Abstract: A device for recording a refractive index pattern in a photosensitive optical fiber includes a rotary disc formed with a phase mask in a circular pattern, which is rotated by an axis. The phase mask is illuminated with laser light in a region so that a moving interference pattern is formed. The optical fiber is moved along a path in synchronism with the moving interference pattern so that the pattern becomes recorded in the fiber. The pattern can be formed continuously over long fiber lengths, e.g., of the order of one meter.

Abstract: A compact, preferably monolithic optical element converts an incident beam of light into a dispersed exit beam. A transmissive optical grating is supported between two reflective surfaces such that a beam is reflected to pass through the same grating at least twice to form the exit beam. In the preferred embodiment the grating is a volume hologram cemented between two optically transmissive substrates which include outwardly oriented surfaces that are parallel to one another and to the grating, and the internal reflections occur at these surfaces. Mirrors may also be used. A preferred method of grating formation is also disclosed.

Abstract: An apparatus and method are disclosed for replicating a hologram. The apparatus comprises an assembly operable to position a hologram in proximity to holographic recording material. The apparatus further comprises a beam steering unit operable to direct a beam at component portions of the hologram to replicate the component portions onto a holographic recording material. The beam steering unit is further operable to enable independently variable angles of incidence at which the beam strikes each component portion.

Abstract: A holographic resonant system includes a plurality of volume phase holograms superimposed on a single layer of photosensitive film. The volume phase holograms are oriented with respect to one another such that a first volume phase hologram selects an incoming light beam incident upon a surface of the holographic resonant system having a wavelength &lgr;playback and an angle of incidence &thgr;in and internally diffracts the incoming light beam to a second volume phase hologram. The second volume phase hologram then accepts the resulting diffracted light beam from the first volume phase hologram and diffracts the light beam to form an image reflected from the surface of the holographic resonant system at wavelength &lgr;playback and an angle &thgr;out. The result is a holographic resonant system that only permits light beams from a predetermined direction to illuminate the system, thereby reducing the effect of ambient light upon the system and thus increasing the contrast ratio of the image.

Abstract: A planar optical correlator including at least first and second optical substrates (30, 32), through which light propagates by means of total internal reflection, at least first and second holographic lenses (20, 22) on the first optical substrate and optical third and fourth holographic lenses (24, 26) on the second optical substrate, each of the first and second and third and fourth holographic lenses performing a Fourier transformation on the input light to their respective optical substrates, the substrates positioned such that the second and third holographic lenses at least partially face each other. A filter (36) is positioned between the second and third holographic lenses.

Abstract: A holographic stereogram printing apparatus that is able to formulae a holographic stereogram superior in light utilization efficiency and in picture uniformity. The holographic stereogram printing apparatus causes the laser light from a laser light source 31 to fall on a picture display device 41 to illuminate the light transmitted through the display device 41 as object light on a holographic recording medium 30. The holographic stereogram printing apparatus also causes part of the laser light prior to being transmitted through the display device 41 to be illuminated as reference light on the holographic recording medium 30 to form the element holograms sequentially on the holographic recording medium 30. In the holographic stereogram printing apparatus, a light integrator 63 for uniforming the intensity of light incident on the display device 41 is provided on the optical path of the laser light proceeding towards the display device 41.

Abstract: A holographic lithography tool (110) for generating a light interference pattern used to expose a photosensitive medium (119) employs a refracting prism (121) in the optical path between divergent illuminating beams (127a, 127b). The prism is optically coupled to the photosensitive medium via an index matching fluid (123). By increasing the incident beam angle and the index of refraction, the prism reduces the size of features recorded in the photosensitive material. The divergent illuminating beams are generated by a beam delivery system which preferably employs easily adjustable fiber optic cables (176, 184). Use of the prism coupling technique facilitates use of fiber-optic-compatible wavelengths in the blue region of the spectrum in a variety of applications, such a distributed feedback grating fabrication.

