Abstract: Transmission and reflection type holograms may be formed utilizing a novel polymer-dispersed liquid crystal (PDLC) material and its unique switching characteristics to form optical elements. Applications for these switchable holograms include communications switches and switchable transmission, and reflection red, green, and blue lenses. The PDLC material of the present invention offers all of the features of holographic photopolymers with the added advantage that the hologram can be switched on and off with the application of an electric field. The material is a mixture of a polymerizable monomer and liquid crystal, along with other ingredients, including a photoinitiator dye. Upon irradiation, the liquid crystal separates as a distinct phase of nanometer-size droplets aligned in periodic channels forming the hologram. The material is called a holographic polymer-dispersed liquid crystal (H-PDLC).

Abstract: Method and apparatus are contemplated for receiving from an input, an optical signal in a volume hologram comprising a transfer function that may comprise temporal or spectral information, and spatial transformation information; diffracting the optical signal; and transmitting the diffracted optical signal to an output. A plurality of inputs and outputs may be coupled to the volume hologram. The transformation may be a linear superposition of transforms, with each transform acting on an input signal or on a component of an input signal. Each transform may act to focus one or more input signals to one or more output ports. A volume hologram may be made by various techniques, and from various materials. A transform function may be calculated by simulating the collision of a design input signal with a design output signal.

Abstract: Systems and methods for making a self-aligning optical system are provided, Briefly described, in architecture, one such system for making an optical system, among others, can be implemented as follows. The system includes a grating substrate supporting a holographically-formed diffraction grating and an array mount for defining relative locations of point sources of light. The array mount contains recording points that define locations of point sources of recording light used to illuminate the grating substrate during fabrication of the holographically-formed diffraction grating and use points that define locations of light apertures used in operation of the holographically-formed diffraction grating. Other systems and methods are also provided.

Abstract: A Schottky barrier photodetector comprises a waveguide structure formed by a thin strip of material having a relatively high free charge carrier density, for example a conductor or certain classes of highly-doped semiconductor, surrounded by material having a relatively low free charge carrier density, the material on at least one side of the strip comprising a semiconductor, the strip having finite width and thickness with dimensions such that optical radiation couples to the strip and propagates along the length of the strip as a plasmon-polariton wave, light for detection being coupled to one end of the strip to propagate along the strip as said plasmon-polariton wave, ohmic contact means applied to the semiconductor material and at least one electrode means connected to the strip for applying bias to the Schottky barrier and extracting a photodetector current corresponding to the light applied to the photodetector.

Abstract: A display system includes a waveguide optical panel having an inlet face and an opposite outlet face. A projector cooperates with a digital imaging device, e.g. a digital micromirror imaging device, for projecting an image through the panel for display on the outlet face. The imaging device includes an array of mirrors tiltable between opposite display and divert positions. The display positions reflect an image light beam from the projector through the panel for display on the outlet face. The divert positions divert the image light beam away from the panel, and are additionally used for reflecting a probe light beam through the panel toward the outlet face. Covering a spot on the panel, e.g. with a finger, reflects the probe light beam back through the panel toward the inlet face for detection thereat and providing interactive capability.

Abstract: An optic switch for cross-connecting input light signals incoming from inlet fiber cables to outlet fiber cables is disclosed that makes use of a holographic filter (5) having a series of preformed different speckle patterns, each in the form of a hologram (H1, H2, . . . ). Associated with input light signals guided past respective inlet passages (4in) of a multimode waveguide (4), different speckle patterns are formed by applying different control voltages across respective electrode pairs (10, 10a) provided thereon. These speckle patterns past a single outlet passage (4out) of the multimode waveguide (4) into which the inlet passages (4in) converge are joined together and enter the holographic filter (5) in which an input light signal is selectively switched, addressed and cross-connected to an outlet waveguide (2) through a region thereof where a formed speckle pattern coincides with a preformed speckle pattern. The multi mode waveguides (4) is formed in, e.g., a LiNbO3 photorefractive substrate (3).

Abstract: Method and apparatus are disclosed for optical packet decoding, waveform generation and wavelength multiplexing/demultiplexing using a programmed holographic structure. A configurable programmed holographic structure is disclosed. A configurable programmed holographic structure may be dynamically re-configured through the application of control mechanisms which alter operative holographic structures.

