Abstract: A reflection grating includes a transmission hologram layer for diffracting incident light, a reflection member in contact with the transmission hologram layer, and a reflection plane for reflecting diffracted light generated by the transmission hologram layer.

Abstract: An optical system for holographic sights includes a laser diode, two mirrors, a holographic optical element (HOE) and a hologram. The two mirrors direct the diverging laser beam through a folded path to reach certain cross sectional area. The HOE filters, collimates and deflects the beam. Under the illumination of a collimated beam, the hologram projects a virtual reticle image at target plane. The HOE and the hologram are mounted in parallel and have the same period to achieve diffraction match so as to eliminate the image shift.

Abstract: A virtual image display device is provided which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide (13) to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating (14) 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 (15) 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: A diffractive coupling element based on a computer-generated hologram is used in an optical coupling system of a transmitter to control the launch of laser light from a laser light source onto an end of an optical fiber. The diffractive coupling element controls the launch of the laser light such that a desired optical intensity distribution pattern is provided that substantially avoids the center and edge refractive index defects contained in the optical fiber.

Abstract: A medium 1, that is a laminated holographic medium of the present invention is composed of two or more core layers 2; 3 or more cladding layers 3 set so as to bind the core layers 2; one or more diffraction grating layers 4 storing information data and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or set inside the core layers 2; and one or more recording layers 42 storing information data as forms or a refractive index distribution and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or inside the core layers 2 through or without a gap layer.

Abstract: The present invention provides a hologram which forms a light intensity distribution on a predetermined plane by using incident light. The hologram includes a plurality of cells configured to control both a phase of a first polarized light component in a first polarization direction of the incident light and a phase of a second polarized light component in a second polarization direction perpendicular to the first polarization direction, to form a phase difference distribution between phase distributions for the first and second polarized light components. The plurality of cells are designed so that a number of phase difference levels of the phase difference distribution is less than a number of phase levels of the phase distribution of the first polarized light component.

Abstract: The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

Abstract: A device that provides light beam switching, agile steering of the light beam over a range of angles, and generation of arbitrary wavefront shapes with high spatial and temporal resolution. The agile device can include a volume diffractive structure comprising Bragg planes having one refractive index and the Bragg planes separated by regions containing an active optical medium. Electrodes (which may be the Bragg planes themselves, or may be arrayed adjacent to the active optical medium) are used to control the electric field intensity and direction across the structure, and thereby control the diffraction efficiency of the structure and the local phase delay imposed on a diffracted wavefront. Means are provided for addressing the many thousands of electrodes required for precise and rapid wavefront control. Applications include free-space atmospheric optical communications, near-eye displays, direct-view 3D displays, optical switching, and a host of other applications.

Abstract: A virtual image display device which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes 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: Dual-function laser systems and methods are disclosed. In one implementation, an apparatus includes a laser source configured to emit a beam; a collimating optical system spaced apart from the laser source; and a diffractive element positioned to diffract the beam to provide a diffracted beam to the collimating optical system such that the collimating optical system refracts the diffracted beam to form an approximately collimated central portion and a diverging outer portion.

Abstract: A near-eye display related apparatus and device is disclosed. The apparatus includes a housing configured to receive an optical engine, and a light guiding plate attached to the housing and configured to receive light representing an image from the optical engine, the light guiding plate includes a first diffractive grating adapted to incouple the light into the light guiding plate, and a second diffractive grating adapted to outcouple the light from the light guiding plate such that the light is received by an eye of a user wearing the apparatus. The light guiding plate has a contact surface portion configured to optically couple the light guiding plate to a transparent plate, The contact surface portion being adapted to be in physical contact with the transparent plate.

Abstract: A laser alignment assembly has two or more lasers aligned relative to one or more reflective surfaces to generate coaligned and collimated light beams. The assembly may further make the light beams collinear. The orientation of the reflective surface may be controlled by an electrically controllable actuator. The laser alignment assembly may be disposed in a weapon aiming system having visible and infrared lasers and may be coupled to a weapon to aid in aiming of the weapon.

Abstract: 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.

Abstract: A total reflection surface and a holographic optical element (HOE) surface are formed on the same surface (S3) in an eyepiece prism (15). In this structure, a smaller reflection angle can be set at an HOE (16) compared to a structure with the surface formed separately, and the HOE surface of the surface (S3) can be set in the direction parallel to a surface (S2). Thus, even in a structure in which at least a portion of the light flux of the image light fully reflected by the surface (S3) is incident on an affixing region (R1) of a hologram photosensitive material (16a), that portion of the light can be prevented from falling incident on the optical pupil (E) as ghost light. Consequently, in order to prevent the generation of ghost light, an optical path margin no longer needs to be provided between the diffraction and reflection region of the HOE (16) and the total reflection region of the image light; and the eyepiece prism (15) can be thinned by that amount.

