Tyco Telecommunications (us) Inc.

Tyco Electronics Subsea Communications LLC

Subcom, LLC

Tycom (us) Inc.

Alexei N Pilipetskii

Morten Nissov

Dmitri G Foursa

Neal S Bergano

Georg Heinrich Mohs

Ekaterina A Golovchenko

Yi Cai

Maxim A Bolshtyansky

Hussam G Batshon

M Imran Hayee

Jin-Xing Cai

Oleg V Sinkin

Hongbin Zhang

Bo Pedersen

Jonathan A Nagel

Sergey Yurevich Ten

Carl R Davidson

Andrej B Puc

Yu Sun

Matthew V Mazurczyk

William Anderson

Alan J Lucero

Franklin Webb Kerfoot, Iii

Chinlon Lin

Dmitriy Kovsh

Hongsheng Wang

Jerzy R Domagala

R Brian Jander

Gregory M Wolter

Vincent J Mazurczyk

Michael A Mills

Matthew X Ma

William W Patterson

Chien-Jen Chen

Steven G Evangelides

Gerald E Lenner

Li Liu

Matthew Vincent Mazurczyk

Techniques for extending distributed acoustic sensing (DAS) range in undersea optical cables are provided. For example, DAS range can be extended by transmitting and amplifying a DAS signal along multiple spans of a first optical fiber, routing or bypassing the DAS signal from the first optical fiber to a second optical fiber different from the first fiber via a high-loss loopback architecture, and returning and amplifying the DAS signal along the same multiple spans back to a DAS device. The DAS device may then receive and process the DAS signal to detect any changes in the DAS environment. The loopback configuration may be based on different types of loopback architecture.

Extending DAS range in undersea cables using loopbacks

Disclosed are techniques and amplifier stages that include wave division multiplexers, semiconductor optical amplifiers and wave division demultiplexers that amplify optical signals. An input optical signal having a first bandwidth is partitioned into a plurality of subband optical signals by thin film filters tuned to a selected bandwidth that is less than the first bandwidth. Each of the plurality of subband optical signals has a bandwidth that is a portion of the first bandwidth. Each subband optical signal is input into a semiconductor optical amplifier that is tuned to the respective portion of the first bandwidth that corresponds to the subband optical signal. The combination of the partitioned input optical signal and tuned semiconductor optical amplifiers provides improved optical signal transmission performance by reducing polarization dependent gain.

Semiconductor based system and method for broad bandwidth transmission

Apparatus, systems, and techniques for extending distributed acoustic sensing (DAS) range in undersea optical cables over multiple spans, as well as providing span-specific DAS information, are provided.

Extending dynamic acoustic sensing range and localization in undersea cables using loopbacks

An apparatus for subsea environment sensing. In one aspect, the apparatus may include a repeater assembly, disposed in an optical repeater; and an environmental sensor assembly, disposed proximate to the repeater assembly, the environmental sensor assembly being coupled to receive power from the repeater assembly over an optical link.

Architecture, apparatus, and power delivery method for environmental measurement in subsea system

Techniques for improving gain equalization in C- and L-band ('C+L') erbium-doped fiber amplifier (EDFAs) are provided. For example, the C- and L-band amplification sections of a C+L EDFA may be separated and configured in a parallel arrangement or a serial arrangement. For both the parallel and serial arrangements, the C- and L-band amplification sections may share a common gain flattening filter (GFF) or each amplification section may include and employ a separate GFF. Moreover, in some examples, an “interstage” L-band GFF may be located before or upstream of the L-band amplification section such that the L-band optical signal is gain-equalized or flattened prior to the L-band amplification section amplifying the L-band.

Gain equalization in C+L erbium-doped fiber amplifiers

A line monitoring system may include a laser source to launch a plurality of pulsed probe signals; an optical transmission system, comprising a plurality of loopbacks, to receive the plurality of pulsed probe signals, and direct the plurality of pulsed probe signals through the plurality of loopbacks. The system may include a receiver to receive a plurality of return signals, derived from the plurality of pulsed probe signals from the transmission system, and a perturbance detection system, coupled to the receiver, to measure a phase difference between a polarization of a pair of return signals of the plurality of return signals. The pair of return signals may be received from a pair of loopbacks of the plurality of loopbacks, from a first loopback and a second return signal from a second loopback. The perturbance detection system may determine a location of a perturbation, based upon the phase difference.

Spatially resolved perturbation detection using line monitoring system

This spatial division multiplexing (SDM) in power-limited optical communication systems. In general, an SDM optical transmission system may be configured to increase data capacity over the data capacity of a non-SDM optical transmission system while maintaining power consumption at or below that of the existing non-SDM optical transmission system. To realize such an improvement in performance without increasing power consumption, an example SDM optical transmission may be constructed by reducing system bandwidth, reducing and/or altering equipment for filtering, reducing optical amplifier spacing, reducing operational amplifier power consumption, etc. In this manner, increased data transmission performance may be realized even where available power may be strictly limited.

Spatial division multiplexing in limited power optical communication systems

Optical amplifier assembly for spatial division multiplexing (SDM) optical communication systems. Each optical amplifier assembly includes a single pump assembly configured for causing amplification of signals traveling on separate fiber paths in different directions. Each fiber path includes a plurality of spatial dimensions. The single pump assembly includes a plurality of pump sources to provide redundancy and the optical amplifier assembly further includes splitters for splitting outputs of the pump sources to amplifiers coupled to the different spatial dimensions. Different modulation formats may be used on the different spatial dimensions with different pump power being provided to each of the modulation formats. Amplifiers with complementary outputs may be coupled to average out gain deviations.

Spatial division multiplexed optical communication systems and amplifiers for the same

A system and method for transmitting a wavelength division multiplexed (WDM) signal on an optical transmission path. The system includes at least one first modulation format transmitter configured to generate an associated first modulation format signal on an associated signal wavelength using a first modulation format having a first spectral efficiency, and at least one second modulation format transmitter configured to generate an associated second modulation format signal on an associated signal wavelength using a second modulation format having a second spectral efficiency higher than the first spectral efficiency. The second modulation format signals having an optical power set nominally higher than the optical power of the first modulation format signals. The first and second modulation format signals are combined into an aggregate output signal on the optical transmission path.

Transmission system and method using mixed modulation formats

An optical subcarrier multiplex system. An input data signal is jointly coded with at least one forward error correction (FEC) code before symbol mapping and before subcarrier modulation. Joint FEC coding mitigates non-uniform subcarrier performance.

Optical subcarrier multiplex system with joint forward error correction coding

A system and method including a transmitter including digital signal processor for providing a shaped data output in response to an input data stream. The shaped data output is coupled to a modulator that modulates an optical signal in response to the shaped data output to provide a non-rectangular shaped output having channel spacing greater than Nyquist channel spacing. Providing a shaped output consistent the present disclosure mitigates the effects of non-linear impairments in an optical transmission system.

System and method using spectral shaping and expanded channel spacing

A system and method involving a coded modulation scheme whereby different spectral efficiencies can be achieved for different transmitters in a WDM system using the same M-QAM modulation format. A maximum achievable spectral efficiency for the transmitters may be selected and a spectral efficiency step-size of the maximum achievable spectral efficiency may be specified. The spectral efficiency for any transmitter in the system may be individually selected by reducing its spectral efficiency from the maximum achievable spectral efficiencies by a selected number of steps corresponding to the step size.

Coded modulation for small step-size variable spectral efficiency

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Colts Neck, NJ, United States of America

Alexei N Pilipetskii