Abstract: The invention provides an optical switcing device, including a substrate having at least one polarization-selective multiplexing grating; at least one polarization-selective demultiplexing grating, and a polarization rotation element acting as a dynamic ½ ? plate, optically interposed between the optical path of said multiplexing grating and said demultiplexing grating. The invention also provides a method for producing an holographic plate having a plurality of holographic elements.

Abstract: The present invention is a method and apparatus for a rotating, tunable, holographic drop filter connected to a fiber optic source. The filter uses a quasi phase-conjugate optical system for a drop-channel fiber coupling and WDM channels which are introduced to the system. The light from these channels is collimated and passed through a volume phase holographic material so that only one WDM channel is diffracted and the rest pass through the holographic material unaffected. A quasi phase-conjugate diffracted beam is generated by the optical system to reflect the diffracted channel back towards the holographic material. The reflected light is Bragg matched to the holographic material so that it is re-diffracted along a path identical to the original incident light beam. A free-space circulator may be used to direct the diffracted beam to a fiber optic collimator, which is different from the fiber optic collimator of the incident light beam.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: A holographic ROM system includes an alignment apparatus for aligning a holographic medium for storing data and a mask with patterns of the data. The alignment apparatus has a beam irradiating unit for irradiating a light beam to alignment marks of the holographic medium and the mask; an alignment mechanism for moving at least one of the holographic medium and the mask in response to a control signal; a photo detecting unit for detecting the beam passing through the alignment marks of the holographic medium and the mask while the holographic medium and/or the mask being moved; and a control unit for generating the control signal, the control unit controlling the alignment mechanism based on intensity of the beam detected by the photo detecting unit.

Abstract: Method and apparatus are disclosed for optical packet decoding, waveform generation and wavelength multiplexing/demultiplexing using a programmed holographic structure. A configurable programmed holographic structure is disclosed. A configurable programmed holographic structure may be dynamically re-configured through the application of control mechanisms which alter operative holographic structures.

Abstract: A method for manufacturing a FBG having improved performances and an annealing-trimming apparatus for making the same are provided. The trimming and the annealing steps are advantageously combined into a single process in order to efficiently fabricate complex FBG filters with improved performance. The method comprises the steps of UV-writing a FBG in an optical fiber prior to annealing-trimming characteristics of the FBG by performing the sub-steps of monitoring characteristic data of the FBG while generating a controlled complex temperature profile along the FBG with a heating means according to the characteristic data for providing an accurate controlled annealing process of the FBG, thereby providing an accurate trimming thereof.

Abstract: A fiber Bragg grating may be written at an arbitrary wavelength without extensive recalibration or reconfiguration of the writing equipment in some embodiments. A pair of writing beams may be used to expose the fiber. The crossing angles of the writing beams may be adjusted.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An object beam divided by a light dividing means 12 is caused to enter a photo-refractive polymer layer 6 through an optical fiber 23. On the other hand, a reference beam divided by the light dividing means 12 is irradiated on the photo-refractive polymer layer 6 through a lens 13 from the opposite side. In this manner, the object beam is superimposed on the reference beam in the photo-refractive polymer layer 6 to provide an interference fringe or pattern. Since a photo-refractive polymer has a specific characteristic whereby the refractive index changes according to the intensity of irradiation light and the change is fixed after the irradiation light is stopped, a diffraction grating 5 corresponding to the interference fringe is recorded on the photo-refractive polymer layer 6. This diffraction grating 5 exhibits a specific characteristic whereby the object beam emitted from the optical fiber 23 is emitted in the direction of the reference beam.

Abstract: An optical device for enlarging an eye box, the optical device comprising: (a) a first optical expander being carried by, or formed in, a first light-transmissive substrate engaging a first plane; and (b) a second optical expander being carried by, or formed in, a second light-transmissive substrate engaging a second plane being spaced apart from the first plane. The first and the second optical expanders designed and configured such that light passing through the first optical expander is expanded in a first dimension, enters the second light-transmissive substrate through the second optical expander, and exits from the second light-transmissive substrate, expanded in a second dimension, hence enlarging an eye box of the optical device in both the first and the second dimensions.