Abstract: The invention comprises a spatial filter and a method of spatially filtering a laser beam, particularly a high power laser beam. The inventive spatial filter and method of use is especially suited for use in an optical system for writing index gratings in optical waveguides. The invention provides a method of writing gratings in optical waveguide fiber that results in improved grating performance.

Abstract: A holographic optical device includes a light transmissive substrate carrying first and second laternally separated holographic optical elements. The first holographic optical element diffracts incident light into the substrate where it is trapped by internal reflection so that light impinges more than once at different angles at different locations on at least one of the first and second holographic optical elements with a significantly higher efficiency for one angle of incidence. The second holographic optical element diffracts light out of the substrate. The second holographic optical element may be a display hologram for displaying a three-dimensional image.

Abstract: A dichroic or trichromatic transparent display apparatus through which a background view is seen comprises a transparent substrate, a hologram formed on a rear face of the transparent substrate, a dispersion liquid crystal device disposed in front of a front face of the transparent substrate, a light source disposed for facing a side face of the transparent substrate and a transparent layer at least partially provided between the transparent substrate and the hologram. The refractive index of the transparent layer is smaller than that of the transparent substrate. A first light emitted from the light source and having a first wavelength is totally reflected by the boundary face between the transparent substrate and the transparent layer so that the first light moves to and is diffracted by a first region of the hologram where the transparent layer is not provided. A second light having a second wavelength is diffracted by a second region of the hologram where the transparent layer is provided.

Abstract: Boron containing glasses are sensitive to radiation in the band 225-275 nm and therefore, B.sub.2 O.sub.3 glasses are particularly adapted to receive refractive index modulation, e.g., to make reflection gratings. Glasses containing SiO.sub.2 and B.sub.2 O.sub.3 are particularly suitable when the grating is to be localized in the cladding of a fibre. Glasses containing SiO.sub.2, GeO.sub.2 and B.sub.2 O.sub.3 are suitable when the grating is in the path region of a waveguide, e.g., in the core of a fibre.

Abstract: It has been demonstrated that B containing glasses are sensitive to radiation in the band 225-275 nm and, therefore, B.sub.2 O.sub.3 glasses are particularly adapted to receive refractive index modulation, e.g., to make reflection gratings. Glasses containing SiO.sub.2 and B.sub.2 O.sub.3 are particularly suitable when the grating is to be localized in the cladding of a fiber. Glasses containing SiO.sub.2, GeO.sub.2, and B.sub.2 O.sub.3 are suitable when the grating is in the path region of a waveguide, e.g., in the core of a fiber.

Abstract: A projection-type displaying apparatus is disclosed. The apparatus has a coupling prism, a glass substrate joined to the coupling prism and a liquid crystal display panel containing pixel electrodes. A refractive index of the coupling prism is greater than a refractive index of the glass substrate. The apparatus also has a transmission-type holographic color filter provided between the glass substrate and liquid crystal display panel. Light beams enter the apparatus through the plane of incidence of the coupling prism and go through the glass substrate. The light beams are then focused onto the pixel electrodes by the holographic color filter. The focused light beams are modulated by the pixel electrodes and exit the apparatus as projection light beams.

Abstract: A volume holographic data storage(VHDS) system incorporates therein a tapered optical fiber for generating a speckle beam pattern from the tapered optical fiber for increasing the amount of holograms to be stored into a photorefractive crystal. The VHDS system includes a light source for generating a coherent light beam, a beam splitter for splitting the coherent light beam into a reference and a signal beams, a storage medium for storing the multiple holograms thereinto, a mirror for directing the signal beam to the storage medium, a coupler for coupling the reference beam to the tapered optical fiber, wherein one end of the tapered optical fiber has a tapered structure to give perturbation in the form of a speckle pattern to the reference beam from the tapered optical fiber and the reference beam containing the speckle pattern travels to the storage medium after being transmitted through the tapered structure, thereby the speckle pattern reference beam interfering with the signal beam in the storage medium.