Abstract: A laser processing device 1 includes a laser light source 10, a spatial light modulator 20, a control section 22, and a condensing optical system 30. The spatial light modulator 20 is input with a laser light output from the laser light source 10, presents a hologram for modulating the phase of the laser light in each of a plurality of two-dimensionally arrayed pixels, and outputs the phase-modulated laser light. The control section 22 causes a part of the phase-modulated laser light (incident light) to be condensed at a condensing position existing in a processing region as a laser light (contribution light) having a constant energy not less than a predetermined threshold X.

Abstract: The invention disclosed here teaches methods to fabricate and utilize a non-dispersive holographic wavelength blocker. The invention enables the observation of the Raman signal near the excitation wavelength (˜9 cm?1) with the compactness of standard thin film/holographic notch filter. The novelty is contacting several individual volume holographic blocking notch filter (VHBF) to form one high optical density blocking filter without creating spurious multiple diffractions that degrade the filter performance. Such ultra-narrow-band VHBF can be used in existing compact Raman instruments and thus will help bring high-end research to a greater number of users at a lower cost.

Abstract: Light outputted from a laser light source (12) of an image generating section (11) is two-dimensionally deflected and permitted to perform scanning by means of a reflecting surface (13a) of a deflecting device (13), diffused by means of a diffusion unit (14), and then diffracted and reflected by an HOE (23) of an eyepiece optical system (4), and guided to an optical pupil (E). Deterioration of qualities of an observing image can be eliminated by setting the optical pupil (E) and the reflecting surface (13a) of the deflecting device (13) to have an optically conjugated positional relationship.

Abstract: Methods create images viewable under different selected angels on optical storage devices and other photosensitive surfaces and optical storage devices with super-imposed images. Generally, a photosensitive surface is exposed with multiple diffraction patterns creating super-imposed images. These diffraction patterns create super-imposed images on the photosensitive surfaces, which can be read by either a human or a computer.

Abstract: A hologram element that forms a predetermined illumination pattern on an irradiated surface by diffracting incident light is disclosed. The illumination pattern is formed by making light in a first wavelength region diffracted in a first region, and the illumination pattern is formed by making light in a second wavelength region different from the first wavelength region diffracted in a second region on the same plane as the first region.

Abstract: A photodetector integrated circuit (PDIC) capable of being used with at least two different types of optical discs includes a photodetector (PD) array and a switch matrix. The PD array includes a center channel PD and a side channel PD electrically isolated from the center channel PD. The switch matrix, which includes a plurality of inputs and a plurality of outputs, can be selectively configured in a plurality of different switch configurations. The side channel PD includes a plurality of electrically isolated PD sections. Each electrically isolated PD section of the side channel PD is adapted to detect light and provide an electrical output signal, indicative of the light detected by the PD section, to a different one of the inputs of the switch matrix.

Abstract: The light-enhancing system of the invention comprises a laser diode in which a fully reflecting mirror and/or a partially reflecting mirror of the laser diode is made in the form of digital planar holography (DPH) incorporating a mode-reorganization function that decreases divergence and improves brightness of the output beam of the system by suppressing high-order modes and gaining low-order modes, or mode. The holographic elements are made in the form of rectangular grooves that can be manufactured as binary features reproduced by methods of nanolithography or nanoimprinting.

Abstract: A multi-element diffraction grating is disclosed. The multi-element diffraction grating may be configured to diffract incident radiation with high dispersion using at least two holographic optical elements. The multi-element diffraction grating may include a first volume phase grating that is one of the holographic optical elements. The multi-element diffraction grating may also include at least one additional volume phase grating that is the second holographic optical element. The first volume phase grating and each of the additional volume phase gratings may be positioned relative to each other such that the radiation propagates through and is diffracted by the first volume phase grating and each of the additional volume phase gratings.

Abstract: Three-dimensional holographic elements are disclosed. Three-dimensional Bragg gratings recorded on bulks of optical material are included in the disclosure. Such elements may be manufactured by placing a three-dimensional bulk of optical material directly behind a recorded master hologram, directing a reference beam onto a master hologram such that a replica of the master hologram is recorded in the optical material. The replica may form the three-dimensional holographic element. The master hologram may be Bragg grating formed on a surface of a transparent substrate.

