Abstract: A fiber optic, Faraday-effect current sensor (optical current transducer) which has improved temperature sensitivity due to compensation for temperature-induced variations of the Verdet constant. Fiber optic sensing coils can exhibit shifts in their bias angle due to a number of reasons, including physical rotation of the fibers, an apparent circular birefringence attributable to the sensing coil shape (Berry's phase), circular birefringence in the sensing fiber, or a DC magnetic field or current. The present invention takes advantage of the change in bias angle by identifying a preferred channel from the two sensing axes of the output fiber, based on the manner in which these axes respond to the change in bias angle. One of the axes will exhibit a change in sensitivity that exacerbates the change in sensitivity due to the Verdet constant, while the other channel will exhibit a change that complements, or compensates for, the change in sensitivity due to the Verdet constant.

Abstract: A passive electronic marker uses a plurality of ferrite cores to increase locating range, and the cores are attached in such a manner that a slight bend of the marker at a junction between the cores does not significantly affect the markers performance. Stable locating range and tuned frequency are achieved by controlling the air gap between the cores, using specially shaped ends or a sphere which is positioned between the cores. By selecting the appropriate geometry for the core ends and winding interconnections, the first order permeability across the air gap is held constant during bending of the marker.

Abstract: To provide a contact capable of reducing the crosstalk between adjacent contacts, and a terminal connector with such contacts, capable of constructing a high speed communication network. The contact 10 has a generally central base section 12, contact sections 14, 16 extending from the opposite ends of the base section 12 generally normal thereto, connecting sections 18, 20 obliquely extending generally in the same direction transverse to the contact sections 14, 16, for connecting the base section 12 with the contact sections 14, 16, respectively. One connecting section 18 has a first part 18a extending from one lengthwise end of the base section 12 generally normal thereto while maintaining a lateral distance from the contact section 14, a second part 18b extending from the contact section 14 in parallel thereto, and a third part 18c extending in the crossing direction to the surface of the contact section 14 to connect the first part 18a to the second part 18b.

Abstract: A fiber optic connector comprising a plug and a receptacle uses the spring force supplied by bowing of the plug fiber to maintain a continuous compressive load at the fiber joint located in a fiber-alignment groove. The plug has a holder for securing the plug fiber and a shroud which snaps onto the holder with the plug fiber extending generally straight inside the shroud. The shroud has a slot providing access to the terminal portion of the plug fiber, and a sliding door which selectively covers the slot. The receptacle includes a housing and another fiber holder for securing the receptacle fiber, with a projection or finger attached to the receptacle fiber holder, the projection having the fiber-alignment groove. The finger is oriented within the receptacle housing such that, when the plug is inserted into the receptacle, the finger extends through the slot in the shroud at an oblique angle with respect to the plug axis.

Abstract: A closure with improved cable strain relief, having a body with a closed end and an open end, a tubular base having first and second ends with the open end of the body releasably secured to the first end of the base, and a strain relief member attached to the second end of the base. The strain relief member is composed entirely of non-metallic components, and includes a plate having cutouts therein forming cable ports, each of the cutouts having a wall and an inner surface along the wall, there being a plurality of gripping teeth along each inner surface, and each wall having at least one channel therein with entry and exit slots. A cable tie securing a cable in one of the cutouts is threaded through the channel, extending out the entry and exit slots. The plate advantageously has a plurality of outer surfaces shaped to fit snugly with an inner surface of the second end of the base, and flanges located at each outer surface for attachment to an edge of the second end of the base.

Abstract: A cover assembly including a crushable support (100) for supporting an elastomeric tube is described, the elastomeric tube being recoverable to at least a part of its original size and shape after collapse of said support, comprising: a plurality of substantially longitudinally extending portions (12); a plurality of connection portions (14), each longitudinally extending portion (12) being connected to, and spaced apart from neighboring longitudinally extending portions (12) by at least one of said connection portions (14) to form a rigid structure; and said at least one of said connection portions (14) including at least one frangible zone (16).

