Abstract: The specification describes a connector for joining optical elements, especially optical fibers. The connector is a sleeve made of a Simple Shaped Memory Polymer (SSMP) into which the optical fiber is inserted and the sleeve heated to collapse the sleeve around the optical fiber. The SSMP materials are not crosslinked and can be manufactured by a variety of techniques including extrusion. Various methods for forming the bore of the connector and expanding the size of the bore from the memory state to the metastable state are described.

Abstract: Embodiments of the invention include an optical communications system including a multimode optical fiber having improved overfill-launch bandwidth performance without disturbing existing laser-launch bandwidth performance. The multimode optical fiber has a characteristic differential mode delay with a first portion associated with lower order modes that behaves conventionally and a second portion associated with higher order modes that deviates from conventional behavior in a way that improves overfill-launch bandwidth performance at one operating window without adversely impacting the laser-launch bandwidth performance at the same and other operating windows. Multimode optical fibers conventionally optimized for operation at 850 nm are configured in such a way that their characteristic differential mode delay, at 1300 nm, initially increases in a conventional manner and then flattens out to approximately zero at the higher order modes.

Abstract: The use of silica powders having large particle sizes in making sol-gel silica bodies has been found to have important advantages. Among these are higher gel strength, higher silica loading, more rapid aging and drying of the gel, a reduction in the amount of organic additives leading to reduced process time required for organic burn-off, and easier removal of contaminant particles due to their larger size. It was also discovered that spherical particle morphology contributes to the improved properties.

Abstract: An extrusion system for producing a desired extrusion profile on a continuously moving work piece has a die containing two or more pressurized fluid extrusion cells therein, through which the work piece passes. Fluid under pressure id directed against the work piece to shape it without physical contact between the die and the work piece. The individual extrusion cells are configured to produce the desired profile, which is monitored by a non-contact metering member which applies signals to a processing unit which, in turn, applies correction signals to a pressured fluid supply module to control the pressurized fluid supply to each of the extrusion cells.

Abstract: An apparatus for making optical fiber circuits including a mechanism that supplies optical fibers, a rotary support for supporting an adhesive-coated substrate in such a way that the substrate is in contact with the optical fiber, and a linear tracking arm that is equipped with a fiber routing and fixing head that routes and fixes the fibers into a shape on the substrate. Further included is a method for making optical fiber circuits including the steps of mounting a substrate on a rotary support and layering at least one layer of optical fibers from an optical fiber supply mechanism on the substrate in a shape such as a spiral by using the rotary range of motion of the substrate support and a linear range of motion of a tracking arm.

Abstract: Apparatus for shaping a selected end region and the opening at a selected end of a hollow cylindrical glass tube includes a support member for holding and rotating the tube in a controlled manner and a heat source for supplying sufficient heat to the selected end region of the tube to place it in a malleable state. The apparatus also includes an actuatable mechanical holding means for holding a multi piece mold and for selectively applying the mold to the selected end region of the tube, when the tube is rendered malleable, for shaping the selected end region of the tube including its rim and for controlling the inner diameter of the tube throughout its end region. In one embodiment the apparatus includes a temperature sensor for controlling the operation of the mechanical holding means and the action of the heat source and a micro-controller for automatically activating the application and retraction of the mold.

Abstract: Techniques and systems are described for splicing together first and second optical fibers. A thermal treatment station is described, having a chassis, a fiber holding block for holding a pair of optical fibers that have been spliced together at a splice point, the fiber holding block including a cutaway portion exposing the splice point, and a torch, the fiber holding block and the torch being mounted to the chassis such that the positions of the splice point and the torch can be adjusted with respect to each other so that the splice point lies in the flame. A technique for splicing together two optical fibers is further described, in which the optical fibers are first spliced together using a fusion splicer and then thermally treated by positioning the splice point in a flame while monitoring splice loss.