Abstract: A multi-line continuous wideband tunable laser (1) utilizes a symmetric or asymmetric grating (5) and a plurality of optical fibers (3), each of which forms a part of a respective laser cavity optical axis. By simultaneously altering both the periodicity of the intersections of the grating (5) with the plurality of optical axes established by the plurality of optical fibers (3) and the effective cavity length of each laser (1), a single-line spectral output is achieved at any desired point in the operating band.

Abstract: A light-emitting assembly defining a pixel comprising a series of red, green, and blue light-emitting segments in general alignment and connected by first and second electrodes. The light-emitting segments are built upon a fiber optic core. According to the preferred embodiment, the core is coated with a holographic interface material.

Abstract: The invention relates to a sensor (9) comprising a hologram (17) supported on or within a holographic support medium (10).A species to be detected is reactive with a substance disposed throughout, the sensor (9). Optionally, a chemical reactive with a species to be detected or a specific binding conjugate of a species to be detected is disposed throughout part of or all of the sensor (9).The resulting reaction(s) cause(s) variation(s) in the hologram (17) or holographic support medium (10) which in turn varies one or more optical characteristic(s) of the hologram (17).The variation in the optical characteristic(s) of the hologram (17) and/or the holographic support medium (10), preferably give(s) rise to a wavelength shift in incident radiation. The variation of the optical parameter is related to the species to be detected.The advantages of the sensor are that it is cheap, easy to manufacture and, once calibrated, reliable and robust.

Abstract: A holographic optical device having a light transmissive substrate with a first holographic optical element carried by the substrate, and a second holographic optical element also carried by the substrate but laterally offset from the first holographic optical element. The first holographic optical element diffracts waves from each data point in a display source into a collimated plane wave such that the plane wave is trapped inside the substrate by internal reflection, and the first holographic optical element also corrects field aberrations over the entire field of view by being recorded using at least one aspheric wavefront. The second holographic optical element diffracts the trapped plane waves out of the substrate.

Abstract: A multichip module having high density optical and electrical interconnections between integrated circuit chips includes a substrate overlaying an array of integrated circuit chips. An optical transmitter generates a first optical beam through the substrate and an optical detector receives a second optical beam through the substrate. A hologram is positioned in the path of at least one of the first and second optical beams. An array of electrical contact pads is located on the substrate corresponding to the array of electrical contact pads on the respective integrated circuit chips. A pattern of electrical interconnection lines is located on the substrate for electrically interconnecting the integrated circuit chips. A solder bump between electrical contact pads on the substrate and on the integrated circuit chips establish electrical connections between the substrate and the integrated circuit chips, and also facilitate alignment of the integrated circuit chips with respect to the substrate.

Abstract: A head up display unit equipped at least with transparent and flat image information display means, transparent and flat light irradiating means arranged in an opposed and close contact relationship with the image information display means, light supply means for supplying light to the light irradiating means, image-display control means for controlling image display, and light-supply control means for controlling light supply. The display unit is a compact head up display unit which can be used in any place in the interior of an automobile.

Abstract: A light emitting diode (LED) interconnection package includes an LED situated on a substantially transparent substrate, the LED having a contact surface with contact pads and having side surfaces; a polymer film overlying the contact surface and having via openings; a substantially transparent support piece surrounding the side surfaces of the LED and the substrate; and metallization overlying the polymer film and extending through the via openings for interconnecting the contact pads.

Abstract: A holographic planar concentrator (HPC) for collecting and concentrating optical radiation is provided. The holographic planar concentrator comprises a planar highly transparent plate and at least one multiplexed holographic optical film mounted on a surface thereof. The multiplexed holographic optical film has recorded therein a plurality of diffractive structures having one or more regions which are angularly and spectrally multiplexed. Two or more of the regions may be configured to provide spatial multiplexing. The HPC is fabricated by: (a) recording the plurality of diffractive structures in the multiplexed holographic optical film employing angular, spectral, and, optionally, spatial multiplexing techniques; and (b) mounting the multiplexed holographic optical film on one surface of the highly transparent plate. The recording of the plurality of diffractive structures is tailored to the intended orientation of the holographic planar concentrator to solar energy.