Abstract: A method for optical coupling comprises: providing a holographic recording media fixed relative to at least two optical elements; creating a hologram by transmitting light from each of the optical elements to the recording media; and transmitting light from a sending element of the optical elements through the recording media to a receiving element of the optical elements. Other variations include a system comprising at least two optical elements situated on one side of the recording media and an optical detector situated on an opposite side for detecting light transmitted through the opposite side; and a system comprising at least three optical elements situated on one side of the recording media, a beam splitter, and optical pump/control beams configured for transmitting an optical pump/control beam to the beam splitter and the opposite side so as to control transmission of an optical signal.

Abstract: A grating interference device with adjustable resolution has high stability and precision adjustment functions. The invention has two reflectors and a beam splitter. One of the reflector is installed on a rotating axis along with an optic fiber or a platform of planar waveguide. Through the rotating axis, this reflector and the platform are maintained at a fixed relative angle and rotate with respect to the other reflector and the beam splitter. The period of the interference grating is controlled by the angle change, producing a grating with a micrometer-order period on the optic fiber or the planar waveguide.

Abstract: There is disclosed a method for the holographic recording of data, wherein a hologram containing the date is recorded in a waveguide layer (3). The holograms are formed in a layer structure containing multiple waveguide layers (3). Coupling means (12) are provided for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure. The invention also relates to an arrangement for holographic recording of data, comprising a data storage medium with a waveguide holographic storage layer, and an optical system for writing and reading the holograms. The optical system comprises means for imaging an object beam (5) and a reference beam (11) on the storage medium. The arrangement comprises multiple waveguide holographic storage layers (3) in the storage medium, and means for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure.

Abstract: A polarized light-emitting waveguide for use in an edge-lit lighting arrangement has polarization-selective outcoupling structure including at least a volume hologram for selectively diffracting waveguided light towards the exit surface of the waveguide with high contrast and efficiency. The light emitted by the waveguide is selectively emitted to one side thereof, highly polarized, highly collimated and may be homogeneously distributed across the exit surface. Also, light emission may be normal or near-normal to the exit surface. If combined with light recycling means the contrast, brightness and/or efficiency of the edge-lit illumination arrangement may be further increased.

Abstract: An ultrathin mesh optical panel and a method of use and making are disclosed. One embodiment of the optical panel includes a plurality of optical waveguides, wherein each optical waveguide is formed of a mesh material surrounding an optically clear core. The optical panel further includes a light generator. Each optical waveguide internally reflects the light incoming at the inlet of the waveguide to the outlet of the waveguide. The optical panel may optionally include a light redirecting coupling layer and/or a diffuser. An alternate embodiment of the ultrathin optical panel includes a plurality of optical waveguides, wherein the mesh material serves as the light transmissive material. A method of making and using is applicable to both major embodiments. A modification of either embodiment is disclosed wherein the optical waveguide is aligned to be non-perpendicular to the panel face.

Abstract: A method and system of projecting light on a planar surface to produce an image for tracing is disclosed. The system includes a projector that has a light source and a signal conditioner that is operably connected to the projector. A computer is operably connected to the signal conditioner. A scanner is connected to the projector. A test pattern from the computer is projected from the projector through the scanners to visually align an image to a sector on a work surface. A grid is operably aligned with the work surface. A geometric pattern from the computer is then projected by the projector on the planar work surface for tracing. The method comprises the steps of creating a pattern, tracing lines along the pattern on the planar work surface, cutting the pattern along the traced lines, discarding pieces of the planar surface outside the pattern, and placing edging along an outer edge of the pattern.

Abstract: An apparatus for a free space optical communication system includes an element having a front surface and a back surface. A holographic optical element (HOE) is disposed to receive a light signal from the free space optical communication system, and to angularly direct the light signal, having a certain wavelength, towards one of the surfaces of the element to allow the light signal to propagate between the front and back surfaces of the element via total internal reflection. The internally reflected light signal eventually converges and is received at an optical detector circuit. At the same time, light having other wavelengths, including visible background light, passes through the HOE, thereby giving the apparatus an appearance of being transparent and unobtrusive.

Abstract: The present invention provides an optoelectronic device, a method of manufacture thereof and an integrated optoelectronic system incorporating the same. The optoelectronic device may be a tunable laser that includes a capacitor located over one of the first outer surface or the second outer surface. The outer metal layers of the tunable laser can be used to form a first electrode of the laser, after which a dielectric layer and a second electrode are deposited and patterned to form the laser having a capacitor incorporated thereon.