Abstract: An assembly for fabricating an optical fiber ribbon from optical fibers that extend in a longitudinal direction includes a spacing device. The spacing device is operative to vary the spacing between the optical fibers in the lateral direction. The spacing device can be a rotatable cylinder having diverging external grooves that respectively receive the optical fibers. A bonding device applies bonding material to the optical fibers to form an optical fiber ribbon, after the spacing between the optical fibers has been varied by the spacing device. In accordance with a method of manufacturing an optical fiber ribbon, optical fibers that extend in a longitudinal are advanced along travel paths defined by the grooves of the spacing guide. The travel paths diverge from one another in a lateral direction that is generally perpendicular to the longitudinal direction so that as the optical fibers are advanced the optical fibers become further spaced apart from one another in the lateral direction.

Abstract: The location and type of equipment shelf installed in an optical fiber distribution frame is detected and transmitted to a software management system automatically. A plurality of photo transceivers, arrayed on the frame, detects encoded indicia on each shelf. The coded information is inventoried into a database and displayed in a virtual graphical representation of the frame.

Abstract: A silica-based core rod is traversed by a heat source along its longitudinal axis, to provide heated, softened regions. During the traverse, compressive or tensile movements are provided along the rod's longitudinal axis, these movements inducing, respectively, increases or decreases in the core diameter at the softened regions. By providing selective core diameter increases and/or decreases across the entire length of the core rod, a desired core diameter profile is attained. It is possible to attain a substantially uniform core diameter, or a varying core diameter profile that provides particular properties, such as systematically varying dispersion. In addition, due to the ability to increase core diameter and core rod diameter in a controlled manner, it is possible to make larger core rods, and in turn larger fiber preforms, than presently possible.

Abstract: An optical fiber connector adapter has a sensing mechanism for determining when the adapter has a connector plug therein and when the adapter is vacant or empty. The sensing mechanism creates an indication of the state of the adapter which is transmitted to a control circuit. The control circuit responds to the indication by activating or deactivating a laser, for example, which applies optical energy to the adapter. The laser is deactivated when the adapter has no connector plug therein and is activated when there is a connector plug in place in the adapter. In two of the embodiments of the invention, the sensing mechanism signals the impending insertion or withdrawal of the connector plug relative to the adapter.

Abstract: A dust cap 100 for an optical connector 200 protects an optical fiber 21 from abrasion, dust and debris. The dust cap is a box-like housing having front and back ends and side walls that define a cavity 13. The back end 12 has an opening into the cavity that is shaped to receive the optical connector, and a retaining feature 14 is molded into the cavity for interlocking with a mating feature 24 on the optical connector so that the dust cap will not become detached from the connector during vigorous handling. The optical fiber is generally supported within the connector by a ferrule 22, and the dust cap includes a tubular member 15 that is shaped to receive and enclose a front portion of the ferrule for improved protection. The distal end 16 of the tubular member is closed and projects outwardly from the front end 11 of the dust cap. The proximal end 17 of the tubular member projects inwardly and has an opening that is shaped to receive the ferrule.

Abstract: An optical cable tracing system is constructed using an optical/electrical (hybrid) cable 10 containing both optical and electrical transmission media. This cable provides desirably high bandwidth via optical fibers 15 while connection accuracy is provided via electrical wires 13, which are used to operate indicator lights 941 at one or both ends of the cable. A hybrid plug connector 300 terminates the cable at each end and includes a dielectric housing 20, 30 that encloses the optical fiber (glass or plastic), which extends through a front opening 21 in the housing. A single cantilever latch 22 is mounted on a top-side of the housing that is adapted to engage a mating jack receptacle 440 in a locking relationship. A conductor-holding apparatus is molded into the bottom side of the housing where it holds a number of insulated electrical conductors and metallic blade terminals 36 that pierce the insulation and make electrical contact with each of the conductors.