Abstract: A waveguide hologram illumination system is based on thin substrate waveguides bearing a hologram on the surface through which light is diffracted out. A light source is optically coupled to the waveguide such that light emitted from the source is caused to propagate along the waveguide, being diffracted out at intersections with the surface of the waveguide on which the hologram is formed. The selective emission through the hologram can be advantageously used to illuminate display holograms or spatial light modulators. Provisions are made for rendering the amount of light emitted through the hologram uniform along the length of the hologram.

Abstract: A holographic optical interconnect system (100) and method (200) provide flexible, efficient interconnection of a plurality of circuit boards CBs and a plurality of integrated circuit chips. Each CB has at least an optically transparent substrate OTS mate parallel to the CB and extending outside a CB holder. Each OTS mate has parallel sides and carries at least two holographic optical elements HOEs. A first one of the HOEs on a first OTS mate reflects at least a predetermined portion of a first light beam transmitted by a transmitter on a corresponding CB to another HOE, which transmits a received light beam via free space outside the CB holder. On another OTS mate, two HOEs are utilized to receive and direct at least part of the light beam received to a detector on a corresponding CB via free space within the circuit board holder or reflection within the OTS mate.

Abstract: A method and system for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process of the present invention uses thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence, while maximizing the contrast of the slanted fringe structures thereof. A recording medium is in direct contact with a thin substrate whose refractive index is greater than the bulk refractive index of the recording medium. At the substrate interface, the recording medium has a gradient-type index matching region, created by exposure of the recording medium to reference beam illumination, prior to the further application of an object beam to create a fringe pattern.

Abstract: A method and apparatus for automatically providing for both multiplexing and independent external modulation of two or more wavelengths emitted by one or more multi-longitudinal mode laser(s) or other light source. The present invention uses an integrated optics device chip to enable coupling of the dispersed wavelengths into separate electro-optic modulators which encode each of the carrier wavelengths with a different signal. Accordingly, the volume of data which can be transmitted over an optical fiber network is increased. The carrier wavelengths can be transmitted over single or multi-mode optical fibers.

Abstract: A holographic apparatus for continually sensing, transmitting and reconstructing a three-dimensional image including a device for receiving a holographic interference pattern such as a video camera, a device for creating a holographic interference pattern on the receiving device, a device for focusing the interference pattern on the input of the receiving device, a device for transmitting the received holographic interference pattern including a device such as a computer, a device for converting the transmitted holographic interference pattern to a holographic interference pattern which is representative of the three-dimensional image such as an LCD and a source of coherent light illuminating the holographic interference pattern on the converting means to reconstruct the three-dimensional image.

Abstract: A holographic display including a planar transparent light pipe (11) configured for rotation about a light pipe rotation axis that is orthogonal to the planar extent of the transparent light pipe and passes through a rotational center of the light, a multiple image hologram structure (13) having a plurality of holographic images attached to one side of the planar transparent light pipe, wherein the images are at different azimuthal angular positions on the light pipe about the light pipe rotation center, and a light source (17) for illuminating an input surface of the transparent light pipe such that an injected beam propagates within the light pipe to provide reconstruction illumination for a portion of the multiple image hologram structure.

Abstract: Cascaded diffraction grated pairs are employed to form submicron gratings and other patterns in various types of devices using photolithographic, UV exposure and other techniques. Cascaded grating pairs are formed in masks which are positioned between a source of radiation and the device or substrate in which a grating is to be formed. The interaction of the diffracted beams generated by each diffraction grating in a cascade grating pair results in the device grating having a period which is substantially smaller than that of either of the gratings in the cascaded grating pair. As a result, gratings with substantially smaller periods than were previously obtainable can now be achieved using conventional fabrication techniques. To eliminate sensitivity to background exposure in photolithographic fabrication applications, a mask is employed in which first and second cascaded grating pairs are separated from one another by an opaque region that acts as a spatial filter.

