Abstract: A grating structure useful for WDM multiplexer/demultiplexer applications is described. The grating structure has a substantially polarization-independent diffraction efficiency of a predetermined useful wavelength range, for example, between 1.4 and 1.6 &mgr;m. Each grating period includes a triangular section and a flat-topped section, with the width of the flat-topped section between 20 and 50% of the grating period. The disclosed grating structure can be formed in any material that is substantially transparent over the useful wavelength range and used in either a Littrow and a Littman-Metcalf configuration.

Abstract: A waveguide for decreasing signal propagation delay including an evanescent region and an amplification region. In various embodiments, the evanescent region includes varying index of refraction regions, such as one or more thin film regions and one or more fiber Bragg grating regions, one or more frustrated internal reflection constructs, or one or more undersized waveguides. In various embodiments, the amplification region includes doped amplifiers and other amplifier types that use propagated pump photons to provide amplification, or semiconductor amplifiers or other amplifier types that use electrical power to provide amplification. A method for decreasing signal propagation delay includes propagating a signal having a signal frequency into an evanescent region. After propagation through the evanescent region, amplifying the attenuated signal.

Abstract: A bi-directional amplifier system comprises a 2×2 interleaved channel separator optically coupled to both a first and a second bi-directional fiber optic communications line and an optical amplifier optically coupled to the 2×2 interleaved channel separator.

Abstract: A method and optical mode transform device is given whereby an optical waveguide positioned on a support substrate for receiving light from a optical fiber passing through a mode-matcher converting light from one mode to another to minimize optical loss.

Abstract: An optical coupler comprises a fiber optic prism (FOP) comprising first, second, and third side surfaces, the FOP being adapted to receive light through the first side surface, reflect the received light from the third side surface, and transmit the reflected light through the second side surface. The FOP may be used in an optical coupling arrangement comprising a substrate including a light element and a wave guide overlying the substrate, with the optical being situated such that one of the first and second side surfaces is adjacent the light element and the other of the first and second side surfaces is adjacent the wave guide.

Abstract: The present invention provides an improved chromatic dispersion compensator. The compensator includes an input optical fiber; an output optical fiber; a collimator optically coupled to the input and output optical fibers; and an interferometer optically coupled to the collimator at a side opposite to the input and output optical fibers. In a preferred embodiment, the interferometer is a Gires-Tournois interferometer. A plurality of sequentially optically coupled chromatic dispersion compensators may also be used. The compensator in accordance with the present invention provides flexibility in producing periodically varying chromatic dispersion so as to compensate for unwanted periodic chromatic dispersion produced in an interferometric interleaved channel separator. Also, the compensator enables compensation of fiber optic chromatic dispersion.

Abstract: An optical add/drop multiplexer to be tuned locally or remotely, to compensate for drift in operation, and to facilitate installation or replacement at remote terminals.

Abstract: An optical waveguide extends vertically within the interior of an IC-like structure to route optical signals between horizontal waveguides in different layers of horizontal optical interconnects. A light reflecting structure is positioned at the intersection of the horizontal and vertical waveguides to reflect the light. Multiple horizontal waveguides may join the vertical waveguide at a common intersection, to form a beam splitter or a beam combiner. Optical signals from one horizontal waveguide are diverted within the IC-like structure into another horizontal or vertical waveguide. The waveguide is formed with a light reflective structure at an intersection of the horizontal and vertical waveguides, and the waveguide is completed using damascene fabrication techniques.

Abstract: A variable attenuator employs a shutter element that is inserted into the path of a beam of radiation. The shutter element comprises a transparent substrate with an opaque layer formed on top of the substrate. The opaque layer forms a pattern in the shape of dots on one part of the substrate and in the shape of a solid layer with holes therein on another part of the substrate. The pattern of holes and dots are such that the radiation transmission function of the element varies as a smooth linear function with the length of the shutter element. Therefore, by inserting the shutter element in a direction along its length into the path of the radiation beam, the amount of attenuation of the beam can be accurately controlled.