Abstract: An optical transmission line with reduced splice loss, and methods for fabricating an optical transmission line with reduced splice loss, are described. In one described method, a length of dispersion-compensating fiber, or other suitable first transmission fiber, is spliced to a first end of a length of a bridge fiber. The splice is heated to a maximum temperature to cause a measurable reduction in splice loss. The temperature of the splice is then ramped down to room temperature, such that the reduction in splice loss is maintained. A second end of the bridge fiber is then spliced to a length of a second transmission fiber. Further described is a technique for determining the maximum temperature for heating the splice between the first transmission fiber and the bridge fiber.

Abstract: Signals propagating in a buffered optical fiber within, for example, an optical jumper cable, are attenuated by clamping a grating along an axial length of buffer material on the fiber. A fundamental resonant coupling or grating period that would induce attenuation of light signals in the fiber in the absence of buffer material, is determined. The grating clamped on the fiber has a periodicity that is N times the determined fundamental period, wherein N is a positive integer.

Abstract: A mold for shaping the end region and the opening at a selected end of a first, hollow, generally cylindrical, glass tube to enable a second tube, of smaller diameter than the first tube, to be inserted snuggly a first distance within the selected end of the first tube resulting in the two tubes nesting and being self-centered. The mold includes two complementary elongated side pieces having inner side surfaces for, when joined, encircling the periphery of the first tube along a given portion of its selected end region, and an end cap with a cylindrical stub for insertion within the opening of the first tube at its selected end.

Abstract: The refractive index profile of a multimode optical preform, fabricated by MCVD for example, is modified in the longitudinal direction by removing selected amounts of core material from the wall of a central hole through the preform prior to collapse. The amount of core material to be removed is determined by measuring the refractive index profiles of optical fibers drawn from a number of precursor preforms at various locations along the length of the drawn fibers, averaging their profiles, and then comparing those averages with a desired profile. The refractive index profile is indirectly measured by bandwidth measurements, which are related to the alpha value a selected parameter (e.g., bandwidth) at various locations along the length of a fiber drawn from a previously fabricated preform. This parameter is then compared with desired values of that parameter at the various locations, and the differences are used to calculate the amount of core material that needs to be removed.

Abstract: An improved process for extruding plastic optical fiber without the need to prepare a preform is provided. Specifically, it was discovered that conventional extrusion techniques, e.g., screw extruders, tended to introduce an undesirable amount of particulate contaminants which increased the loss of the drawn fiber. To overcome this problem, the invention substantially reduces the number of mechanical interactions that contribute to such contamination. The process of the invention does so by using fluid pressure, instead of, e.g., screw extruders, to induce polymer flow. The process also controls the flow characteristics of the polymer, or halts the flow altogether, without mechanical controls. Specifically, the temperature of the sections through which the polymer flows is controllably adjusted, such that it is possible to bring the polymer to a desired flow rate or even to a solid state to provide a plug.

Abstract: A universal modular optical fiber buildout for use in coupling a first optical fiber cable to a second optical fiber cable is disclosed. The universal buildout includes a buildout base formed about a longitudinal axis, and a buildout cap for being received within the base. The buildout base is constructed and arranged to receive the first optical fiber cable at a first end thereof, and any one of a plurality of the different types of buildout caps at the second end thereof. In similar fashion, the buildout cap is constructed and arranged to receive the second optical fiber cable at a first end thereof, and is constructed and arranged to be received within a second end of any one of a plurality of the different types of buildout bases.

Abstract: A system and method for determining the optical loss characteristics of optical fibers in an optical fiber network. An optical transmission module is provided. The optical transmission module produces a light signal and an electrical signal that contains data regarding the characteristics of the light signal being generated. The light signal output of the optical transmitter module is connected to the input of a calibrated optical switch. The outputs of the optical switch are connected to the optical fibers that are to be tested. At the opposite ends of the optical fibers, a second optical switch is provided. The second optical switch connects the various optical fibers to a monitor module. The monitor module detects the light signal transmitted by the optical transmitter module through the various optical fibers. The monitor module converts the received light signal into a corresponding electrical signal. A systems controller is coupled to both the optical transmitter module and the monitor module.