Abstract: A product, method, and apparatus are provided for making a stereoscopic hologram from a series of two-dimensional views of an object. The two-dimensional views are obtained from, for example, computer analysis of scans taken by standard medical diagnostic equipment. The views are reproduced on an LCD screen, and the screen then serves as the modulator of the holographic object beam. An exposure of each view is sequentially made on a different section of a holographic recording medium, which may be, for example, a photopolymer placed on a substrate. As the observer views the finished product, each eye looks at a different section of the hologram, thus providing a stereoscopic effect.

Abstract: A holographic thin rear exterior lamp for a vehicle including a light pipe (11) having first and second opposing surfaces (11a, 11b), a rear exterior lamp hologram (13, 113) attached to one of the first and second surfaces of the light pipe, a polarization rotating retarder film (16, 116) attached to one of the first and second opposing surfaces oppositely from the rear exterior lamp hologram, a light source (17, 19) for providing a substantially collimated beam, a transmission hologram (15) disposed on one of the first and second surfaces of the light pipe for coupling the substantially collimated beam into the light pipe such that a portion of the substantially collimated light propagates by total internal reflection within the light pipe, the rear exterior lamp hologram and the polarization rotating retarder film. The polarization rotating retarder film is configured to impart a substantially halfwave retardance to internally reflected light that passes twice therethrough.

Abstract: A multiple image multiplexed holographic display including a light pipe (11, 111) having first and second opposing surfaces (11a, 11b, 111a, 111b) and a plurality of input surfaces (15, 115) located between adjacent edges of the first and second opposing surfaces. A multiple image hologram structure (13, 113) attached to one of the first and second opposing surfaces is illuminated with respective beams injected into the light pipe by a plurality of light sources (17, 50, 61) adjacent respective input surfaces. The injected beams are incident on the hologram structure at different incidence angles, and the hologram structure contains holographic images that are recorded to reconstruct in response to respective injected beams, whereby each holographic image is selectively displayed by controlling its associated light source.

Abstract: A single-line continuous wideband tunable laser utilizes a symmetric or asymmetric grating. By simultaneously altering both the periodicity of the intersections of the grating with the optical axis and the laser effective cavity length, a single-line spectral output is achieved at any desired point in the laser's operating band.

Abstract: Apparatus comprising a decal disposed on an interior surface of a window and a light source for projecting light onto the to display an image outside of the vehicle. The decal comprises a protective layer having a hologram layer disposed thereon that is designed to transmit a holographic image in a predetermined viewing direction. An opaque and clear mask layer into which an icon is incorporated may be secured to the hologram layer to provide a two-dimensional image. The hologram layer is illuminated by sunlight, skylight, or a light source and projects an image to a viewer at a predefined direction. During the day, the icon is viewable because light transmits through the clear portions of the mask layer is clear, and is blocked by opaque portions of the mask layer that define the icon. At night, the decal is illuminated by light from a light source 18, or an exterior or ambient light source to produce an image viewable by the observer.

Abstract: A lamplight device for a vehicle which is inconspicuous when it is turned off is provided. The lamplight device comprises a reflection type or transmission type optical member installed on a predetermined place of a vehicle body either directly or through an appearance member, and is adapted to reflect or refract a light of a specific wave length, a light projecting mechanism for projecting a light of the specific wave length, and a light guiding mechanism for guiding the light projected from the light projecting mechanism to an outer surface or an reverse surface of the reflection type or transmission type optical member.

Abstract: An optical transmission system having a transmission waveguide, an optical amplifier, a pump radiation source for supplying pump radiation to the optical amplifier, and a Bragg grating for reflecting pump radiation to the amplifier. The Bragg grating is produced using two collimated, non-collinear beams of actinic radiation to form an interference pattern in a medium. While changing the product .lambda..times.0.5 csc .phi./2, the interference pattern is advanced relative to the medium such that the interference pattern has a spatially varying period. The resulting Bragg grating has a sufficiently wide bandwidth in reflection, sufficiently high extinction in transmission, and sufficiently low intrinsic loss that the pump radiation source may be located at least one kilometer from the optical amplifier.