Abstract: A light guide configuration for serial bi-directional signal transmission includes an optical signal line for carrying electromagnetic radiation along a main direction of the line, optical accesses disposed along the main direction for coupling electromagnetic radiation in and out along a direction running substantially perpendicular to the main direction of the line, and diffusers disposed inside the optical signal line and allocated to an optical access, respectively. Each of the diffusers works in conjunction with the allocated optical access such that a portion of the radiation that is carried in the optical signal line can be coupled out of the optical signal line by the diffuser through the allocated optical access, and radiation entering through the optical access can be coupled into the optical signal line through the allocated diffuser. An optical circuit board having the configuration and a method for fabricating the optical circuit board are also provided.

Abstract: An optical switch using a refractive optical element (52) to direct a light beam in selected directions upon operation of the switch. In a preferred embodiment, the refractive optical element is an optical wedge having a first portion (67) that transmits a light beam in a selected direction, and a second portion (50) that transmits the light beam in another direction, when the first or second portions of the optical wedge are switched into the path of the light beam. The refractive optical element is less sensitive to misalignment than a reflective element, for example. In a further embodiment, the optical wedge is combined with wavelength-selective filters (118, 128) and other components to provide a channel DROP and/or ADD function with high isolation.

Abstract: The present invention provides an optical switching element causing less loss of light and permitting high response, thinning of an optical system for illumination, and the realization of an image display device exhibiting precise grayscale properties. In the optical switching element, an extraction surface of a light extraction unit mounted to a thin film is brought into contact with the total reflection surface of a light guide serving as a light guide unit comprising a glass plate or the like for transmitting light by total reflection, or near at a distance from the total reflection, surface for allowing extraction of evanescent waves, to extract the incident light transmitted through the light guide and emit the extracted light to the outside through an emission member.

Abstract: In an optical transmission and reception module, a partitioning member separating a light emitting device and a light receiving device from each other includes a partitioning plate having a concave surface, an engaging portion to which the partitioning plate is fixed, a holding portion holding the engaging portion movably, and a leaf spring for pressing the engaging portion against an optical plug. An end surface of an optical fiber is convex and projects from a front end of the optical plug. When the end surface of the optical plug is in contact with an engaging surface of the engaging portion, a gap is generated between the end surface of the optical fiber and a surface opposed thereto.

Abstract: An optoelectronic device with an array of passive optical elements mounted thereon which provide optical communications between the active optical elements of the transceiver array as well as optical signal processing.

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: The present invention provides a line of optical interleavers in which a novel beam-swapping element is utilized. The beam-swapping element of the present invention provides an effective and inexpensive alternative to polarization rotators and birefrigent elements employed in the prior art optical interleavers, hence rendering a simple and low-cost assembly to the optical interleavers of the present invention. The optical interleavers of the present invention further advantageously exploit a combination of two wavelength filters to cancel out wavelength-filter-induced-dispersion. Efforts are also painstakingly made in the optical interleavers of the present invention to substantially minimize other dispersion effects. As such, the optical interleavers of the present invention constitute the first kind in the art in which various dispersion effects are substantially minimized. Such characteristics would be highly desirable in fiber-optic networks.

Abstract: A fiber optical circulator in which is a light beam is fed from a fiber of a first port in a dual core glass capillary, then collimated before being passed to a birefringent crystal wherein the light beam is divided into two orthogonal components o and e with a displacement. The State of Polarization (SOP) of components then are changed into the same, perpendicular to the incident plane of the birefringent crystal prism by the group of Faraday Rotator and two Half-Wave Plates (HWP) that have different optical axis orientation and cover o and e components respectively. Then the light components with the same SOP pass into a birefringent prism where they receive angle correction to meet receiving requirement in incident angle for the fiber of port 2 without displacement due to their SOP. This is followed by a second group of HWP and Faraday Rotator that changes the SOP of two components back to orthogonal.

Abstract: A first surface of an optical component has a lens function of converging the transmission light from a light source. A second surface reflects the transmission light, converged by the lens: function of the first surface, towards an end face of an optical transmission medium as the destination of transmission. The light reflected by the second surface is radaited from a coupling surface. Since the light beam from the light source is directed towards the optical transmission medium by exploiting the total reflection of light, a high-reflection multi-layer film or a polarization beam splitter film, required in a conventional apparatus employing a polarization beam splitter, is unneeded, with the result that the film forming cost or the cost in bonding two prisms used for fabricating the polarization beam splitter may be dispensed with. In this manner, the production cost or size of the apparatus can be reduced withut lowering the transmission/reception performance.

