light of a second phase state (P2) that differs from the first phase state (P1).

Abstract: The present invention is directed toward a system and method for projecting holographic optical traps whose intensity maxima are extended along specified paths in three dimensions with specified amplitude and phase profiles along those paths. Specifying paths that constitute knotted loops and phase profiles that direct radiation pressure along the knotted paths yields optical traps that exert knotted force fields. Knotted optical force fields have uses for inducing motion along knotted paths, with applications including the generation of knotted electric current loops in plasmas.

Abstract: In an optical head device which performs recording or reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording or reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The above optical element is integrally combined with the objective lens to perform a tracking servo following operation.

Abstract: A compact illumination optical system manufactured at reasonable cost can be provided. The illumination optical system can include: a light source for emitting a light beam; a hologram element for converting the light beam emitted from the light source to reproduced light having a predetermined shape of light distribution and a predetermined luminance distribution; a fluorescent plate containing a fluorescent material for emitting visible light by absorbing the reproduced light emitted from the hologram element and entering the fluorescent material; and a lens for projecting forward the visible light emitted from the fluorescent plate.

Abstract: An arrangement utilizes diffractive, reflective and/or refractive optical elements combined to intensify and homogenize electromagnetic energy, such as natural sunlight in the terrestrial environment, for purposes such as irradiating a target area with concentrated homogenized energy. A heat activated safety mechanism is also described.

Abstract: An optical element is provided with: first polarization-separation layer (13) that is laminated on first surface (12b) of light guide body (12) and that, of the light incident from light guide body (12), transmits X-polarized light and reflects Y-polarized light that is orthogonal to the X-polarized light; polarization hologram layer (14) that is laminated on first polarization-separation layer (13) and that diffracts to a prescribed diffraction angle the X-polarized light that is incident within a prescribed range of angles of incidence and converts the X-polarized light to Y-polarized light; second polarization-separation layer (15) that is laminated on polarization hologram layer (14) and that, of the light incident from polarization hologram layer (14) transmits Y-polarized light and reflects X-polarized light; reflection layer (18) provided on second surface (12c) side of light guide body (12); and phase difference layer (17) that is provided between first surface (12b) of light guide body (12) and refle

Abstract: An Interferometer for off-axis digital holographic microscopy includes a recording plane, and a grating located in a plane optically conjugated with the recording plane. The grating defining a first and a second optical path, the optical path corresponding to different diffraction order.

Abstract: A volume hologram recording material is located on the side of a reflection type volume hologram master onto which copying illumination light is incident, and the copying illumination light incident onto the recording material and light diffracted through the master interfere together in the volume hologram recording material thereby copying the reflection type volume hologram master. In this case, a reflecting plate having a fine regular reflection pattern is interleaved between the master and the recording material, and the copying illumination light incident onto the recording material and regularly reflected light from the reflecting plate having the regular reflection pattern interfere together in the recording material thereby allowing the regular reflection pattern to be multi-recorded in a hologram having the reflection type volume hologram master copied in it.

Abstract: A solar light concentration plate comprises a first hologram which receives solar light and diffracts incident light in a range of an incident angle, and first and second light guides respectively disposed on both sides of the first hologram, wherein at least one of the first and second light guides has an outer surface substantially inclined to an inner surface of the at least one of the first and second light guides.

Abstract: The exposure method includes the steps of: illuminating a hologram recording medium, in which a hologram with a first pattern has been recorded by illumination with a laser beam emitted from a first laser oscillator, with a laser beam emitted from a second laser oscillator; and delivering the laser beam emitted from the second laser oscillator, which has passed through the hologram recording medium, onto a resist, thereby forming a second pattern in the resist. The wavelength of the laser beam used for illuminating the resist through the hologram recording medium in which the hologram is recorded is shorter than the wavelength of the laser beam used for recording the hologram in the hologram recording medium. Further, the wavelength of the laser beam used for illuminating the resist is 1/(0.5×n) (where n is an integer not less than 3) that of the laser beam used for recording the hologram.

Abstract: An apparatus for providing an optical display includes an optical substrate for propagating light received from a light source, a first set of one or more switchable diffractive elements in the substrate, and a second set of one or more switchable diffractive elements in the substrate. Each diffractive element in the second set corresponds to a diffractive element in the first set. Each of the diffractive elements in the first and second sets is configured to switch between on and off states. One of the states is for diffracting light and the other state for allowing light to pass through. Each of the first set of diffractive elements is configured to diffract the light at an angle for propagation in the substrate. Each of the second set of diffractive elements is configured to diffract the light for display.

Abstract: An image display device includes a light source which emits laser light; an optical element which is operable to switch between a first state for reducing a coherence of the laser light and a second state for substantially maintaining the coherence of the laser light; a switching control circuit which controls the optical element; an imager which modulates the laser light transmitted through the optical element; and a modulation control circuit which controls the imager based on an image signal. The modulation control circuit causes the imager to render an image pattern for generating an image by changing alight amount at each pixel position when the optical element is in the first state, and causes the imager to render a hologram pattern for generating an image by diffraction when the optical element is in the second state.

Abstract: A substrate-guided holographic diffuser has a light-guide section configured to in-couple light and transmit the light within itself via total internal reflection. It can also have a brightness enhancement section that recycles non-diffracted light within the light-guide section. A hologram section that receives light from the light-guide section has a holographic structure defining acceptance conditions and is positioned relative to the internally reflected light such that the internally reflected light meets the acceptance conditions of the holographic structure. The internally reflected light is out-coupled by the holographic structure as a projected image of light scattered from a diffuser.

Abstract: A transmission type optical element comprising a first hologram having a first surface and a second surfaces and a second hologram having a third surface and a fourth surface. The first surface of the first hologram and the third surface of the second hologram are oppositely arranged. A first light beam having a first wavelength is made to enter the first hologram from the side of the second surface. It is transmitted through the first hologram and exits the first hologram from the side of the first surface. The light beam then enters the second hologram from the side of the third surface. It is diffracted by the second hologram and exits the second hologram from the side of the third surface. The light beam then enters the first hologram from the side of the first surface and is diffracted by the first hologram.

Abstract: The present invention pertains to compounds and polymers which incorporate a boronic acid sensor group (SG) of the formula (I): wherein: J is independently —CH2— or —CH2CH2—; n is independently 0, 1, 2, or 3; and each RR, if present, is independently a ring substituent; and wherein the ring attachment (i.e., where sensor group is attached) is via the 3-, 4-, 5-, or 6-ring position. Such compounds and polymers are useful in the selective chemical detection and/or quantitation of alpha-hydroxy carboxylic acids, such as lactic acid/lactate and malic acid/malate. The present invention also pertains to methods of preparing such compounds and polymers; methods and assays which employ these compounds and polymers; devices (e.g., holographic sensors) and kits for use in such methods and assays, etc.

Abstract: An Electrically Switchable Bragg Grating (ESBG) despeckler device comprising at least one ESBG element recorded in a hPDLC sandwiched between transparent substrates to which transparent conductive coatings have been applied. At least one of said coatings is patterned to provide a two-dimensional array of independently switchable ESBG pixels. Each ESBG pixel has a first unique speckle state under said first applied voltage and a second unique speckle state under said second applied voltage.