Abstract: A Faraday effect current sensor uses a plurality of concatenated field sensors, with a single light source and a single detector. At least two Faraday effect sensing elements (single mode sensing fibers) are used, preferably at least three, the sensing elements being interconnected by fusion spliced, polarizing fibers. The sensing fibers may be oriented generally straight, and arranged to form a regular polygon, e.g., an equilateral triangle for a three-element sensor. The locations of the splices between the sensing fibers and the polarizing fibers may further be advantageously arranged such that the sensing fibers form a substantially closed path which may be placed about the current-carrying conductor. The linearity of the sensor response may be improved by selecting an appropriate value of the bias angle of each sensing element, optimally equal to arctan?1/.sqroot.(2n-1)! where n is the number of sensing elements.

Abstract: A device for interconnecting the bare ends of two or more optical fibers uses a common receptacle having a fiber clamping element therein and camming surfaces for actuating the element, and at least one plug having a camming finger for engaging one of the camming surfaces. The camming surfaces are located such that, when only one of the camming surfaces is actuated, the clamping element rocks to a side of the pocket opposite the one camming surface and remains in the open state, but when both of the camming surfaces are actuated, the clamping element is forced to the closed state. The plug includes a fiber protector free to slide within the plug housing, substantially enclosing the bare end of the fiber when the plug housing is removed from the receptacle, but retracting when the plug housing is inserted into the receptacle to direct the bare end of the fiber toward said guide tube.

Abstract: A method and system for activating and deactivating a fiber optic splice within an optical fiber distribution frame while the fiber optic splice is releasably retained within a connector tray within the optical fiber distribution frame. The connector tray preferably includes multiple slots for supporting a number of mechanically activatable fiber optic splices which each include a jacket and a cap which is retained in a first intermediate position within the jacket while the fiber optic splice is deactivated and in a second fully inserted position within the jacket while the fiber optic splice is activated. An activator tool is provided which includes a stop member and slidably mounted pivot member which may be utilized to engage the fiber optic splice jacket and urge the cap into the fully inserted position in response to relative movement between the pivot member and the stop member in order to activate the fiber optic splice while the fiber optic splice is retained within the connector tray.

Abstract: A device for interconnecting the bare ends of two or more optical fibers uses a common receptacle having a fiber clamping element therein and camming surfaces for actuating the element, and at least one plug having a camming finger for engaging one of the camming surfaces. The camming surfaces are located such that, when only one of the camming surfaces is actuated, the clamping element rocks to a side of the pocket opposite the one camming surface and remains in the open state, but when both of the camming surfaces are actuated, the clamping element is forced to the closed state. The plug includes a fiber protector free to slide within the plug housing, substantially enclosing the bare end of the fiber when the plug housing is removed from the receptacle, but retracting when the plug housing is inserted into the receptacle to direct the bare end of the fiber toward said guide tube.

Abstract: An optical module for interconnecting two or more optical fibers has a microreplicated waveguide element which is integrally formed on the same substrate with a splice element. In one embodiment, the module has three plates, a bottom plate, a cover plate, and a top plate, all contained within a common housing. The bottom plate has fiber-receiving grooves and fiber alignment grooves at its ends, the fiber alignment grooves being aligned with waveguide channels formed on the central portion of the bottom plate. The cover plate is used when forming the cores of the waveguide channels, to force residual curable, waveguide material into flow channels adjacent the waveguide channels, and this material, when cured, adheres the bottom and cover plates together. The top plate is used to clamp fibers which are held in the fiber alignment grooves, with the center of the fibers aligned with the core of the waveguide channels.

Abstract: A sleeve for protecting and reinforcing a fusion splice of two or more optical fibers. The fusion splice protector includes a heat-shrinkable sleeve adapted to surround the fusion splice and adjacent portions of the fused optical fibers, a stress-relieving support element adjacent the fusion splice, and a hot-melt adhesive contained within the sleeve for retaining the support element adjacent a longitudinal section of the sleeve. The support element is designed to impart varying elasticity along a length of the sleeve such that the fusion splice protector is more rigid at the central portion of the sleeve member than at its ends. This may advantageously be achieved by providing a support element having a cross-sectional profile which varies along the length of the sleeve. The support element is preferably constructed of a polymer or polymer blend, most preferably one having a coefficient of thermal expansion which is approximately equal to the coefficient of thermal expansion of the optical fibers.