Abstract: Optical isolators for use in fiber optic networks utilizing a birefringent wedge set with a Faraday rotator disposed between the birefringent wedges. In a first embodiment a polarization maintaining optical isolator is disclosed which will maintain the polarization of the light which passes through it in a forward direction and block light in the reverse direction. In a second embodiment a single polarization optical isolator is disclosed which will pass only a single linear polarization of the light in a forward direction and block any light in the reverse direction.

Abstract: An optical fiber bend sensor (10) measures the degree and orientation of bending present in a sensor length (30) portion of a fiber assembly (26). Within a multicored fiber (30, 32,34), cores (62, 66) are grouped in non-coplanar pairs. An arrangement of optical elements (28, 36, 38) define within each core pair (62, 66) two optical paths (122, 124) which differ along the sensor length (30): one core (62) of a pair (62, 66) is included in the first path (122), and the other core (66) in the second path (124). A general bending of the sensor region (30) will lengthen one core (62, 66) with respect to the other. Interrogation of this length differential by means of interferometry generates interferograms from which the degree of bending in the plane of the core pair is extracted. Bend orientation can be deduced from data extracted from multiple core pairs.

Abstract: An optical isolator having a constitution in which a Faraday rotator is sandwiched by two polarizers, which can be more easily produced at a reduced cost. An optical isolator is constituted so that it comprises the following constituent elements in the described order: a first reflection-type polarizer made of a polymeric multilayer film; a Faraday rotator capable of rotating the polarizing. plane by 45 degrees; a tapered glass plate; and a second reflection-type polarizer made of a polymeric multi-layer film.

Abstract: An optical fiber amplifier employing a prism to optimally couple pump energy into the pump core of a dual clad fiber. The optical fiber amplifier consists of a dual clad fiber having an inner (e.g., signal) core, an outer (e.g., pump) core surrounding the inner core, and a cladding layer at least partially surrounding the outer core. Pump energy can be injected into the outer core through the prism located adjacent to the outer core in order to amplify signals propagating through the inner core.

Abstract: An apparatus and method for coupling an array of light beams extending predominantly in one direction into an output port. The light beams are rearranged into a desired shape which extends more equally along two directions than does incident array of light beams. The operation of the rearranging is wavelength insensitive. The rearranged light beams are focused onto the output port. For output ports having a small interface, the focal length of a lens focusing the rearranged light beams to the output port should be as short as possible.

Abstract: An N×N optical switching array device and system are disclosed. In one aspect, an optical switching device for communicating optical signals is provided. The device includes a plurality of optical inputs operable to communicate optical signals, a plurality of optical outputs optically coupled to the optical inputs and at least one thermo-optic array optically coupled to the plurality of optical inputs and the plurality of optical outputs. The device further includes an thermo-optical array operable to deflect an optical signal from one of the plurality of optical inputs to one of the plurality of optical outputs in response to a temperature differential.

Abstract: The invention relates to wavelength division multiplexing (WDM) and demultiplexing of optical signals using optical filters in free space. To minimize dispersion, the present invention uses relatively small angles of incidence. To avoid the need for a large package, the present invention utilizes reflective prisms to steer the reflected beams to provide a lateral shift in the beam path that ensures that the necessary space is provided between the input/output ports. Devices including a single adjustable filter are disclosed, along with devices having a plurality of filters.

Abstract: A rotating handpiece is disclosed, having a parabolic mirror coupling to optical fibers which are disposed perpendicularly to an input optical fiber and an output optical fiber. The output optical fiber of the two is adapted to rotate relative to a longitudinal axis of the input optical fiber.

Abstract: An optical coupling device for coupling optical waveguide devices having different spot sizes to one another includes photonic crystal having a modulation structure having a refractive index periodic at about the same interval as the wavelength of light used by the optical waveguide devices. The use of the photonic crystal allows the spot size of light at the emitting end of the photonic crystal to be converted into a different size from the spot size at the incident end of the photonic crystal.

