Lucent Technologies Inc.

At&t Bell Laboratories

At+t Corp.

American Telephone & Telegraph Co., At&t Bell Laboratories

Fitel USA Corporation

Nathan E Hardwick, Iii

Peter A Weimann

Carl Raymond Taylor

Kenneth Wade Jackson

Jim Jenqtsong Sheu

Clyde Jefferson Lever, Jr

Richard Dalton Small, Jr

Richard Hartford Norris

John James Blee

Candido J Arroyo

Parbhubhai D Patel

Phillip Maurice Thomas

Michael D Kinard

Richard Norris

Paul F Gagen

Krishnaswamy Kathiresan

David M Mitchell

Scott Thomas Davies

Wing S Liu

Walter J Paucke

Lawrence R Dunn

Dan L Philen

Peter A Woog

Robert P Mohalley

LaVerne C Hotchkiss

A buffer encasement has a longitudinally extending interior surface that extends around and defines a longitudinally extending passage containing a stack of optical fiber ribbons. The interior surface closely bounds the stack, and the buffer encasement is easily removable from the stack. The buffer encasement can be is easily removable from the stack because the buffer encasement is thin and is constructed of a material that is capable of being easily torn. The buffer encasement can be is easily removable from the stack because the buffer encasement defines a longitudinally extending weakened portion that is capable of being more easily torn than the remainder of the buffer encasement. The weakened portion is operative so that when the weakened portion is torn the buffer encasement defines longitudinally extending edges on the opposite sides of the tear. The edges can be separated from one another to define an opening therebetween through which the stack of optical fiber ribbons can be accessed. The buffer encasement can be in the form of a longitudinally extending piece of tape having longitudinally extending opposite edges defining an overlapping configuration so that the tape encloses the stack of optical fiber ribbons. The edges of the tape can be separated to provide a nonoverlapping configuration in which an opening is defined between the edges and through which the stack of optical fiber ribbons can be accessed. Therefore, the edges of the tape can be reclosed, if desired.

Groups of optical fibers closely bound by easily removable buffer encasements, and associated fiber optic cables

An optical module includes a stack of optical fiber ribbons that are within a buffer encasement, such as a thin sheath, that closely bounds the periphery of the stack. The optical modules can be rectangular, so that the optical modules can be readily stacked in a manner that results in a very space efficient fiber optic cable. The optical modules can be tested prior to being incorporated into the fiber optic cable so as to maximize the probability of the fiber optic cable being fully operable. The sheath cushions all of the sides of the stack. In some optical modules, the stack is movable relative to the sheath and the optical fiber ribbons are movable relative to one another. The sheath is preferably sufficiently rigid to maintain the stack in a stacked configuration, and sufficiently flexible to allow the optical fiber ribbons to slide laterally relative to one another so that, in an end elevation view of the stack, the stack and the sheath can transition from a non-skewed configuration to a skewed configuration. The lateral displacement between the optical fiber ribbons in the skewed configuration is different from the lateral displacement between the optical fiber ribbons in the non-skewed configuration. The stack can be in a longitudinally twisted configuration, and the sheath is sufficiently rigid to hold the stack in the longitudinally twisted configuration. Further, the sheath can be thin such that the exterior surface of the sheath defines ridges that correspond to the twist of the stack.

Stacks of optical fiber ribbons closely bound by respective buffer encasements, associated methods, and associated fiber optic cables

A fiber optic cable includes multiple differently sized stacks of optical fiber ribbons. The stacks include a central stack that is approximately centrally located in a jacket passage and peripheral stacks positioned radially around the central stack. A difference exists between the dimensions of the central stack and the dimensions of one or more of the peripheral stacks. Another fiber optic cable has multiple longitudinally extending stacks of optical fiber ribbons that are within a jacket passage. The stacks include a central stack that is approximately centrally located in the jacket passage, and peripheral stacks positioned radially around the central stack. Buffer encasements that respectively contain the peripheral stacks are longitudinally stranded around the central stack. Each buffer encasement includes a longitudinally extending interior surface that extends around and defines a longitudinally extending passage that contains the respective peripheral stack, and each interior surface closely bounds and engages a substantial portion of the periphery of the respective peripheral stack. Another fiber optic cable includes multiple optical modules within a longitudinally extending jacket and longitudinally stranded around a central member. Each optical module includes a stack of optical fiber ribbons enclosed in a buffer encasement. Each buffer encasement includes a longitudinally extending interior surface that extends around and defines a longitudinally extending passage that contains the respective stack, and the interior surface closely bounds and engages a substantial portion of the periphery of the respective stack.