Abstract: A method and device provide efficient wavelength division multiplexing/demultiplexing (WDM) including reduced signal distortion, higher wavelength selectivity, increased light efficiency, reduced cross-talk, and easier integration with other planar devices, and lower cost manufacturing. The method and device include a planar holographic multiplexer/demultiplexer having a planar waveguide, the planar waveguide including a holographic element that separates and combines pre-determined (pre-selected) light wavelengths. The holographic element includes a plurality of holograms that reflect pre-determined light wavelengths from an incoming optical beam to a plurality of different focal points, each pre-determined wavelength representing the center wavelength of a distinct channel. Advantageously, a plurality of superposed holograms may be formed by a plurality of structures, each hologram reflecting a distinct center wavelength to represent a distinct channel to provide discrete disperstion.

Abstract: An apparatus and method are provided for communicating optical signals between components attached to an optical backplane bus. Each component has a respective active coupler to receive and transmit optical signals through a waveguiding plate. Multiplexed polymeric holograms may be used to couple or direct optical signals between the components and the waveguiding plate. Optical signals received from any component may be rebroadcast to all other components by a distributor and its active coupler using a doubly multiplexed hologram. The distributor and its active coupler may be located proximate a midpoint of the waveguiding plate.

Abstract: A laminated optical medium for read-only information recording has ultra-high memory capacity and reliably extracts desired information from laminated memories. Methods for low-cost mass production of laminated read-only medium are demonstrated. The optical medium is a lamination of planar type waveguides made of polymeric materials, in which each waveguide has information recorded as periodic scattering factor to generate scattered light by injection of input light into a waveguide layer. Therefore, read-only information recording medium of ultra-high memory capacity, equivalent to the memory capacity achievable by volume holography, can be produced by using a low-cost planar holographic technique. The laminated medium is simple and energy conserving, because it does not require rotation mechanisms for reproduction of music and video holographic recordings.

Abstract: There is disclosed a method for the holographic recording of data, wherein a hologram containing the date is recorded in a waveguide layer (3). The holograms are formed in a layer structure containing multiple waveguide layers (3). Coupling means (12) are provided for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure. The invention also relates to an arrangement for holographic recording of data, comprising a data storage medium with a waveguide holographic storage layer, and an optical system for writing and reading the holograms. The optical system comprises means for imaging an object beam (5) and a reference beam (11) on the storage medium. The arrangement comprises multiple waveguide holographic storage layers (3) in the storage medium, and means for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure.

Abstract: A method of writing an extended grating structure in a photosensitive waveguide comprising the steps of utilising at least two overlapping beams of light to form an interference pattern, moving the waveguide through said overlapping beams, simultaneously controlling a relative phase delay between the beams utilising a phase modulator, thereby controlling the positions of maxima within said interference pattern to move at approximately the same velocity as the photosensitive waveguide, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and modifying the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilised to vary a period of the written grating structure in the photosensitive waveguide.

Abstract: Method and apparatus are disclosed for optical packet decoding, waveform generation and wavelength multiplexing/demultiplexing using a programmed holographic structure. A configurable programmed holographic structure is disclosed. A configurable programmed holographic structure may be dynamically re-configured through the application of control mechanisms which alter operative holographic structures.

Abstract: The invention provides a holographic optical device, including a light-transmissive substrate; a first holographic optical element carried by the substrate; at least one second holographic optical element carried by the substrate laterally of the first holographic optical element, and at least one third holographic optical element carried by the substrate laterally displaced from the first and second holographic optical elements; wherein the center of at least one of the first, second or third holographic optical elements is located outside a single, straight line.

Abstract: A method of writing a Bragg grating in a photosensitive optical waveguide (40) is disclosed comprising utilizing a single coherent beam of light (31) and a diffraction grating (32) to create two coherent working beams (33, 38) of light; positioning a plurality of reflective elements (35, 37) on each side of said waveguide; propagating the two working beams around said plurality of reflective elements, each of the beams being reflected by each of the reflective elements, so that the beams interfere at an initial predetermined position (45); and rotating at least one of the reflective elements on each side of the waveguide to simultaneously independently control the period of the interference pattern and position of the interference pattern in accordance with predetermined requirements so as to produce the grating structure in the photosensitive waveguide.

