Abstract: This intermittent connection-type optical fiber tape core is configured in a manner such that in a state where a plurality of optical fiber cores are arranged in parallel in a direction perpendicular to the lengthwise direction of said plurality of optical fiber cores, some or all of the intervals between the plurality of optical fiber cores are intermittently provided in the lengthwise direction with connected sections where the intervals between adjacent optical fiber cores are connected and non-connected sections where the intervals between adjacent optical fiber cores are not connected. The outer diameter of each of the plurality of optical fiber cores is 160-220 ?m, inclusive. The catenary amount of the tip end of the intermittent connection-type optical fiber tape core projecting from the held location is 0.1-2 mm, inclusive, in a given state.

Abstract: A multicore fiber includes: a cladding; a center core at a center of the cladding; and seven or more outer cores disposed at rotationally asymmetric positions on a circumference centered at the center of the cladding. Angles formed by adjacent ones of lines connecting the center core and respective ones of the outer cores are all 60° or less.

Abstract: A rollable optical fiber ribbon utilizing low attenuation, bend insensitive fibers and cables incorporating such rollable ribbons are provided. The optical fibers are supported by a ribbon body, and the ribbon body is formed from a flexible material such that the optical fibers are reversibly movable from an unrolled position to a rolled position. The optical fibers have a large mode filed diameter, such as ?9 microns at 1310 nm facilitating low attenuation splicing/connectorization. The optical fibers are also highly bend insensitive, such as having a macrobend loss of ?0.5 dB/turn at 1550 nm for a mandrel diameter of 15 mm.

Abstract: An optical fiber cable includes a central tube having a first inner and a first outer surface. The first inner surface defines a bore along a longitudinal axis of the cable. Optical fibers are disposed within the bore of the central tube. A cable jacket is disposed around the central tube. The cable jacket has a second inner and a second outer surface defining a first thickness. A skin layer is disposed around the cable jacket. The skin layer has a third inner and a third outer surface defining a second thickness that is 100 ?m or less. The cable jacket material is different from the skin layer material, and the third outer surface defines the outermost surface of the optical fiber cable. Access sections made of the second material extend from the skin layer into the first thickness of the cable jacket.

Abstract: The invention generally relates to optical fibers, and, more particularly, to hollow-core optical fibers and cables for use in high-speed data transmission, including transmission of telecommunications data, and methods of manufacturing such hollow-core optical fibers and cables.

Abstract: A buffer tube for an optical fiber cable provided by the present disclosure includes an optical fiber ribbon stack, a first layer, a second layer, an optical fiber cable, a central strength member, a plurality of buffer tubes, a water blocking layer, and a sheath and plurality of rip cords. The first layer is an inner layer of the buffer tube. The first layer is made of a soft material. The soft material of the first layer is one of low smoke zero halogen, thermoplastic elastomers and thermoplastic polyurethane. The second layer is an outer layer of the buffer tube. The second layer surrounds the first layer. The second layer is made of a hard material. The hard material of the second layer is one of polypropylene, polybutylene terephthalate, and nylon.

Abstract: The present disclosure relates to method for underground installation of a pre-ducted optical fiber cable assembly. The method includes a first step of drilling a first pilot bore from a second manhole to a first manhole. In addition, the method includes a second step of pulling the pre-ducted optical fiber cable assembly. Further, the method includes a third step of drilling a second pilot bore from a third manhole to the second manhole. Furthermore, the method includes a fourth step of pulling the pre-ducted optical fiber cable assembly from the second manhole to the third manhole. Moreover, the method of underground installation of the pre-ducted optical fiber cable assembly eliminates the need for blowing the pre-ducted optical fiber cable assembly with a cable blowing machine.

Abstract: Disclosed is an armored fire resistant fiber optic cable including a core comprising a central strength member, and a plurality of buffer tubes arranged around said central strength member, each buffer tube containing a plurality of optical fibers; a first mica layer arranged around the core; an inner sheath surrounding the first mica layer; a metal wire armor surrounding the inner sheath; and an outer sheath surrounding and in direct contact with the metal wire armor, wherein a second mica layer surrounds the inner sheath and the metal wire armor surrounds the second mica layer.