Abstract: Currently known holographic recording media and sensors have a number of disadvantages, for example, silver halide-based recording media is expensive to produce and unsuitable for use in certain sensor applications, and photopolymer-based recording media make it difficult to record multiple holographic images, thus, generally, rendering them unsuitable for use in sensors. Holographic recording media according to an embodiment of the present invention may comprise a polymer matrix and a chemical group that dimerizes by forming a cyclic bridge through photocycloaddition. These holographic recording media are cost-effective, allow recording of multiple holographic images, and enable production of sensors with controlled observable response to an external stimulus.

Abstract: A zoetrope configured for user interaction. The zoetrope includes an object support that pivotally supports a holographic disc or other projection element containing a plurality of images. A positioning mechanism rotates the holographic disc at a predetermined speed or positions the projection element in numerous positions. The disc or projection element is illuminated by an illumination source in such a manner as to selectively make the images contained therein be projected in a sequence that provides a projected object that may be animated in an interactive manner based on user input such as voice input. The zoetrope may read out holographic images in response to a user's voice input to project a 3D object that appears to be speaking the words or song input by the user such as by illuminating the disc once per revolution in a particular angular orientation associated with a desired one of the holographic images.

Abstract: To determine authenticity of a solid body simply and precisely, a reference area of a paper sheet which is genuine is optically read from two different directions, and the image is registered as a reference image. A check area of a paper sheet subjected to the authenticity determination, including the reference area and having a size larger than the reference area, is read from two different directions with a scanner, and data on a partial area having the same size as the reference area are extracted from each set of check data collected by the reading. For a set consisting of the reference image and the check image optically read from the same direction, the value of the correlation with the reference image is repetitively calculated by the normalized correlation method while the partial area is shifted within the check area. The maximum correlation value and the normalized score of the maximum correlation value are compared with respective thresholds to determine the authenticity of the paper sheet.

Abstract: An optics system is provided that is made up of a single diffractive optical element that performs beam collimating, beam splitting, and light blocking functions. The diffractive optical element is made up of a substrate having a first surface comprising an entrance facet and a second surface comprising an exit facet. The first surface comprising the entrance facet performs at least the functions of collimating the beam of light produced by the light source and of tilting the collimated beam in a particular direction. The second surface comprising the exit facet performs at least the functions of splitting the tilted collimated beam into at least two collimated light beams and of blocking unintended light (i.e., one or more mode order groups that are not intended to be used for imaging purposes). By performing all of these functions on different surfaces of a single substrate, an extremely compact optics system having very high optical efficiency and a very high signal-to-noise ratio is realized.

Abstract: A display for measured quantities can include a dial plaque with at least one set of indicia spaced around the plaque to indicate the measured quantities. An optical device can be mounted on a shaft within a perimeter of the dial plaque at a location surrounded by the indicia. The optical device can redirect an incident light beam onto the area of the set of indicia. A motor can turn the shaft to rotate the optical device through three-hundred-sixty degrees about an axis of rotation centered on the shaft. Apparatus can be provided for sensing the shaft rotating angular position. A light source can project a light beam on the optical device through the axis of rotation, such that a virtual pointer is generated.

Abstract: A dual layer holographic color filter and a transmissive liquid crystal display using the same. The dual layer holographic color filter includes a first hologram, which is provided between a light source and the liquid crystal display to spatially split white light from a substrate at the side of the light source, and a second hologram, which allows the split light to have the same direction as that of the light from the light source, to receive only light having a spectral bandwidth corresponding to colored cells of a color filter, so that the luminance of the liquid crystal display is enhanced. Light passing through the first hologram including hologram pieces is diffracted at different angles according to wavelengths. The second hologram recovers the traveling direction of the white light spatially split in the first hologram to an original direction of light from the light source.

Abstract: Embodiments of the present invention relate to holographically illuminated imaging devices including a holographic element for transforming an illumination beam into a focal array of light spots, a scanning mechanism for moving an object across one or more light spots in the focal array of light spots, and a light detector for detecting light associated with the focal array of light spots and generating light data associated with the received light.

Abstract: A holographic light guide plate has a transparent substrate and a plurality of diffraction patterns formed thereon. The diffraction patterns are arranged on one of a top surface and a bottom surface of the transparent substrate. The diffraction patterns diffract light incident on the transparent substrate. Each of the diffraction patterns has a continuously varying interval.

Abstract: A system and method for determining encoded information borne by transportation modalities. The system includes substrates carried by the modalities and an optical interrogation device capable of remotely acquiring the information and comparing it with a database of acceptable information incorporated into or proximal to the system. The encoded information is provided on the substrate in a matrix of zones exhibiting different optical properties. The matrix of zones and the associated properties constitute a code which is interrogated and read by the system.