Abstract: Method and apparatus are disclosed for beam dividing and shaping, in which the beams from laser diode array are divided in a plurality of sections along the slow axis and the sections of beams are then recombined along their fast axis so that the Lagrange invariant of the resulting beam increased approximately by n-fold in fast axis and reduced approximately by n-fold in slow axis. With the inclusion of above apparatus in diode laser modules, the main objectives of constructing high-efficiency solid state lasers can be achieved.

Abstract: A device for optically interconnecting a plurality of devices. In one embodiment, the disclosed optical interconnection device includes a plurality of optical ports. One embodiment of the presently described optical interconnection device includes optics elements to optically couple each one of the optical ports to one another. In one embodiment, these optical elements include one or more beam splitters and deflectors. Each of the optical ports of the presently described optical interconnection device is configured to be optically coupled to another device, such as for example an integrated circuit chip, computer system or the like, through an optical link. In one embodiment, the optical ports accommodate a plurality of N optical beams providing an N-bit wide multi-load optical bus.

Abstract: An X-cube integrated solid-optics component which can perform beam-splitting and filtering functions among four input beams. The X-cube component can also be used for various wavelength-division multiplexing communication and interconnection applications, such as star-coupling, wavelength routing, and add/drop multiplexing. The X-cube component comprises an assembly of four right-angle roof-top prisms positioned with the apex of each roof-top prism at the center of the assembly, such that assembly defines two mutually orthogonal and intersecting internal planes which intersect at the center of assembly to form four sections of the intersecting internal planes. The four plane sections form up to four or more primary optical channel paths having up to four or more potential inputs IAI, IBI, ICI, IDI and four or more potential outputs IAO, IBO, ICO, and IDO, and the outputs depend upon functionalities provided by the four sections of the intersecting internal planes.

Abstract: The invention discloses an optical deflection switch which uses the output focal plane of a lens more effectively. This is achieved by combining a tapered block of a light-transmissive material having a reflective surface and a second face, wherein the second face includes an input/output port and the reflective surface provides reflection of a beam of light passing through the input/output port into the tapered block with a first block of a light-transmissive material having a first face and a second face, wherein the first face includes an input port thereon for receiving a collimated beam of light and the second face is for providing total internal reflection of the beam of light in a first switching state and for acting as an output/input port for optical communication with the input/output port of the switching block when the total internal reflection is frustrated in a second switching state.

Abstract: A one-sided switch for redirecting light between adjacent ports. The switch uses a moveable refractor, in combination with a lens and a stationary reflector, to redirect light from one optical port to another. In a most simple embodiment light is redirected from one output port to another by repositioning the refractor in the optical path of the light and using only a single lens for collimating and focussing the light at the reflector and about the ports, respectively.

Abstract: To provide an information recording and reproducing apparatus for supplying light for generating near-field light to a near-field light head, generating a sufficiently large amount of near-field light at a vicinity of a very small opening and realizing reproduction and recording with ultra high resolution, recording and reproduction at high speed and high SN ratio formation, in an information recording and reproducing apparatus constituted by a record medium 107, a light source 101, a suspension arm 109, a flexure 110 fixed to the suspension arm 109, a near-field light head 301 fixed to the flexure 110 and having a very small opening on a side of the record medium 107, a light guiding structure 103 for guiding light flux from the light source 101 to the near-field light head 301 and a light receiving portion 108, the very small opening and an optical wave guide for guiding light to the very small opening are disposed on the same side of the near-field light head and the light guiding structure is constituted

Abstract: An optical axis conversion lens includes an incident surface on which the light emerging from a slab light guide is incident, a cylindrical lens surface which has an optical axis C in a position or direction different from an optical axis A of the light incident on the incident surface and which converges the light in the direction of the optical axis C, a first internal reflection mirror which changes the direction of the incident light from the incident surface to an optical axis B, and a second internal reflection mirror which changes light on optical axis B to an optical axis C. By such an arrangement, it is possible to convert light on the optical axis A to the optical axes B and C without being limited by the height of the slab light guide and to form a narrow beam even at a position far away from the slab light guide.