Abstract: A method of forming an imaging fibre apparatus comprises arranging rods to form a plurality of stacks each comprising a respective plurality of rods, wherein: for each stack, the respective plurality of rods comprises rods having different core sizes, the rods of different core sizes being arranged in a selected arrangement, and the rods of different core sizes being arranged such that each stack has a respective selected shape; wherein the selected shape or shapes are such that the stacks stack together in a desired arrangement; the method further comprising: drawing each of the plurality of stacks; stacking together the plurality of drawn stacks together in the desired arrangement to form a further stack; drawing the further stack; and using the drawn further stack to form an imaging fibre apparatus, wherein the selected arrangement of the rods in each stack and the selected shape or shapes of the stacks are such that the further stack comprises a repeating pattern of rods of different core sizes.

Abstract: The present invention is directed to water-swellable, radiation curable compositions suitable for use in coating water-blocking fibers, such as optical fibers. The present invention is further directed to fibers, including optical fibers, which are coated with water-swellable exterior coatings that are configured to buckle and detach from the associated fiber to facilitate superior performance in longitudinal water-blocking testing. Also claimed and described are methods of applying such water-swellable coatings to optical fiber coatings. Further claimed and described are buffered bundles of fibers including at least one optical fiber that is coated with a water-swellable, radiation curable coating to ensure superior longitudinal water blocking performance.

Abstract: The present disclosure provides a formfitting loose tube for optic cables. The formfitting loose tube includes a loose tube wall. The loose tube wall includes first sides, second sides, a plurality of deformation induction tabs and a plurality of fiber optics stacked together having a shape form. The plurality of deformation induction tabs includes curving sections. The curving sections intersect the first sides and the second sides at intersections. The first sides and the second sides of the loose tub wall are configured to fit the shape form of the plurality of fiber optics stacked together. The plurality of deformation induction tabs induces elastic deformation of the loose tube wall under external stress.

Abstract: In one embodiment, a fiber optic cable comprises a core comprising a central strength member and a plurality of buffer tubes arranged around the central strength member, where each buffer tube includes a plurality of optical fibers. The fiber optic cable includes a mica layer arranged around the core, a glass yarn layer surrounding and in direct contact with the mica layer, an inner sheath surrounding and in direct contact with the glass yarn layer, a metal armor surrounding the inner sheath; and an outer sheath surrounding and in direct contact with the metal armor. The central strength member comprises a hydroxide-containing flame retardant polymeric material, and the plurality of buffer tubes contain a water-blocking filling material comprising a silicone gel, where the silicone gel has a drop point of at least 200° C., and where the fiber optical cable is configured to be fire resistant.

Abstract: The present invention relates to padded optic fiber ribbons for dry optic fiber cables. The dry padded optic fiber ribbons include a plurality of optic fiber ribbons stacked on top of each other having a cross-sectionally rectangular shape. In addition, the dry padded optic fiber ribbons include a plurality of dry paddings. Each dry padding of the plurality of dry paddings has an inner side and an outer side. Further, the dry padded optic fiber ribbons include at least one tape wrapping around the plurality of dry paddings.

Abstract: A method of producing an optical-fiber ribbon includes applying bonding material to a major surface of an optical-fiber assembly via a dispenser that is revolving around a central axis to bond adjacent optical fibers in the optical-fiber assembly. The method, which facilitates faster line speeds, achieves an optical-fiber ribbon with an adhesive bead that forms a distorted sinusoidal pattern substantially across the width of the optical-fiber assembly.

Abstract: The purpose of the present invention is to allow a water stop performance between electric wires to be maintained as much as possible even when the electric wires are bent. A water stop structure for an electric wire bundle includes an electric wire bundle in which a plurality of electric wires are bundled together, a filler with which gaps between the plurality of electric wires are filled while maintaining fluidity and viscosity in at least a portion of an extension direction of the electric wire bundle, and a covering body covering a circumference of the portion of the electric wire bundle filled with the filler.