Fiber optic cables with multiple stacks of optical fiber ribbons

A stack of optical fiber ribbons is enclosed in a buffer encasement having a relatively soft inner portion and an relatively hard outer portion. The inner portion has an interior surface extends around and defines a longitudinally extending passage that contains the stack, and the interior surface closely bounds the stack. The outer portion extends around, closely bounds and contacts the inner portion, and has a modulus of elasticity that is greater than the modulus of elasticity of the inner portion. In accordance with one example of the invention, the inner portion has an exterior surface that extends around and is spaced apart from the passage, and the outer portion has an interior surface that extends around, closely bounds, and engages the exterior surface of the inner portion, whereby the buffer encasement has multiple plies. In contrast, in accordance with another example of the invention, a surface is not defined between the inner portion and the outer portion.

Stacks of optical fiber ribbons closely bound by respective buffer encasements with relatively hard exteriors and relatively soft interiors, associated methods, and associated fiber optic cables

An underwater optical fiber cable is constructed from a terrestrial optical fiber cable by hermetically enclosing the terrestrial optical fiber cable with a hydrogen barrier such as a copper tube or by using a terrestrial optical fiber cable having a hydrogen barrier therein, and by wrapping at least one layer of galvanized armor wires outside of the hydrogen barrier. As so reinforced, the terrestrial optical fiber cable has the strength needed for an underwater optical fiber cable by using relatively inexpensive galvanized armor wires. Although the galvanized armor wires generate hydrogen by contact with water, this hydrogen is prevented from adversely affecting optical fibers in the terrestrial optical fiber cable by the presence of the hydrogen barrier. Advantageously, a standard terrestrial optical fiber cable can be chosen from the many types available including high fiber count designs. Therefore, the flexibility of the core terrestrial cable choices permits system optimization and compatibility of underwater cores with shore cables without a proliferation of limited underwater cable designs. Also, the terrestrial optical fiber cable can be selected to include no hydrogen-generating material inside of the hydrogen barrier. Thus, the optical fiber cable of this invention will inherently have greater long-term reliability and, in the event of a rupture or leak in the hydrogen barrier, will last longer than optical fiber cables using hydrogen-generating material inside of a hydrogen barrier.

Optical fiber cable for underwater use using terrestrial optical fiber

A hybrid cable (20) includes a first transmission portion such as a metallic conductor portion (22) and a second transmission portion such as an optical fiber portion (24). The metallic conductor portion includes a core which includes twisted pairs of metallic conductors enclosed in a plastic core wrap, a shielding system and a plastic jacket (48). A longitudinally extending duct (52) is disposed in engagement with an outer surface of the plastic jacket of the metallic conductor portion. An outer plastic jacket (60) is disposed about the duct and the metallic conductor portion. An optical fiber cable (50) or optical fibers (51, 51) may be caused to become disposed initially in the duct or when the use of fibers becomes economically justified.

Hybrid communications cable for enhancement of transmission capability

A communications cable for use in buried environments in an outside plant includes a core (22) comprising at least one transmission medium and a mechanically strengthened, thermal resistant barrier layer (40) disposed about a plastic tubular member (23). A metallic shield (32) and a plastic jacket (36) are disposed about the barrier. The barrier layer may comprise a tape (41) which is made of a material such as woven glass or an aramid fibrous material, for example, which is resistant to relatively high temperatures, which has suitable strength properties in all directions and at elevated temperatures and which is characterized by properties which cause the barrier layer to impede the passage therethrough of particles which are sufficiently large to cause damage to the core. In a preferred embodiment, the thermal barrier layer also includes provisions for preventing the longitudinal flow of water within the cable. Such a waterblocking capability may be provided by a barrier layer comprising a laminate comprising a high temperature resistant tape and at least one other tape with a superabsorbent powder therebetween or another tape which has been impregnated with a superabsorbent material.

Cable having lightning protective sheath system

An underwater optical fiber cable (20) which is substantially free of hydrogen generation includes a core portion (22) which includes an optical transmission medium and which may comprise a terrestrial cable and a sheath system which may be an oversheath for the terrestrial cable. An outer portion of the sheath system includes a plurality of longitudinally extending strength members (42--42) each being made of a metal having a relatively low chemical or electrochemical reactivity. Covering individually each strength member is a plastic material (60) such as polyethylene.

Underwater optical fiber cable

An optical fiber connector of the continuous groove type comprising a substrate with a multiplicity of fiber-receiving grooves thereon, and a cover member comprising compliant fiber-contacting material having a modulus of elasticity less than about 10.sup.6 psi (less than about 6.9 GPa), preferably less than 10.sup.5 psi. Connectors according to the invention can have low loss, and low added loss during thermal cycling. In a particular preferred embodiment, the substrate is a molded plastic part, and the compliant material is an adhesive-backed polyester film.

Optical fiber connector and articles connected therewith

Growing community of inventors

Dunwoody, GA, United States of America

Nathan E Hardwick, Iii