Abstract: A method and system for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process of the present invention uses thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence. Different recording techniques are employed when the index of refraction of the substrate is greater than that of the recording medium, than when the index of refraction of the substrate is less than that of the recording medium.

Abstract: An improved holographic backlight and liquid crystal display system. The holographic backlight comprises a cold cathode fluorescent tube for providing white light, and a light pipe disposed to receive the white light. A phase retarding film layer is attached to a first surface of the light pipe. A double-layer reflection/transmission hologram is disposed on an output surface of the light pipe opposite the film layer. Light from the cold cathode fluorescent tube is injected into the light pipe, and is diffracted off of the double-layer hologram. This produces quasi-collimated s-polarized light having well-defined spectral colors that is transmitted by the hologram in an array of red, green, and blue patches of light corresponding to the clear apertures of the red, green, and blue elements of an active matrix liquid crystal display. The result is a liquid crystal display with high display brightness, reduced battery power requirements, increased battery lifetime, and high contrast over a wide viewing angle.

Abstract: A multichip module having high density optical and electrical interconnections between integrated circuit chips includes a substrate overlaying an array of integrated circuit chips. An optical transmitter generates a first optical beam through the substrate and an optical detector receives a second optical beam through the substrate. A hologram is positioned in the path of at least one of the first and second optical beams. An array of electrical contact pads is located on the substrate corresponding to the array of electrical contact pads on the respective integrated circuit chips. A pattern of electrical interconnection lines is located on the substrate for electrically interconnecting the integrated circuit chips. A solder bump between electrical contact pads on the substrate and on the integrated circuit chips establish electrical connections between the substrate and the integrated circuit chips, and also facilitate alignment of the integrated circuit chips with respect to the substrate.

Abstract: A method for forming a grating in a photosensitive medium such as a photosensitive optical fiber. The method comprises impinging a pair of interfering, actinic beams onto the medium, and during the impinging step, advancing the illuminated portion of the interference pattern relative to the medium. The advancement is carried out without changing the phase, or registration, of the interference pattern. According to one embodiment of the invention, a grating having a spatially dependent period is produced by varying the wavelength or the intersection angle of the actinic beams during the advancement. According to a second embodiment of the invention, a grating having a spatially dependent refractive index perturbation is produced by varying the dose of actinic radiation received by the medium during the advancement.

Abstract: Systems and methods for universal remote lighting systems are described. A high definition universal remote lighting system includes a light source that is coupled to a light pipe, a high efficiency nonimaging total internal reflection light transformer design and a high efficiency holographic diffuser for shaping the light. The present invention can also include an optical switch device for direct light output monitoring. The systems and methods provide advantages such as cost reduction, better monitoring and control, maintenance simplification, enhanced personnel safety, electromagnetic impulse (EMI) insensitivity, reduced radar and weight/size reduction.

Abstract: A device for transmitting radiation is provided. The device includes a glass optical waveguide having a core. A Bragg grating is at least partially formed within the core. Associated with the Bragg grating is a transmission spectrum that includes a band in which incident radiation is attenuated, the peak attenuation being at a wavelength .lambda.. The transmission spectrum of the Bragg grating is such that the full width at half maximum measured in transmission is greater than or equal to (1.5 nm/1558.5 nm) .lambda. and peak attenuation within the band is greater than or equal to 90% of full scale transmission. Attenuation exceeds 50% of the peak attenuation everywhere within the full width at half maximum of the transmission spectrum.

Abstract: A method and apparatus for automatically providing for both multiplexing and independent external modulation of two or more wavelengths emitted by one or more multi-longitudinal mode laser(s) or other light source. The present invention uses an integrated optics device chip to enable coupling of the dispersed wavelengths into separate electro-optic modulators which encode each of the carrier wavelengths with a different signal. Accordingly, the volume of data which can be transmitted over an optical fiber network is increased. The carrier wavelengths can be transmitted over single or multi-mode optical fibers.

