Abstract: Composite cables operative to transmit information in optical transmission and/or electrical power modes. The composite cables include an optical fiber operative to transmit light comprising a silica-based core with a silica-based cladding having a lower index of refraction than the core, the core and cladding are surrounded by two layers of plastic that define a soft primary coating surrounding and in contact with the cladding, and a relatively rigid secondary coating that surrounds and is in contact with the primary coating. The optical fiber has an outside diameter of about 250 &mgr;m to about 500 &mgr;m or more, and an electrical conductor surrounds the secondary coating. The composite cable includes an outermost cable jacket layer having an outside diameter of about 3,500 &mgr;m or less.

Abstract: A method of creating an optical filter for selectively filtering an optical signal transmitted through the filter, the method comprising: constructing a Bragg grating in an optical element coupled to an optical path way for the transmission of the optical signal to suppress background radiation; and adjusting the coupling so as to produce a selective transmission spectrum in according with predetermined requirements.

Abstract: The arrangement has at least two electrooptic transducers (1, 2) with in each case one optically active zone (1a, 2a). Optical connections (12, 14) which are assigned to the transducers are adjacent at a spacing (a). Optical coupling paths (8, 9) run via a coupling device (6) between the connections (12, 14) and the respectively assigned optically active zones (1a, 2a) In order in the case of a very tight spacing (a) to permit a favorable crosstalk response and a cost effective design, the coupling paths (8, 9) run in such a way that the spacing (A) between two optically active zones (1a, 2a) is greater than the spacing (a).

Abstract: A polarization insensitive photonic information router that can use polarization sensitive switches is disclosed. A photonic input signal is polarization separated into two paths having mutually orthogonal fixed polarizations and complementary amplitude fluctuations in accordance with polarization fluctuations of the input signal. Duplicate-acting switches, one for each fixed polarization, produce switched, polarized signal pairs. These are connected so as to recombine energy from both polarization contributions in each of the switched outputs. Recombining can standardize output polarizations, or reproduce the input polarization fluctuations. Polarization stabilization can also be used before switching. Decoding packet data to operate the switch produces a polarization insensitive packet switching router.

Abstract: A dilated N×N optical cross-connect switch suitable for large N exhibits good efficiency (element count) without a significant increase in and reduced small depth (low loss) and crosstalk. The present arrangement consists of six levels of binary trees of 1×2 and 2×1 elements. The first two levels form the input stage, the third and fourth levels form the center stage, and the fifth and sixth levels form the output stage. In each of the input, center, and output stages, the odd number level is formed as a binary tree of 1×2 elements and the even numbered level is formed as a binary tree of 2×1 elements. Each stage is formed by directly joining together the 1×2 element binary tree with the 2×1 element binary tree. In one embodiment, depth is substantially reduced by using a symmetric arrangement of one or more 2×2 elements located in the vicinity of each junction between adjacent stages.

Abstract: A planar-mounted optical waveguide transmitter-receiver module, in which a plurality of separated silicon substrates and a PLC substrate are hybrid-integrated, is provided. In this module, electrical crosstalk between the light emitting element side and photo-receiving element side is reduced, and adhesion area between substrates is decreased. In this module, a first silicon substrate, on which are mounted a light emitting element and photo-receiving element, is positioned opposing a second silicon substrate, in which is formed a V groove, in which an optical fiber is to be inserted and fixed in place with resin or by other means. On joining surfaces of the first silicon substrate and joining surfaces of the second silicon substrate are positioned and fixed in place joining surfaces on the back face of an optical waveguide (PLC) substrate, in which is formed an optical waveguide.

Abstract: A piezoelectric optical switch includes a planar Mach-Zehnder optical device having a piezoelectric rib disposed on one or both of the waveguide structures. The piezoelectric rib deforms the waveguide structure creating a strain vector that alters the optical path of the waveguide. The piezoelectric rib is offset from the propagation path in the waveguide. This yields several important advantages. By positioning the piezoelectric rib away from the waveguide, the strain components in the propagation path of the waveguide in the directions perpendicular to the direction of propagation, e.g., in the x-direction and the y-direction, are negligible. Since strains in these directions create birefringence, elimination of these strains will minimize the birefringence. The elimination or reduction of birefringence is greatly desired because birefringence degrades the extinction ratio at the outputs of the Mach-Zehnder device.

Abstract: A number of micromachined optomechanical switching cells and matrix switches including such switching cells are disclosed herein. One optomechanical switching cell of the present invention includes a parallel plate actuator positioned on a substrate. A mirror coupled to the actuator is disposed to selectively redirect an incident optical beam. The present invention also contemplates an optomechanical matrix switch including a substrate and a plurality of optomechanical switching cells coupled thereto. The matrix switch further includes an arrangement for monitoring the optical power incident upon, and output by, the matrix switch.

Abstract: An optical switch is disclosed which operates as binary or digital switch. Two glass waveguides are arranged in an X-like pattern such that they approach each other at a waist region without crossing over one another. A polymer region contacts both waveguides at this waist region and has a refractive index that can be changed more than that of the adjacent glass by applying heat. The refractive index of the polymer can be varied from an index which is same as the glass waveguides; to be less than that of the glass in which case the polymer acts as a cladding. When the index of the polymer is lower than that of the glass through the application of heat, light launched into one of the waveguides continues along the waveguide via total internal reflection and no light crosses the glass polymer boundary.