Abstract: A fiber optic subassembly for a Faraday-effect current sensor has an optical sensing fiber supported by a tubular holder in a square or rectangular configuration, with the three of the four corners thereof designed with bends which have a net zero bend-induced birefringence. The bends are formed by providing two loops which have effective angles of about 90.degree., the two loops lying in orthogonal planes, such that the fast axis of birefringence in the first loop is parallel to the slow axis of birefringence in the second loop, and the slow axis of birefringence in the first loop is parallel to the fast axis of birefringence in the second loop. In this manner, retardance accumulated in the first loop is offset by retardance accumulated in the second loop. If the loops are substantially identical, the offsetting of the retardance is effectively complete such that the bend exhibits negligible bend-induced birefringence.

Abstract: An H-field electromagnetic heating system for fusion bonding, particularly useful in the sealing of telecommunications cables and closures, comprises a composite bonding material having a bonding matrix and susceptors, the susceptors being magnetically reactive at a frequency above 50 MHz, and an applicator for applying radiant electromagnetic energy to the composite bonding material, at a frequency above 50 MHz (preferably 75-500 MHz). The applicator may take the form of a quarter-wave resonator having an inner conductor and an outer conductor which at least partially surrounds the inner conductor, the two conductors being shorted at a common end. The material to be heated is placed between the conductors. The inner conductor may include a resonator tube which is capacitively coupled to the power supply by a capacitive probe connected to the center conductor of a coaxial connector.

Abstract: A device for interconnecting the bare ends of two or more optical fibers uses a common receptacle having a fiber clamping element therein and camming surfaces for actuating the element, and at least one plug having a camming finger for engaging one of the camming surfaces. The camming surfaces are located such that, when only one of the camming surfaces is actuated, the clamping element rocks to a side of the pocket opposite the one camming surface and remains in the open state, but when both of the camming surfaces are actuated, the clamping element is forced to the closed state. The plug includes a fiber protector free to slide within the plug housing, substantially enclosing the bare end of the fiber when the plug housing is removed from the receptacle, but retracting when the plug housing is inserted into the receptacle to direct the bare end of the fiber toward said guide tube.

Abstract: The method and system of the present invention provide an improved "F" port interface connector is provided having increased ampacity and greater reliability. The "F" port interface connector includes a generally cylindrical port having an insulative dielectric sleeve mounted therein. An electrically conductive spring contact is mounted within the dielectric sleeve. The spring contact includes two elongate elastically bendable conductive leaves which are mounted in a slightly mutually skewed relationship and each leaf includes a medial mating surface and a cam surface at one end.

Abstract: Silica tubes and sleeves are used to protect fusion splices between the ends of the fiber coil and polarizing fibers. Use of silica for most of the subassembly components matches the coefficients of thermal expansion of the subassembly to that of the fiber coil, and also allows the coil to be annealed at extremely high temperatures. Annealing yields fiber coils of lowered birefringence, particularly when used with spun fibers. Ferrules are used to adjust the angular orientation of the fibers with respect to their planes of polarization.

Abstract: A splice member for splicing ends of optical fibers is provided with clips to restrict torsional stress from being applied to the ends of the cables held in the splice element. A tool is used to secure the splicing member onto the cables and it operates to sequentially actuate the splicing element to grip and align the fiber ends and actuates the clamps onto the fiber to restrict the torsional stress on the fiber ends.

Abstract: A shield bond strain connector for a cable which has strength members therein, such as a fiber optic telecommunications cable having an outer jacket surrounding the strength members and optical fibers, the connector having (i) an inner clamping element positioned against an inner surface of the cable jacket, with a first mounting bolt attached to the inner clamping element, and a prong formed along an end of the inner clamping element, (ii) an outer clamping element positioned against an outer surface of the cable jacket, having a hole therein receiving the first mounting bolt, and being forcibly urged against the cable jacket toward the inner clamping element, (iii) a clamping plate having a second mounting bolt thereon, and (iv) a shield bond extension element having first, second and third holes therein, the first hole receiving the first mounting bolt, the second hole receiving the prong, affixing the extension element to the inner and outer clamping elements, while the third hole receives the second moun