Abstract: A water-cooled package of a fiber-optic transport head comprising a delivery optical fiber (DOF), an interface optics, an end plug, an optically transparent tube, a tube holder comprising multiple broken cuts, and a housing operates for delivering a high-power laser light from DOF to free space. The interface optics is fusion-spiced with a section of DOF with a cladding exposed whereas the section of DOF with the cladding exposed is enclosed in a bore of the optically transparent tube, working together as a cladding mode stripper. The multiple broken cuts allow optical energy from the cladding mode stripper to randomly launch the housing in a way that the optical energy is uniformly distributed, thereby no localized hot spots possibly existed. The housing comprises a set of internal threads comprising a helix angle and a tooth height. The set of internal threads facilitates thermal dispersion, effectively reducing temperature on the housing.

Abstract: Techniques are disclosed for systems and methods to provide a magnetic materials additive manufacturing system (MMAMS) configured to form compact magnetic structures and/or devices. A MMAMS includes a controller and one or more dispensers configured to dispense magnetic material matrix in a high resolution pattern in order to form the compact magnetic structures and/or devices. The MMAMS receives a magnetic device design including a magnetic structure to be formed from a magnetic material matrix, where the magnetic material matrix is configured to be used in the MMAMS. The MMAMS receives magnetic material matrix and dispenses the magnetic material matrix to form the magnetic structure.

Abstract: A flooding composition comprising in weight percent (wt %) based on the weight of the composition: (A) 10-80 wt % of a first component comprising a polyolefin elastomer; and (B) 20-90 wt % of a second component comprising a bio-based fluid.

Abstract: Embodiments of an optical fiber cable are provided. The optical fiber cable includes at least one optical fiber, a buffer tube surrounding the at least one optical fiber, and at least one tensile element wound around the buffer tube. The at least one tensile element has a laylength of at least 200 mm. The optical fiber cable also includes an exterior jacket surrounding the tensile element. The exterior jacket is made up of at least one polyolefin, at least one thermoplastic elastomer, and at least one high aspect ratio inorganic filler. Further, the exterior jacket has an averaged coefficient of thermal expansion of no more than 120(10?6) m/mK.

Abstract: The present disclosure provides an optical fiber cable. The optical fiber cable includes a central strength member. The central strength member lies substantially along a longitudinal axis of the optical fiber cable. The optical fiber cable includes at least one buffer tube. The at least one buffer tube is stranded helically around the central strength member. Each of the at least one buffer tube encapsulates at least one optical fiber. The optical fiber cable includes a first layer. The first layer circumferentially surrounds a core of the optical fiber cable. The optical fiber cable includes a second layer. The second layer is formed of high density polyethylene. The optical fiber cable includes at least one set of water swellable yarn and a plurality of ripcords.

Abstract: The present disclosure relates to a fiber optic network configuration having an optical network terminal located at a subscriber location. The fiber optic network configuration also includes a drop terminal located outside the subscriber location and a wireless transceiver located outside the subscriber location. The fiber optic network further includes a cabling arrangement including a first signal line that extends from the drop terminal to the optical network terminal, a second signal line that extends from the optical network terminal to the wireless transceiver, and a power line that extends from the optical network terminal to the wireless transceiver.

Abstract: A fiber optic cable assembly includes an elongate housing, a signal fiber placed inside the housing and extending longitudinally, and a plurality of sensing fibers placed inside the housing and extending longitudinally. The plurality of sensing fibers is placed around the signal fiber. Each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency. The signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers.

Abstract: A fiber optic cable assembly includes an elongate housing, a signal fiber placed inside the housing and extending longitudinally, and a plurality of sensing fibers placed inside the housing and extending longitudinally. The plurality of sensing fibers is placed around the signal fiber. Each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency. The signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers.

Abstract: A flame retardant and/or crush-resistant optical cable is provided. The cable includes a plurality of optical fibers and an inner jacket surrounding the plurality of optical fibers. The inner jacket includes an inner layer and an outer layer. The cable includes an armor layer surrounding the inner jacket. The cable includes an outer jacket surrounding the armor layer. The inner layer of the inner jacket, the outer layer of the inner jacket and/or the outer jacket are formed from one or more different material providing different properties to the cable. For example, the outer jacket may be formed from a flame-retardant, zero-halogen polymer material, the inner layer of the inner jacket may be chemically resistant to inorganic material, and the outer layer of the inner jacket may be chemically resistant to organic material.