Abstract: Switch arrays are provided with controllable polarization modifiers and polarization-dependent diverters, such as one or more polarization beam splitters, for configuring switch arrays which can reduce or eliminate the need for optical fibers in the switch arrays. In one embodiment, input positions configured in a first preferably planar (e.g., horizontal) configuration are routed to one or more of a corresponding plurality of output positions which are configured in a different arrangement such as in an orthogonal (e.g., vertical) planar arrangement. Preferably some or all of the polarization-related optical components, including components such as birefringent devices, liquid crystal polarization rotator arrays and/or polarization beam splitters are integrated so that one such device can be used in connection with a plurality of input and/or output beams.

Abstract: A pixel of a display device is controlled by a tilting mirror. When the mirror is in a first position, light from a light source is directed to a light diffusing structure for viewing. If, however, the mirror is tilted, the light is directed along a path which prevents it from entering the light diffusing structure. Thus, the brightness of a pixel is controlled by tilting a mirror. In one embodiment, the colour of an individual pixel can be controlled by controlling the degree of tilt of a mirror.

Abstract: Disclosed is a luminaire including a housing for receiving light axially and having at lest one optical surface for emitting light. A lens is mounted in the housing and has a light input portion and a light output portion. A prismatic film is mounted in the housing onto which light output from the output portion of the lens is incident thereon wherein light is reflected by the prismatic film radially outwardly therefrom.

Abstract: A light (1) comprises a light source (4) and a wedge-shaped light guiding element (3) having two wedge surfaces (11, 13) and a light entry face (10) extending between the wedge surfaces where they are farthest apart. Light from the source (4) enters light guiding element via the face (10) and is reflected by one wedge surface (13) against the other wedge surface (11) where it exits from the light guiding element (3). To improve radiation characteristics, the other wedge surface (11), which is an exit surface, is profiled with adjacent elevations and indentations extending crosswise to the direction of the wedge. A transparent diffuser (20) is positioned at a distance in front of the exit surface (11). The side of the diffuser (20) facing away from the light exit surface is profiled with adjacent elevations and indentations. The distance between the diffuser (20) and the light guiding element (3) prevents light from entering the diffuser at any angle and thus increases the effectiveness of the profiling.

Abstract: A single channel M×N optic switch is provided in accordance with the present invention to steer light radiating from any one fiber in an input bundle into any selected fiber in an output bundle. Precision beam-steering optics is implemented using a Risley prism pair controlled by a small computer. In order to efficiently couple light between two single-mode optical fibers a low-aberration lens approximately collimates the light from the source fiber before it is passed through the Risley prisms in order to minimize the aberrations introduced by the prisms as they collectively deflect the beam through some precise angle. A second low-aberration objective lens is used to refocus the light at the core of a selected output fiber. The focusing lens transforms the angular deflection of the beam into a change in the position of the focused spot in the focal plane of the lens.

Abstract: An optical waveguide extends vertically within the interior of an IC-like structure to route optical signals between horizontal waveguides in different layers of horizontal optical interconnects. A light reflecting structure is positioned at the intersection of the horizontal and vertical waveguides to reflect the light. Multiple horizontal waveguides may join the vertical waveguide at a common intersection, to form a beam splitter or a beam combiner. Optical signals from one horizontal waveguide are diverted within the IC-like structure into another horizontal or vertical waveguide. The waveguide is formed with a light reflective structure at an intersection of the horizontal and vertical waveguides, and the waveguide is completed using damascene fabrication techniques.

Abstract: An optical device and method for bidirectional communication in both high and low bit rate applications simultaneously using a polarization-sensitive beam splitting cube and optical port assemblies. The device provides optical isolation for a transmitting laser optic source and provides optical reflection of an optical beam to a receiver, simultaneously, over a single fiber optic link.

Abstract: A fiber optical circulator wherein optical fibers of three ports share one glass capillary, one collimator lens and one walk-off crystal. Three optical fibers lie on a plane in a glass capillary that is aligned with a collimator lens concentrically. A light fed into the fiber of port 1, which is off optical axis of collimator lens, is collimated with an angle &thgr; to the axis of collimate lens. The collimated beam is divided into two orthogonal components by a first crystal. A device group consisting of one Faraday rotator and one pair of Half Wave Plates transfers the State Of Polarization (SOP) of two components into the same. The angled part of a combined prism bent both beams to be parallel to optical axis of system. The lights pass through a second crystal without displacement due to their SOP. Their SOP receive 90° rotations by a round trip in followed Faraday rotator with help of a reflection film on the backside or a mirror.