Abstract: A phase mask (15) for modulating a collimated light beam passing therethrough, the light beam being diffracted to photoinduce a refractive index profile in a photosensitive optical medium, the phase mask (15) comprises a substrate (17) having an outer surface provided with a plurality of parallel grating corrugations (19). The grating corrugations (19) have a non-uniform relief depth across the outer surface for photoinducing a non-uniform refractive index profile in the photosensitive optical medium. The non-uniform relief depth is defined by a variable thin film layer (21) of variable thickness overlaying the substrate (17). The grating corrugations (19) can either be etched into the variable thin film layer (21) itself or be etched into the substrate (17), with the variable this film layer (21) being deposited on it after etching. Methods to make such phase masks are also provided.

Abstract: A method and apparatus for interference lithography utilize a fiber having a cladding region with axially formed holes surrounding a core region. The fiber emits an optical signal to perform interference lithography. A number of alternative variations in the size and arrangement of axially formed holes produces fibers having characteristics particularly adapted for receiving, communicating, and emitting optical signals for interference lithography.

Abstract: A holographic medium comprising an optical waveguide including at least one core layer positioned between portions having a lower refractive index; a diffraction grating layer formed at a boundary between the core layer and the above portions or in the core layer; and a storage layer outside the optical waveguide. An optical waveguide having the above structure in which the diffraction efficiency of the diffraction grating layer has a specific distribution is useful. In multiple-angle storage, a reference beam is emitted from an end face of a core layer or from the upper or lower side of the medium and a photodetector may be used, so as to control the incident angle. The reference beam and/or the optical waveguide is moved so that the reference beam couples only with a specific diffraction grating layer. The object beam may be focused onto a small target area of the storage layer.

Abstract: A method and device provide efficient wavelength division multiplexing/demultiplexing (WDM) including reduced signal distortion, higher wavelength selectivity, increased light efficiency, reduced cross-talk, and easier integration with other planar devices, and lower cost manufacturing. The method and device include a planar holographic multiplexer/demultiplexer having a planar waveguide, the planar waveguide including a holographic element that separates and combines pre-determined (pre-selected) light wavelengths. The holographic element includes a plurality of holograms that reflect predetermined light wavelengths from an incoming optical beam to a plurality of different focal points, each pre-determined wavelength representing the center wavelength of a distinct channel. Advantageously, a plurality of superposed holograms may be formed by a plurality of structures, each hologram reflecting a distinct center wavelength to represent a distinct channel to provide discrete disperstion.

Abstract: A holographic optical element (HOE) device useable for an optical receiver system has a first element having first and second surfaces, with the first surface being positionable to face incident light rays. The incident light rays can comprise laser light having data modulated thereon. An emulsion material is disposed over the second surface of the first element and has a recorded interference pattern that diffracts the incident light rays that pass through the first element. A second element overlies the emulsion material and is structured to pass resulting light rays derived from the incident light rays and diffracted from the recorded interference pattern. A plurality of reflective elements are positioned adjacent to the first and second elements. The reflective elements fold the resulting light rays within the second element, thereby allowing a reduction in separation length between the emulsion material and receiver electronics.

Abstract: A volume-phase optical grating, preferably supported between substrates and prisms, uses large-angle input and output light beams to provide a very high degree of dispersion and improved separation of closely spaced wavelength channels. The average refractive index of the grating medium is also less than that of the supporting substrates and prisms, thereby providing improved uniformity and reduced sensitivity to the state of light polarization. The device therefore finds utility as a wavelength multiplexer, demultiplexer or optical spectrum analyzer in fields such as optical communications and optical signal processing. The grating itself may be constructed by conventional interferometric or holographic techniques, and may be a reflection or transmission device. In a system configuration, optical fibers may be used to carry the multiplexed or demultiplexed optical signals. Optoelectric detectors may also be used to detect different wavelengths and convert the optical signals into electrical counterparts.

Abstract: A device and method for recording holographic gratings by the use of a single illuminating beam, two diffraction gratings, light detectors and a slit-scanning system. The beam illuminates two slits that then define two beams that are incident on the gratings. One diffracted order from one beam and one diffracted order from the other beam then interfere on a recording plane to produce sinusoidal variations of intensity. The interfering region may instantaneously be limited by a third slit. Also, another order of diffraction from one beam may be directed toward its own light detector and so is another order of diffraction from the other beam. These two detectors allow real time monitoring of the light intensity of each beam. By moving the slits in a direction parallel to the recording plane, an area larger than the slits' width can be exposed by the interfering pattern.