Abstract: A complex objective lens composed of a hologram and an objective lens, capable of realizing stable and high-precision compatible reproducing/recording of a BD with a base thickness of about 0.1 mm for a blue light beam (wavelength ?1) and a DVD with a base thickness of about 0.6 mm for a red light beam (wavelength ?2). In an inner circumferential portion of the hologram, a grating is formed. The hologram transmits a blue light beam as 0th-order diffracted light without diffracting it, and disperses a red light beam passing through an inner circumferential portion as +1st-order diffracted light and allows it to be condensed by an objective lens. Because of this, the focal length of the red light beam becomes longer than that of the blue light beam, whereby a working distance is enlarged.

Abstract: An optical head apparatus including a holographic optical device which diffracts a light beam and includes a first diffraction region and a second diffraction region facing each other across a region dividing line passing through an optical axis of a light-collection optical system and extending in a radial direction of an optical disc, the first diffraction region having a grating pattern for generating diffracted light having a first wavefront and entering a first photoreception region and a second photoreception region, the second diffraction region having a grating pattern for generating diffracted light having a second wavefront and entering a third photoreception region and a fourth photoreception region, the first and second wavefronts having first and second coma aberrations in the radial direction of the optical disc, respectively, and the first and second coma aberrations having axes located off the optical axis.

Abstract: An apparatus for reading a hologram, in particular a computer-generated hologram, that includes a radiation source for irradiation of the hologram with a read beam composed of electromagnetic radiation, and an outlet opening for receiving an image that is produced from the hologram. The apparatus may allow both greater variability and greater convenience in use with a simple design. The apparatus further includes optics having at least two lenses in which a focal point of the first lens and a focal point of the second lens are each arranged essentially on one plane, and in which the hologram is arranged in front of the second lens as viewed along the beam direction.

Abstract: The proposed laser-beam system is a compact device of a hybrid or monolithic type, which is based on the use of digital planar holography (DPH) and is capable of coherently combining laser beams emitted from various laser sources. The hybrid DPH beam combiner is fabricated on a separate substrate and is optically coupled with a laser array, while the monolithic combiner is embedded into the laser array planar waveguide. In both configurations, the DPH combiner performs coherent combining and thus preserves a single transverse mode in combined laser beams at a common wavelength.

Abstract: A display system includes and image-guiding substrate with input and/or output structures configured to improve image quality.

Abstract: For displaying a color image by recombination of several single color images, parasitic noise like speckles due to scattering within the system, in particular when laser light is involved, with the invention a significant improvement with a low number of parts can be realized by use of a color wheel that comprises in radially divided zones refractive elements for redirecting light beams incoming at different impinging angles and redistributing elements, e.g. a hologram, that provide for a defined output beam in an optical axis. The sequence of the individual light processing zones on the color wheel are synchronized with respective laser sources. The invention combines the functionality of plural elements, reduces speckles and avoids losses.

Abstract: A method and system for establishing extended optical traps for commercial use. The method and system employs a diffractive optical element (DOE) to process a light beam wherein the DOE includes phase information and amplitude information to create the extended optical trap. Such extended traps can be line traps and can be further expanded to two and three dimensional configurations.

Abstract: Parallel coherent light from the laser 210 is irradiated through the light bending device 215 onto the hologram recording medium 220 having a hologram image of a scatter plate recorded, and a hologram reproduction real image 235 of the scatter plate is generated using the parallel light flux LL as illumination light for reproduction. The spatial light modulator 240 composed of a liquid crystal display, etc., is disposed so as to overlap on the position of the hologram reproduction real image 235, thereby obtaining a modulated image on a surface of the reproduction real image 235 of the scatter plate. The modulated image is projected onto the screen 260 by the projection optical system 250. The light bending device 215 is composed of a diffraction grating in which the pitch and direction of the grating lines are changed in terms of time, wherein the irradiation angle of the parallel light flux LL is changed in terms of time, and the illumination light beam scans on the screen 260.

Abstract: A security element, preferably for documents of value, which at least has one area with a diffraction structure, which under specific viewing conditions reconstructs a diffractive image. This area has subareas, which do not take part in the reconstruction of the diffractive image, and which represent a recognizable information. Essential is that the information represented by the subareas is recognizable mainly only under the viewing conditions, under which the diffractive image can be perceived.

Abstract: The present invention fabrication method and apparatus provides a method of creating holographic configurations in a specific pattern in glass panels using a laser that does not use chemicals or chemical solutions.