Abstract: Fiber optic cables suitable for use in downhole applications, with one or more features for inhibiting flow of any fluid breaching an armor layer of the optical cable are provided. By preventing, or at least impeding, fluid flow along the cable length, any breaching fluid may be confined to a small region of the cable, which may significantly reduce the deleterious effects (e.g., hydrogen darkening) of an armor layer breach. One example optical cable generally includes one or more optical fibers, an inner tube surrounding the one or more optical fibers, an outer tube surrounding the inner tube, and one or more polymer sealing features disposed in an annulus between the outer tube and the inner tube and bonded to at least one of the inner tube or the outer tube to prevent fluid flow in the annulus along at least a portion of a length of the optical cable.

Abstract: A gesture sensing device includes a multiple segmented photo sensor and a control circuit for processing sensed voltages output from the sensor. The control circuit processes the sensed voltage signals to determine target motion relative to the segmented photo sensor. The control circuit includes an algorithm configured to calculate one of more differential analog signals using the sensed voltage signals output from the segmented photo sensors. A vector is determined according to the calculated differential analog signals, the vector is used to determine a direction and/or velocity of the target motion.

Abstract: A cable, which extends in a longitudinal direction, has a cable core and a cable jacket. The cable jacket is extruded around the cable core. The cable is distinguished by the fact that the cable jacket has a plurality of chambers and, overall, is designed, in particular, in the manner of a hollow profile, and by the fact that a functional material different from the material of the cable jacket is introduced within at least one of the chambers. The functional material is preferably a flame proofing agent, but numerous other materials and, in general, functional elements are also conceivable. We further describe a method for producing the cable.

Abstract: A fiber optic cable assembly includes an elongate housing, a signal fiber placed inside the housing and extending longitudinally, and a plurality of sensing fibers placed inside the housing and extending longitudinally. The plurality of sensing fibers is placed around the signal fiber. Each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency. The signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers.

Abstract: The present disclosure provides an optical fiber cable. The optical fiber cable includes a central strength member. The central strength member lies substantially along a longitudinal axis of the optical fiber cable. In addition, the optical fiber cable includes a first layer. The first layer includes a plurality of water swellable yarns. Further, the optical fiber cable includes a plurality buffer tubes. Each of the plurality of buffer tubes includes a plurality of optical fiber. Moreover, the optical fiber cable includes a second layer of a pair of binder yarns. Further, the optical fiber cable includes a third layer. The third layer is formed of a plurality of water swellable yarns. The optical fiber cable includes a fourth layer. The fourth layer is a sheath layer.

Abstract: A fiber optic cable assembly includes an elongate housing, a plurality of fiber optic cables placed inside the housing and extending longitudinally, and acoustic isolating material placed inside the housing and extending longitudinally. The acoustic isolating material includes a plurality of outwardly radially extending arms extending from a center of the housing towards a circumference of the housing. The plurality of arms divides a space inside the housing into a plurality of acoustically isolated sections. Each acoustically isolated section extends longitudinally. Each acoustically isolated section includes at least one of the plurality of fiber optic cables. Each acoustically isolated section is acoustically insulated from remaining sections of the plurality of acoustically isolated sections. A surface of the acoustic isolating material of each acoustically isolated section is covered by acoustic reflective material.

Abstract: A fiber optic cable includes core elements wound in a pattern of stranding, the core elements comprising tubes surrounding optical fibers. The fiber optic cable further includes an binder film surrounding the stranded core elements. The binder film is continuous peripherally around the core elements, forming a continuous closed loop when viewed in cross-section, and continuous lengthwise along a length of the cable that is at least a meter. Further, the binder film is in radial tension and opposes outwardly transverse deflection of the core elements.

Abstract: A crush resistant, kink resistant optical cable including crush resistant, kink resistant optical fiber buffer tubes and systems and method for making the same are provided. The buffer tubes include a depression pattern formed along the outer surface of the buffer tube. The depression pattern provides areas of decreased thickness in the buffer tube facilitating flexibility and kink resistance. The system and method relates to laser ablation for forming the depression pattern in the buffer tube.

Abstract: An optical cable is provided. The optical cable includes a tubular, elongate body having an inner surface defining a cavity extending between first and second ends of the elongate body and an optical transmission element located with the cavity. The optical cable includes a coupling or bonding structure non-permanently and non-rigidly joining the outer surface of the optical transmission element to the elongate body at a plurality of periodic contact zones such that relative movement between the optical transmission element and the elongate body is resisted.