Abstract: The present invention is a method and apparatus for a rotating, tunable, holographic drop filter connected to a fiber optic source. The filter uses a quasi phase-conjugate optical system for a drop-channel fiber coupling and WDM channels which are introduced to the system. The light from these channels is collimated and passed through a volume phase holographic material so that only one WDM channel is diffracted and the rest pass through the holographic material unaffected. A quasi phase-conjugate diffracted beam is generated by the optical system to reflect the diffracted channel back towards the holographic material. The reflected light is Bragg matched to the holographic material so that it is re-diffracted along a path identical to the original incident light beam. A free-space circulator may be used to direct the diffracted beam to a fiber optic collimator, which is different from the fiber optic collimator of the incident light beam.

Abstract: A method and apparatus is disclosed for creating a structure, such as a grating (45) in a photosensitive material (40). The method and apparatus relies upon creating at least two coherent beams of light (33, 38) and reflecting them, in a counter propagating manner, around a series of reflective elements (35, 37) along substantially equivalent paths so that the coherent beams interfere at a structure staging area (45). The structure staging area can then be utilized to create grating structures or the like having improved qualities.

Abstract: A holographic light focusing device is disclosed. The device generally comprises an elongate member having an input end and an output end, a light source disposed at the input end, and a light guide extending along the elongate member and operable to guide a light beam emitted from the light source to the output end of the elongate member. The device further comprises a focusing system disposed at the output end of the elongate member. The focusing system includes a plurality of holographic optical elements switchable between an active state wherein light from the light source is diffracted by the element to focus the light and a passive state wherein the light is not substantially diffracted by the device. Each of the holographic elements is configured to focus the light at a different distance relative the output end when in its active state.

Abstract: A holographic universal display according to the present invention uses reflective lighting for a liquid-crystal panel. T he system comprises at least two waveguide holograms in a matched configuration that redirects incident light beams as diffracted beams so that the beams passing out of the display are targeted towards the viewer. That is to say, light beams that are incident to the display at large angles, over a wide range, with respect to normal are redirected into a set, narrow range of angles close to the required angle for optimal viewing. The required angle for optimal viewing is nominally perpendicular to the plane of the display (i.e., normal), but is optionally selectable (by design of the holograms) to be an angle varies from the strict perpendicular.

Abstract: Laser diodes are formed with an outcoupling grating between two separate distributed Bragg reflectors. The devices have gain regions located between the reflector gratings for pumping the active region. The outcoupling grating couples light out of the waveguide normal to the surface if the grating spacings are equal to an integer number of wavelengths of the light within the cavity. If the gratings are not such an integer number, the light is coupled out of the cavity off the normal.

Abstract: A method and apparatus particularly useful for telecommunications applications, such as switching (Add/Drop), multiplexing and demultiplexing, is disclosed. The method commences by directing a source of input optical signal(s) (10) onto a movable diffractive optical element or MDOE. Each of the optical signals is associated with a particular wavelength. Next, one or more output stations are supplied. Finally, the MDOE generates and distributes output optical signals among the output station(s). The corresponding system for treating the optical signals from a source thereof includes a source carrying two or more input optical signals, each of the signals being associated with a particular wavelength. Also included is a movable diffractive optical element positioned to intercept the source optical signals for producing and distributing one or more diffracted output optical signals. Finally, one or more output stations are positioned to receive the diffracted optical signal(s) from the MDOE.

Abstract: An information display device provided with a prism having at least two reflecting surfaces arranged in facing each other and a hologram surface formed of a reflection-type hologram. And at least one of the two reflecting surfaces is a light-beam-selective surface that selectively transmits or reflects light in accordance with its incident angle. An image light emitted from an image display means enters the prism, and is reflected between the reflecting surfaces, and then is diffractively reflected on the hologram surface, and, after being transmitted through the light-beam-selective surface, is directed to an observer's pupil.

Abstract: The purpose is to provide an illumination device for constructing a compact, light weight and inexpensive display device. The illumination device is provided with a light source for emitting light, and a holographic optical element for deflecting entering light to form light to illuminate a rectangular region, wherein the holographic optical element is arranged in contact with either the top or the bottom surface of a glass plate, and light emitted from the light source enters the glass plate through a side surface of the glass plate and is directed to the holographic optical element, such that the principal rays of the light enter the holographic optical element approximately perpendicular relative to one diagonal of the rectangular region.