Ciena Corporation

David R Doucet

David W Boertjes

Jean-Luc Archambault

Yinqing Pei

Hamid Mehrvar

Salih Jasarevic

Bernard Thiboutot

Maurice M O'Sullivan

David Casson Bownass

Joanne Wakefield

Douglas W Charlton

A management system for an optical line system includes one or more processors and memory storing instructions that, when executed, cause the one or more processors to receive State of Polarization (SOP) measurements from one or more optical components in the optical line system, wherein the SOP measurements are taken while traffic-bearing channels are operating, and monitor health of one or more fibers based on the SOP measurements. The health can include detection and/or localization of SOP transients.

Integrated polarimeter in an optical line system

An optical line device for use in an optical line system is configured to connect to a second optical line device via a transmit fiber and a receive fiber. The optical line device includes a transmitter connected to the transmit fiber via an output port of the optical line device, wherein the transmitter is configured to transmit a polarization probe signal at a wavelength outside of a band of wavelengths used for traffic-bearing channels in the optical line signal, to a second polarimeter receiver at the second optical line device; and a polarimeter receiver connected to the receive fiber via an input port of the optical line device, wherein the polarimeter receiver is configured to receive a second polarization probe signal from a second transmitter transmitted from the second optical line device and to derive a measurement of SOP on the receive fiber based on the second polarization probe signal.

Short-term optical recovery systems and methods in coherent optical receivers minimize recovery time for fault scenarios and signal reacquisition while maintaining robust signal acquisition. The short-term optical recovery systems and methods include special techniques and algorithms to minimize recovery time, making coherent systems similar in time as conventional direct detection recovery. The short-term optical recovery systems and methods include an expedited acquisition engine that includes a reference clock recovery, a compensator to remove chromatic dispersion, a burst framer, and a compensator to remove polarization dispersion. Importantly, the expedited acquisition engine uses a memory oriented architecture to allow some properties of the acquisition engine to be stored during initial acquisition and, hence, later on be deployed in any fault scenario to expedite further recovery of a signal.

Short-term optical recovery systems and methods for coherent optical receivers

A polarimeter includes a Polarization Maintaining (PM) coupler with an input configured to receive input light and split the input light to a first output and a second output; a first PM fiber coupled to the first output; a second PM fiber coupled to the second output; a first polarization device coupled to the first PM fiber; a second polarization device coupled to the second PM fiber; and a plurality of detectors coupled to the first polarization device and the second polarization device, wherein outputs i, i, i, iare determined based on outputs of the plurality of detectors, the outputs i, i, i, iare linear projections of corresponding Stokes Parameters of the input light.

A polarimeter system integrated into an optical line system includes a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light from the filter and to measure various outputs of the varied arrangement to derive measurement of State of Polarization (SOP) of the input light.

New optical ground wire (OPGW) cable structures are proposed. These OPGW cables are designed to reduce or minimize the net magnetic field Bparallel to the direction {circumflex over (z)} of light propagation resulting from a lightning strike on the cable. A reduction in the net magnetic field Bparallel to the direction {circumflex over (z)} of light propagation yields a reduction in the amount and speed of state of polarization (SOP) rotation resulting from a lightning strike on the cable due to the Faraday effect. OPGW cables constructed according to these new OPGW cable structures fulfill their dual function to shield the high-voltage conductors from lightning strikes and to support coherent optical communications.

Reduction of Faraday effect in optical ground wire (OPGW) cables

Systems and methods using a polarimetric measurement device to localize a source of one or more State of Polarization (SOP) transients affecting one or more optical fibers are disclosed. The method includes transmitting a signal into a fiber in a first direction; receiving, at the polarimetric measurement device, the signal from one of the fiber and another fiber collocated in a bundle with the fiber in a second direction; and processing data from the polarimetric measurement device to determine a location of the one or more SOP transients. The processing can include detecting a presence of the one or more SOP transients based on a first signature and its echo seen in the data; and converting a time between the echoes into a distance.

Systems and methods using a polarimeter to localize state of polarization transients on optical fibers

The present disclosure provides short-term optical recovery systems and methods in coherent optical receivers to minimize recovery time for fault scenarios and signal reacquisition while maintaining robust signal acquisition. The short-term optical recovery systems and methods include special techniques and algorithms to minimize recovery time. The short-term optical recovery systems and methods include an expedited acquisition engine that includes a reference clock recovery, a compensator to remove chromatic dispersion, a burst framer, and a compensator to remove polarization dispersion. Importantly, the expedited acquisition engine uses a memory-oriented architecture to allow some properties of the acquisition engine to be stored during initial acquisition and, hence, later on be deployed in any fault scenario to further expedite recovery of a signal. The expedited acquisition engine leverages on a frequency aligned Local Oscillator (LO) as well as pre-calculated dispersion maps and equalizer coefficients.

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Almonte, Canada

David R Doucet