Abstract: A device for rearranging optical fibers has a proximal and distal ends. The ends have openings therein to allow optical fibers to pass therethrough. The openings in the distal end have a width that is less than twice the optical fiber's diameter. Dividers separate the distal end openings and have a projection that narrows the distal openings to prevent the optical fibers from accidentally moving out of the openings. A lid is also provided to assist with organization and compression of the optical fibers.

Abstract: The present invention relates to an accessory for high-voltage direct-current (HVDC) energy cables comprising: at least one element made from a crosslinked elastomeric polymer material, and at least one scavenging layer comprising zeolite particles. The zeolite particles are able to scavenge, very efficiently and irreversibly, the by-products deriving from the cross-linking reaction, so as to avoid space charge accumulation in the element during the accessory lifespan. Moreover, the zeolite particles can prevent the crosslinking by-products present in the element of a non-degassed accessory from migrating towards the insulating layer of the energy cable on which the accessory is mounted.

Abstract: Embodiments of the present invention provide a cable for optical fiber sensing applications formed from fiber wound around a cable core. A protective layer is then preferably placed over the top of the wound fiber, to protect the fiber, and to help keep it in place on the cable core. The cable core is preferably of a diameter to allow bend-insensitive fiber to be wound thereon with low bending losses. The effect of winding the fiber onto the cable core means that the longitudinal sensing resolution of the resulting cable is higher than simple straight fiber, when the cable is used with an optical fiber sensing system such as a DAS or DTS system. The achieved resolution for the resulting cable is a function of the fiber winding diameter and pitch, with a larger diameter and reduced winding pitch giving a higher longitudinal sensing resolution.

Abstract: According to embodiments of the present invention, an optical detection device is provided. The optical detection device includes an optics arrangement configured to generate an annular illumination pattern to illuminate a portion of a sample and further configured to receive a return light from the portion of the sample illuminated by the annular illumination pattern; and a detector arrangement configured to detect the return light. According to further embodiments of the present invention, an optical detection method is also provided.

Abstract: In one embodiment, a patch cord comprises: a communications cable that includes a first conductor and a second conductor that form a first differential pair, a third conductor and a fourth conductor that form a second differential pair; a fifth conductor and a sixth conductor that form a third differential pair, a seventh conductor and an eighth conductor that form a fourth differential pair; and a plug that is attached to a first end of the communications cable, the plug comprising: a plug housing that receives the communications cable; first through eighth plug contacts that each are at least partially within the housing and that are electrically connected to the respective first through eighth conductors; and a color identification tag that has a first color pattern that is a unique identifier for the patch cord.

Abstract: The present disclosure relates to a fiber optic network configuration having an optical network terminal located at a subscriber location. The fiber optic network configuration also includes a drop terminal located outside the subscriber location and a wireless transceiver located outside the subscriber location. The fiber optic network further includes a cabling arrangement including a first signal line that extends from the drop terminal to the optical network terminal, a second signal line that extends from the optical network terminal to the wireless transceiver, and a power line that extends from the optical network terminal to the wireless transceiver.

Abstract: A light-diffusing optical element with efficient coupling to light sources with high numerical aperture. The light-diffusing optical element includes a higher index core surrounded by a lower index cladding. The cladding includes scattering centers that scatter evanescent light entering the cladding from the core. The scattered light exits the element to provide broad-area illumination along the element. Scattering centers include dopants, nanoparticles and/or internal voids. The core may also include scattering centers. The core is glass and the cladding may be glass or a polymer. The element features high numerical aperture and high scattering efficiency.

Abstract: Devices, systems and methods to prevent damage to power and communication conductors located in cold occurring regions, with an elongated cylindrical tubular assembly of closed cell foam within an outer non-conductive durable outer coating, with a pull cord extending therethrough, wherein the assembly along with communication and power lines is pulled through new power and communication ducts and conduits and in retrofitting existing power and communication ducts, so that the assembly reduces the volume spacing in the ducts/conduits that can be damaged by water intrusion which expands during freeze conditions.

