Tyco Telecommunications (us) Inc.

Tycom (us) Inc.

Corvis Corporation

Dorsal Networks, Inc.

Other

Sowilo Networks, Inc.

Bo Pedersen

M Imran Hayee

Nandakumar Ramanujam

Cathal Mahon

Ronald E Johnson

Alexei N Pilipetskii

Chinlon Lin

Neal S Bergano

Morten Nissov

Franklin Webb Kerfoot, Iii

Ronald D Esman

Lee Daniel Feinberg

William Shieh

John G Hagopian

Brent Ashley Miller

Anhui Liang

Dalma Novak

Quan Wang

Ekaterina A Golovchenko

Howard D Kidorf

Michael L Dennis

Stuart M Abbott

George T Harvey

Stephen G Evangelides, Jr

Quan-Zhen Wang

Michael A Mills

Austin Farnham

Dimitri Foursa

Chien-Jen Chen

Michael S Petersen

Nadakumar Ramanujam

Gerald E Lenner

An optical signal receiver including a plurality of threshold decision circuits configured to receive an electrical signal representative of the optical signal. Each of the threshold decision circuits is configured to sample the electrical signal and to provide an associated threshold decision circuit output in response to a comparison of the signal to an associated threshold level. The threshold decision circuit outputs are coupled to an output decision circuit, which is configured to output a signal representative of a binary state of the optical signal. An optical communication system and a method of reconstructing received data signal in an optical communication system are also provided.

Multiple detector decision receiver

An optical transmission system includes a number of corresponding modular multiplexing and demultiplexing units used in transmitting and receiving an optical signal respectively. Additionally, compensation components compensate for optical dispersion experienced by the optical signal. The modular multiplexing and demultiplexing units are assembled in a cascade fashion at the transmit side and the receive side of the optical transmission system, respectively. The dispersion compensation components share dispersion compensation fiber across the cascaded units.

Modular multiplexing/demultiplexing units in optical transmission systems

High power repeaters for use in amplifying optical data signals transmitted through undersea fiber optic cables are disclosed. Raman amplification schemes using 100 or more pump lasers are integrated into industry standard sized pressure vessels for amplifying optical data signals transmitted through one or more fiber optic pairs. Other repeater features include high density packaging, efficient power distribution, and component sharing.

High power repeaters for Raman amplified, wave division multiplexed optical communication systems

A hybrid Raman-EDFA provides gain equalization over the C-band and L-band. The hybrid Raman-EDFA includes a Raman section producing a Raman gain and an EDFA section producing an EDFA gain complementing the Raman gain. The EDFA section preferably includes a highly inverted, single-stage EDFA to produce the complementing EDFA gain shape. One embodiment of the EDFA section includes a high return loss termination located after the erbium fiber to receive unabsorbed pump power. Multiple hybrid Raman-EDFAs can be connected in an amplifier chain in a transmission system. The transmission system preferably provides a dispersion map including regular composite fiber spans followed by at least one compensating span of negative dispersion fibers. The Raman sections of the hybrid Raman-EDFAs are preferably coupled to negative dispersion fiber in the transmission system.

Hybrid Raman/erbium-doped fiber amplifier and transmission system with dispersion map

A method and apparatus for performing error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a transmission system. The encoded data is decoded using the codes and three levels of decoding.

Concatenated forward error correction decoder

A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1&#xd7;2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur. The fiber optic system may also be utilized for a land-based system, having high probability of fiber cut regions and low probability of fiber cut regions.

Split redundant trunk architecture using passive splitters and path switching

A system and method of providing a transmission span for a telecommunications link based on a remote Er-doped fiber amplification scheme is provided, where a transmission span comprises first through third segments each respectively comprising first-third optical fibers having first-third fiber lengths and first-third physical properties. The first and third segments are optically coupled to opposing ends of the second segment. At least one of the first and third physical properties is different from the second physical property, where the first segment provides low nonlinearity, the third segment provides distributed gain, and the second segment compensates for the dispersion of the first and third segments. The span also includes a fourth optical fiber that is doped with a non-zero concentration of Er, and is disposed at a location in the span for remote pumping to provide discrete amplification of the optical signal. The location can be within the first segment, within the second segment, within the third segment, at an interface between the first and second segments, and/or at an interface between the second and the third segments.

Method and system for dispersion maps and enhanced distributed gain effect in long haul telecommunications using distributed and remotely pumped erbium-based amplification

An optical communications system, including first terminal equipment, second terminal equipment, third terminal equipment, a first powered optical segment connected to the first terminal equipment and including at least one amplifier, a second powered optical segment connected to the second terminal equipment and including at least one amplifier, an unpowered optical segment connected to the third terminal equipment, and a branch unit connecting the first powered segment, the second powered segment, and the unpowered segment via passive, all-optical connections, and wherein the unpowered segment is pumped with optical energy through the branch unit from at least one of the amplifiers in the first and second powered segments.

Optical communications systems including a branching unit and associated devices and methods

A method of increasing capacity on a long-haul undersea cable system having at least one optical fiber, said method comprising interleaving counter-propagating forward-propagating and backward-propagating signals in forward and backward channels on a common optical fiber, wherein the wavelength offset between said forward and backward channels is typically half of the channel spacing of co-propagating signals.

System and method for increasing capacity of long-haul optical transmission systems

A system and method of providing a transmission span that compensates for signal attenuation, dispersion, and nonlinearity of an optical signal communicated between two line units of a transmission link includes dividing the transmission span into a plurality of fiber segments and selecting a particular fiber for each of the segments. The fiber selection and arrangement of fibers within the span can be selected in accordance with the nonlinearity, dispersion conditions, and distributed gain conditions of the constituent fibers. In a three segment map, the first segment can provide low non linearity, the third segment can provide distributed gain, and the second segment can compensate for the dispersion of the first and third segments. The span can be used, e.g., for distributed Raman amplification. The span can alternatively include a two segment map, a four segment map, or a map with additional segments.

Method and system for dispersion maps and enhanced distributed gain effect in long haul telecommunications

A method and apparatus to perform error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a long-haul transmission system. The encoded data is decoded using the codes and three levels of decoding.

An apparatus comprises operationally coupled optical fiber segments that define an optical sublink. The optical sublink has link spans including a first link span and a second link span. The first link span has an average dispersion with a magnitude greater than zero. The second link span has an average dispersion with a magnitude greater than zero. The optical sublink has an end-to-end dispersion less than an end-to-end dispersion tolerance limit.

Method and apparatus for the optimization of dispersion map using slope-compensating optical fibers

A WDM optical communication system is provided that includes a transmitter and a receiver. An optical fiber transmission path couples the transmitter to the receiver. The transmission path includes at least one repeater having an optical amplifier located therein. A dispersion compensator is disposed at an intermediate point along the transmission path. The intermediate point is located outside of the repeater. The compensator includes a wavelength routing device for dividing a signal having a prescribed bandwidth into a plurality of distinct sub-bands. A plurality of output paths is provided for respectively receiving the plurality of distinct sub-bands. The dispersion compensator also includes a dispersion compensating optical element coupled to each of the output paths. Each dispersion compensating optical element substantially compensates for dispersion at a prescribed wavelength within the bandpass of its respective sub-band. A coupler recombining the distinct sub-bands and couples them back onto the optical fiber transmission path.

Method and apparatus for providing chromatic dispersion compensation in a wavelength division multiplexed optical transmission system

A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1&times;2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur. The fiber optic system may also be utilized for a land-based system, having high probability of fiber cut regions and low probability of fiber cut regions.

Growing community of inventors

Annapolis, MD, United States of America

Bo Pedersen