Abstract: A multicolor hologram (e.g., a two-color hologram) is replicated (copied) into a photosensitive layer by masking to produce a copy (replicate) of the hologram in a manner such that the copy is an accurate and true replication of the hologram (e.g., master hologram), and the copy is characterized to possess a high brightness level and color fidelity comparable to that of the multicolor hologram that was replicated. Both flood and scan modes can be employed in the replication.

Abstract: A method for manufacturing a hologram projection screen includes the steps of: 1) recording hologram lens information on a photoresist plate; 2) metalizing the photoresist plate that has been exposed, to produce a master nickel plate of a hologram lens array through electroforming and joining; and 3) using the master nickel plate to emboss thermoplastic material, to obtain a screen body, on which the information of the hologram lens array is arranged. The hologram projection screen manufactured by this method can provide a variety of display contents.

Abstract: A multiple function optical image detecting structure includes a shell body, a tracing ball, an optical base, a circuit board, a light-emitting element, and an image sensor. The shell body receives the tracing ball. The optical base has a slanted spectroscope that faces part of the spherical surface of the tracing ball and a lens element located on one side of the spectroscope. The light-emitting element and the image sensor are electrically connected with the circuit board. The light-emitting element faces towards the spectroscope and the image sensor faces towards the lens element. The light axial of the projected light generated from the light-emitting element is reflected/transmitted to the surface of the tracing ball via the spectroscope. Thereby, the light is uniformly projected on the tracing ball and the image sensor obtains the image on the lens element to calculate a displacement.

Abstract: The image displaying apparatus includes an image production apparatus, a first light conduction section and a second light conduction section. The first light conduction section includes a first light conduction plate which propagates part of incident light thereto by total reflection in the inside thereof and emits the propagated light, and a reflection type volume hologram diffraction grating disposed on the first light conduction plate. The second light conduction section includes a second light conduction plate, a first deflection section and a second deflection section.

Abstract: An exposure apparatus according to an exemplary embodiment of the invention includes a substrate in which plural light-emitting devices are arrayed one-dimensionally or two-dimensionally; and a hologram recording layer that is disposed on the substrate, plural holograms being recorded in the hologram recording layer by holographic interference between a first beam and a second beam such that a predetermined number of beam spots are disposed in the hologram recording layer in a predetermined array direction according to a portion of light-emitting devices, the portion of light-emitting devices being selected as emitters from the plural light-emitting devices, the beam spot being formed by a light beam of the second beam, the first beam passing through an optical path of diffusion light that passes through the emitter, the second beam passing through an optical path of convergent light that converges at a predetermined distance outside the optical path of the first beam.

Abstract: The invention relates to techniques for speckle reduction in holographic optical systems, in particular holographic image display systems. We describe a holographic image display system for displaying an image holographically on a display surface, the system including: a spatial light modulator (SLM) to display a hologram; a light source to illuminate said displayed hologram; projection optics to project light from said illuminated displayed hologram onto said display surface to form a holographically generated two-dimensional image, said projection optics being configured to form, at an intermediate image surface, an intermediate two-dimensional image corresponding to said holographically generated image; a diffuser located at said intermediate image surface; and an actuator mechanically coupled to said diffuser to, in operation, move said diffuser to randomise phases over pixels of said intermediate image to reduce speckle in an image displayed by the system.

Abstract: The present invention provides a hologram which forms a light intensity distribution on a predetermined plane by using an incident light. The hologram includes a plurality of cells configured to control both a phase of a first polarized light component of the incident light and a phase of a second polarized light component. The plurality of cells are designed to form a portion in an overlap region in which a first light intensity distribution region formed on the predetermined plane by the first polarized light component and a second light intensity distribution region formed on the predetermined plane by the second polarized light component are superposed on each other. The phase of the first polarized light component is diffused in the portion formed in the overlap region.

Abstract: A spectral filter comprises a planar optical waveguide having at least one set of diffractive elements. The waveguide confines in one transverse dimension an optical signal propagating in two other dimensions therein. The waveguide supports multiple transverse modes. Each diffractive element set routes, between input and output ports, a diffracted portion of the optical signal propagating in the planar waveguide and diffracted by the diffractive elements. The diffracted portion of the optical signal reaches the output port as a superposition of multiple transverse modes. A multimode optical source may launch the optical signal into the planar waveguide, through the corresponding input optical port, as a superposition of multiple transverse modes. A multimode output waveguide may receive, through the output port, the diffracted portion of the optical signal. Multiple diffractive element sets may route corresponding diffracted portions of optical signal between one or more corresponding input and output ports.