Abstract: Disclosed is a hybrid waveguide structure, wherein a core or cladding has a hybrid section or “button” of a different optical property such as refractive index from the major portion of the core or cladding, respectively. The hybrid section can be made of a passive material or an electro-optic material. Methods of making a hybrid waveguide structure are also disclosed. These methods include rib-based methods and trench-based methods, and in either of these methods, a temporary filler is used in many instances to incorporate the hybrid section into the hybrid waveguide structure.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr;c. The core includes at least three radially adjacent regions, a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2 and an annular ring region having a refractive index &Dgr;3, such that &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2. The fiber exhibits a dispersion slope which is less than −1.0 ps/nm2/km over the wavelength range 1525 to 1565, a dispersion at 1550 which is less than −30 ps/mn/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is greater than 35 and preferably between 40 and 100.

Abstract: Disclosed is an optical circuit for filtering and frequency modulation of soliton signal pulses traveling over long spans of waveguide fiber. The circuit makes use of the filtering properties of a non-linear optical loop mirror (NOLM). The time difference between control pulses and signal pulses co-propagating in the NOLM is controlled to increase or decrease the centroid shift of the signal pulses. The signal and control pulse streams are derived from a single stream of soliton pulses. The NOLM serves to filter low power noise from the soliton signal pulses at the same time as it shifts the centroid frequency of the soliton signal pulses up or down. The circuit can be inserted at advantageous points along a waveguide fiber transmission line to allow propagation of solitons, without electronic regeneration, over line lengths of 100 km.

Abstract: The present invention relates to protecting optical devices, such as an optical fibre sensor connected in series with a cable, from a hostile environment, such as encountered when making measurements in oil and gas wells. A liquid can protect the optical device. Packaging an optical fibre sensor inside a capillary containing the liquid can provide this protection. The liquid can be liquid metal, gel, inks, grease or oil. The liquid metal can be gallium or indium, or an alloy that includes indium and/or gallium. The grease can contain lithium, molybdenum, or synthetics, or be synthetic grease. The liquid can contain other components such as a scavenger or getter for molecules and/or ions.

Abstract: An optical switch for processing an optical signal includes a refractive material having a first surface, a second surface, and a third surface. A first embodiment of the optical switch includes a lens having a planar surface that is coupled to the third surface of the refractive material, and a convex surface. A second embodiment of the optical switch includes a collimating lens, a first decollimating lens, and a second decollimating lens. The optical switch further includes a switchplate coupled to the second surface of the refractive material. The switchplate has a first position spaced apart from the second surface and a second position in proximal contact with the second surface.

Abstract: Disclosed is a hybrid waveguide structure, wherein a core or cladding has a hybrid section or “button” of a different optical property such as refractive index from the major portion of the core or cladding, respectively. The hybrid section can be made of a passive material or an electro-optic material. Methods of making a hybrid waveguide structure are also disclosed. These methods include rib-based methods and trench-based methods, and in either of these methods, a temporary filler is used in many instances to incorporate the hybrid section into the hybrid waveguide structure.

Abstract: An optical waveguide device comprising a free space region, suitably provided by a slab waveguide, having optical signal ports for coupling to input and output waveguide sections and an optical waveguide grating including an array of grating waveguides coupling the free space region to a reflector surface to provide a folded structure. Dielectric waveguide structures are preferred. The grating includes tapered optical waveguide sections laterally spaced and optically isolated from each other which extend from the free space region, with the grating waveguides continuing as extensions of the tapered waveguide sections. Each of the grating waveguides differs in length from a neighboring grating waveguide by a constant increment, preferably an optical path length increment.

Abstract: A communications cable is disclosed herein that includes an outer jacket, and either a core tube or at least one buffer tube. The core tube or at least one buffer tube includes a resin and high aspect ratio fillers that occupy a predetermined volume of the core tube or buffer tubes so as to impart crush resistance to the cable. Further, the core tube or buffer tube may include two layers, an outer layer and an inner layer, in which the outer layer includes both a resin and high aspect ratio fillers, and the inner layer includes the resin without the high aspect ratio fillers.

Abstract: A apparatus and method for testing portion of an optical fiber network from various remote stations without having to have optical testing equipment at those remote stations. The system and method utilize a series of routers that are located at the central office and the remote stations of an optical fiber network. The routers are interconnected through a common optical pathway that is part of the optical fiber network. Testing equipment is located at the central office of the optical fiber network. Optical testing signals and command signals are forwarded to the router at the central office. The router at the central office multiplexes the signals and forwards the signals as an optical transmission passing between the central office and a remote station. The router at the remote station removes the multiplexed signal from the optical transmission.

Abstract: A polarization insensitive photonic information router that can use polarization sensitive switches is disclosed. A photonic input image is polarization separated into two paths having mutually orthogonal fixed polarizations and complementary amplitude fluctuations in accordance with polarization fluctuations of the input image. Duplicate-acting switches, one for each fixed polarization, produce switched, polarized image pairs. These are connected so as to recombine energy from both polarization contributions in each of the switched outputs. Recombining can standardize output polarizations, or reproduce the input polarization fluctuations. Polarization stabilization can also be used before switching. Decoding packet data to operate the switch produces a polarization insensitive packet switching router.

Abstract: The present invention relates to an optical fiber transmission line comprising a structure for making it possible to maintain a desirable mean transmission characteristic as a whole regardless of the fluctuation in total length caused upon cutting end portions; and an optical cable including the same. The optical fiber transmission line according to the present invention comprises a main transmission line and first and second end sections connected, respectively, to both ends of the main transmission line. As a typical configuration, the main transmission line is constituted by a single-mode optical fiber and a dispersion-compensating optical fiber. At a wavelength of 1.55 &mgr;m, the single-mode optical fiber has a positive chromatic dispersion, and the dispersion-compensating optical fiber has a negative chromatic dispersion.