Abstract: A miniature monolithic optical demultiplexer that comprises a dispersive optical element and a wavelength filter array. The miniature monolithic optical DWDM demultiplexer can be fabricated using micro- and nano-scale techniques common to the semiconductor industry. The operating principles and some characteristics of the DWDM demultiplexer are described. The device will be useful in the field of optical communication as a component within networks that perform all of the necessary switching, adding, dropping, and manipulating of optical signals entirely in the optical domain. With the inclusion of additional components, exemplary optical communication devices that can be built using the DWDM demultiplexer include optical add/drop multiplexers (OADM), Dense Wavelength Division Multiplexing (DWDM) routers, tunable filters, optical cross connects, and the like.

Abstract: A miniature monolithic optical add-drop multiplexer that comprises a dispersive optical element, a wavelength filter array and a diverter. The miniature monolithic optical DWDM add-drop multiplexer can be fabricated using micro- and nano-scale techniques common to the semiconductor industry. The operating principles and some characteristics of the DWDM add-drop multiplexer are described. The device will be useful in the field of optical communication as a component within networks that perform all of the necessary switching, adding, dropping, and manipulating of optical signals entirely in the optical domain.

Abstract: An optical communications apparatus and method of using same in which optical coupling between an optical medium and a light emitter and a light receptor is achieved without any optical system therebetween. A minor axis of light transmission pattern on an end face of the optical fiber corresponds to the radial direction of the end face while a center C of the light emitter is displaced off from a center axis O, thereby providing improved optical coupling efficiencies.

Abstract: Embodiments of the invention include an optical communications system including an apparatus and method for laterally displacing or otherwise steering optical signals passing therethrough. The system comprises a launching device for launching or transmitting an optical signal, a receiving device for receiving an optical signal, and at least one optical guiding element. The optical guiding element is a transmission medium that captures and transmits optical information therethrough and is configured, e.g., via end geometries, to redirect a portion of light propagating in a first direction and entering the first end substantially along its transmission axis and to redirect light propagating along the transmission axis out of the second end in a desired direction, e.g., a second direction laterally displaced from the first direction. Embodiments include angled faces with or without reflective coatings and attached lenses opposing the angled faces.

Abstract: A 1×N mechanically actuated optical switch includes a plurality of optical reflectors, at least some of which are movable between their on and off positions to switch an input optical signal to any one of a plurality of output optical fibers selected for outputting the optical signal.

Abstract: A coupling for an optical device that disperses wavelengths along a focal line includes reflective surfaces that fold light out of a plane propagation and into alignment with an array of inputs or outputs. Some of the reflective surfaces are offset from the focal line so that the inputs or outputs can be spaced closer together in a dimension along the focal line.

Abstract: A backlight apparatus has a collimating waveguide with a light input end, a top surface, a bottom surface, opposing sides, a far end opposite the light input end, and a total internal reflection critical angle for the material of the waveguide. A plurality of first facets are formed in the bottom surface distributed along the waveguide between the light input end and the far end. Each of the first facets has a first facet bottom surface which converges toward the top surface in a direction away from the far end relative to the top surface. A light scattering and reflective surface is disposed adjacent the far end of the collimating waveguide. The first facet bottom surfaces cause light rays entering the light input end to be totally internally reflected to the far end of the collimating waveguide wherein the scattering and reflective surface at the far end reflects and scatters light rays incident thereon back toward the light input end.

Abstract: A positive-powered lens for directing and organizing the light output from a single light to a plurality of optical fibers has an anterior surface, which is convex, and a posterior surface, upon which are disposed light-converging tessellates, which are arranged in an ordered geometrical (e.g. a square, rectangular, circular, or oval) pattern. The tessellates can have a common surface equation or can have different surface equations but equivalent focal lengths. The tessellates are associated with a plurality of optical fibers, each having a proximal face, which is coplanar with the focal planes of the tessellates.