Abstract: The fiber optic-based correlating and sensing system (the System) utilizes length of optical fiber through which the object beam travels prior to being incident on the holographic plate. First, a matched filter is created on the holographic plate of the initial condition of the environment. Then when the plate is re-placed in its original position in the System and the reference beam is blocked from reaching the plate, a correlation peak appears as the object beam passes through the holographic plate. To use the System as a correlator, the object beam is transmitted through an input scene prior to its travel through the optical fiber. The changes in the input scene from the initial scene causes broadening of the shape of and degradation of intensity of the correlation peak. To use the System as a sensor, the object beam travels through the optical fiber acquiring information regarding the environment surrounding the fiber, such as pressure, temperature, sound, electric and magnetic fields.

Abstract: Computation-intensive applications such as sensor signal processing, sensor fusion, image processing, feature identification, pattern recognition, and early vision place stringent requirements on the computational capacity, size, weight, and power dissipation of modular computational systems intended for both embedded and high performance computer environments. Such ultra high speed, ultra high density computational modules will typically be configured with multiple processor, memory, dedicated sensor, and digital signal processing chips in close-packed multichip modules. The present invention relates to a novel architecture and associated apparatus for the development of highly multiplexed photonic interconnections between pairs of such electronic chips incorporated in vertical stacks within three-dimensional multichip module configurations.

Abstract: A flexible fiber optic delivery system for medical and industrial applications is described that can transmit high laser power densities and optical images. A parabolic-index profile of a graded-index fiber is perturbed so as to prevent strong localization of a laser beam in the fiber's recurring focal regions. This permits transmission of high laser powers without danger of fiber damage. An additional gain in carrying capacity for the system is achieved by using a wavefront perturbation system between the laser source and the graded-index fiber. Optical image transmission is achieved by using a measured perturbation to a parabolic-index profile of the graded-index fiber with a prescribed length and a wavefront reconstruction system in combination with the wavefront perturbation system. The system has an increased laser induced damage threshold and can transmit highly focused optical images.

Abstract: A Bragg reflection filter wavemeter is used to measure transverse holographic gratings and optical fibers and utilizes a first interferometer which is always fixed with respect to the optical fiber and a second adjustable interferometer. The optical fiber and first interferometer are mounted on a translating support while the second interferometer includes a pair of angularly adjustable mirrors for changing the angle at which the object and reference beams thereof intersect the fiber. Since the fiber is mounted on a movable support, the position of the support can be continually adjustable so that the reference and object beams always intersect the fiber at the same point, regardless of the angle assumed by the reflecting mirrors. The resulting interference patterns are projected by an objective lens to the far field in which a linear scanning, photodiode array is moved.

Abstract: A method is described for selectively modifying the refractive index of an optically transmissive body having an optical propagation axis. According to this method, polarized, actinic radiation is impinged on at least a portion of the body. In contrast to methods of the prior art, the actinic radiation is at least 60% polarized with a polarization direction parallel to a plane containing the propagation axis.

Abstract: The present invention is a holographic structured light generator (HSLG) for generating an array of an arbitrary number of laser beamlets from a single laser beam using a point laser light source and a hologram. In a first preferred embodiment of the present invention, a hologram having an image of four point sources in a common plane is fabricated using four point sources as the object beam, and a reference beam. A reconstruction beam, aligned identically with respect to the hologram as was the reference beam during fabrication of the hologram, is then directed at the hologram, generating the array of laser beamlets from the four point sources in the hologram. In a primary application of the HSLG, it is used to map the surface of an object in three dimensions. The HSLG is used with video cameras, computer image processing equipment and an optical spatial light modulator to yield 3-D data for use with CAD systems.

Abstract: The present invention is based on the use of a plurality of gratings recorded in an optical waveguide, the gratings having different Bragg wavelengths selected to store individual bits of data. The invention has particular application to optical fiber communications networks.