Abstract: A fiber optic cable includes a jacket forming a cavity therein, the jacket having an indentation on the exterior thereof that forms a ridge extending into the cavity along the length of the jacket; and a stack of fiber optic ribbons located in the cavity, each ribbon having a plurality of optical fibers arranged side-by-side with one another and coupled to one another in a common matrix, wherein corners of the ribbon stack pass by the ridge at intermittent locations along the length of the jacket, and wherein interaction between the ridge and the ribbon stack facilitates coupling of the ribbon stack to the jacket.

Abstract: A device for laser drilling, having: (a) a laser module (310), having a plurality of laser subsystems (200), each one of the laser subsystems (200) having an active optical fiber (240), wound in a shape of hollow coil and packaged inside a hollow cylindrical box (210), and at least one diode laser (220) mechanically connected perpendicularly to the hollow cylindrical box (210) and optically coupled to the core of the active optical fiber (240) wound and packaged inside the hollow cylindrical box (210), the laser module (310) having a tubular shape allowing cooling and drilling fluids to flow through the concentric hollow cores of the tubular laser module (310) and of the cylindrical box (210); and (b) an optical drill head (100), the optical drill head having an end (130) with orifices (110 and 120), and a body (140).

Abstract: According to one aspect, the invention relates to a device comprising an optical fiber having a high Brillouin threshold, said device including an optical fiber (101) suitable for propagating a high-power optical signal beam, means (11) for coupling a signal beam to an entrance end of the optical fiber (101) and a tubular structure (10) comprising at least one first tube (103) and at least one first adhesive material (102). According to the present description, at least one portion of the optical fiber is immobilized in the tubular structure (10) by means of the first adhesive material (102), which adheres both to the internal surface of the first tube (103) and to the external surface of the optical fiber (101).

Abstract: A rugged optical micromodule cable is provided. The cable includes a composite cable jacket including a first cable jacket layer formed from a first material and a second cable jacket layer formed from a second material. The first cable jacket layer provides at least 10% of the thickness of the cable jacket and the second cable jacket layer provides at least 10% of the thickness of the cable jacket. The first material is different than the second material, and each material provides different physical properties to the cable jacket.

Abstract: The present invention relates to a multi-core optical fiber that can realize suppression of crosstalk on an easy and inexpensive basis. The multi-core optical fiber is provided with a plurality of core portions extending along a central axis of the fiber, a common cladding portion integrally holding the core portions inside, a coating layer surrounding the common cladding portion, and a bend applying portion. The bend applying portion, as an example, is provided on a partial region of an outer periphery of the coating layer and applies bending stress to a glass region.

Abstract: An optical fiber cable for installation in a subterranean formation, where the temperature could be in excess of 150 degrees C. The optical fiber cable has an outer metallic jacket defining an elongated conduit with an internal elongated channel that receives an optical fiber. The optical fiber has two strands joined by a splice. A splice protector has a body with a passageway receiving the splice. The body has an outer region configured to be joined by a fusion weld to the outer metallic jacket.

Abstract: An optical fiber cable includes a jacket and modules including optical fibers. The jacket has an interior that forms an elongate conduit between proximal and distal ends. The modules extend lengthwise through the conduit without being bound together in a pattern of twisting or wound together in a pattern of stranding. Also, the jacket and modules are sized such that free space is provided within the conduit between the modules and the jacket. The jacket is at least ten meters long, and the orientation, alignment, and size of the modules allow individual modules to slide lengthwise relative to one another through the conduit. Pulling one of the modules from the proximal end of the jacket while holding the other modules fixed at the distal end of the jacket draws the one module further into the jacket on the distal end of the jacket.

Abstract: A cable that includes a first optical fiber in a center, a first layer with a plurality of metal wires and a stainless steel tube surrounding the first optical fiber, a second optical fiber inside the stainless steel tube, and a second layer with a plurality of metal wires surrounding the first layer, wherein the first optical fiber is directly exposed to the outside environment.

Abstract: An optical fiber cable assembly comprising an optical fiber slidably enclosed within a hollow tubing, both the fiber and the tubing having corresponding first and second ends. The cable is terminated with the first and second ends of the tubing and the fiber constrained with respect to each other such that fiber and the tubing are approximately the same length when the cable is at a first temperature. The tubing is made of a material which contracts more than the optical fiber when the cable is exposed to temperatures below the first temperature, such that the fiber is longer than the tubing and excess fiber length is formed.