Huawei Technologies Co., Limited

Future Wei Technologies, Inc.

Rensselaer Polytechnic Institute

Huawei Technologies Canada Co., Ltd.

Universitè Laval

Zhiping Jiang

Zhuhong Zhang

Xuefeng Tang

Chuandong Li

Jian Zhong

Xi-Cheng Zhang

Jianhong Ke

Choloong Hahn

Junho Chang

Dajiang Jin

Minggang Si

Ali Ahmed Ali Massoud

Chen Chen

Yan Cui

Xiaodong Luo

Ali Salehiomran

Haitao Sun

Jiachuan Lin

Yuren You

Yasser Chiniforooshan

Qin Chen

Xiang Lin

Lixian Wang

Jun Luo

Eric Bernier

Hamid Mehrvar

Ming Li

Mohammad Mehdi Mansouri Rad

Hong Yang

Rui Bang He

Demin Yao

Yansui Huang

Sophie La Rochelle

Suet Yuen

Frédéric Maes

Yang Ren

Charles Matte-breton

Mahdi Hemmati

Hongbiao Gao

Masahiko Tani

Xie George Xu

Vien Van

Simin Wang

Abbas Javadtalab

Behnam Naghdi

Qingyi Guo

Tejia Liu

Jiang Tang

A method for monitoring impairment includes: receiving a first received waveform sent by the coherent receiver; obtaining a second received waveform including a first sub-waveform and a second sub-waveform with a relative first delay therebetween according to the first received waveform; obtaining a template at a predetermined location on the fiber link according to the second received waveform, wherein the template is used for representing a nonlinear noise by a first sub-signal waveform and a second sub-signal waveform at the predetermined location that are respectively obtained from the first sub-waveform and the second sub-waveform and have the first delay therebetween; obtaining a correlation between the second received waveform and the template; changing a value of the first delay to obtain values of the correlation corresponding to different values of the first delay; and outputting a value of the first delay corresponding to a maximum value of the correlation as impairment estimation.

Method and device for monitoring impairment, coherent receiver and network apparatus

A method for monitoring generalized optical signal-to-noise ratio (gOSNR) is provided, which is applied to monitoring of an optical signal received by a coherent receiver through a fiber link. The method includes: obtaining a first received waveform; obtaining a signal part of the first received waveform; obtaining a noise part of the first received waveform according to the signal part and the first received waveform; obtaining a first correlation between the noise part and a first template at a predetermined location on the fiber link, the first correlation indicating a signal power at the predetermined location; obtaining a second correlation between the noise part and a second template at the predetermined location on the fiber link, the second correlation indicating a signal power and noise power at the predetermined location; and obtaining gOSNR at the predetermined location according to the first correlation and the second correlation.

Method and device for monitoring generalized optical signal-to-noise ratio, coherent receiver and network apparatus

The disclosed systems and methods are for reducing polarization dependent loss in an optical link including: i) changing, by a state of polarization (SOP) controller, an SOP of an optical signal propagating in the optical link; ii) computing, by a link controller, a polarization dependent loss (PDL) in a portion of the optical link; iii) generating, by the link controller, a control signal according to the PDL; and iv) based on the control signal, changing, by the SOP controller, the SOP of the optical signal.

System and method for reducing polarization dependent loss in an optical link

A method for measuring polarization-dependent loss (PDL) of an optical link segment. The method has the steps of: measuring powers of first and second pilot tones (PTs) in a polarization-multiplexed (PM) optical signal at first and second link locations at or about an input and an output end of the optical link segment, respectively, the PM optical signal having first and second optical signals with orthogonal polarizations and amplitude-modulated by the first and second PTs, respectively; calculating a first orthogonal polarization power ratio (OPPR) of the first and second PTs using the powers thereof measured at the first link location; calculating a second OPPR of the first and second PTs using the powers thereof measured at the second link location; and calculating the PDL of the optical link segment based on a comparison between the first and second OPPRs.

System, apparatus, and method for online distributed polarization-dependent loss monitoring

Apparatuses and methods are described for generating an optical signal in an optical network. The apparatus comprises at least a first and a second laser configured to generate a first or second series of optical pulses respectively and a polarization beam combiner (PBC). The PBC is configured to receive the first and second series of optical pulses. Each optical pulse in the first series of optical pulses is received with a first state of polarization (SOP), and each optical pulse in the second series of optical pulses is received with a second SOP. The first SOP and second SOP is orthogonal with respect to each other, and the PBC is further configured to combine the first and second series of optical pulses and to output an un-polarized optical signal. The un-polarized optical signal may help to reduce or mitigate nonlinear optical impairments caused by polarization of the optical signal.

Apparatuses and methods for generating an optical signal in an optical communication network

The disclosed systems and methods for determining spectrum-resolved signal-to-noise ratio (SNR) in an online dense wavelength division multiplexing (DWDM) optical link, the method comprising: i) receiving a noise affected optical signal; ii) converting the received optical signal into a digital signal; iii) processing the digital signal to extract the noise affected transmitted signal; iv) decoding the noise-affected transmitted signal and reconstructing an original transmitted signal; v) converting the noise-affected transmitted signal into frequency domain noise-affected transmitted signal; vi) converting the original transmitted signal into frequency domain original transmitted signal; vii) selecting spectrum slices from the frequency domain noise-affected transmitted signal and the frequency domain original transmitted signal; viii) converting the spectrum slices into time domain portions of the noise-affected transmitted signal and the original transmitted signal respectively; ix) correlating the time domain portions of the noise-affected transmitted signal and the original transmitted signal; and x) determining the spectrum-resolved SNR.

Systems and methods for determining spectrum resolved SNR in an online dense wavelength division multiplexing optical link

System and method for managing spectral hole burning (SHB) effect in an optical transport network (OTN) link. The method is performed by an automatic gain control (AGC) circuit of an amplification assembly of the OTN link. The method comprises determining, via a first photodetector communicatively connected to the AGC circuit, an input power of an income signal and, in response to the input power being less than a predetermined portion of a full-loading signal power, causing a pump power variable attenuator (PVOA) of the amplification assembly to attenuate pump power from a pump source, the PVOA being disposed optically intermediate a first doped fiber and a second doped fiber of the amplification assembly.

Assemblies and methods for managing spectral hole burning

Aspects of the disclosure provide a method of a LiDAR system to determine the distance of an object from the LiDAR system. Embodiments of the LiDAR system can use a coarse estimate of the distance of an object from the LiDAR system which is then used by a fast search to determine an estimate of the distance of an object from the LiDAR system within a precision threshold. In some embodiments the LiDAR system can use adaptive precision when determining the distance of an object from the LiDAR system.

Method and apparatus for a computationally efficent LiDAR system

The disclosed systems and methods are for monitoring optical performance in a spatial division multiplexing (SDM) system, comprising: i) extracting, by an optical coupler, at least a portion of a plurality optical signals propagating in different communication lanes of the SDM-based optical communication system, wherein each optical signal of the plurality of optical signals is modulated with a distinguishable pilot tone (PT) signal; ii) combining, by the optical coupler, the extracted portion of the plurality of optical signals, and generate a combined optical signal; iii) extracting, by a pilot tone detector (PTD), PT signals from the combined optical signal; iv) determining, by the PTD, optical signal specific information included in the PT signals; and v) computing, by the PTD, optical power of each optical signal based on the optical signal specific information.

System and method for monitoring optical performance in a spatial division multiplexing system

The disclosed systems, and methods for detecting an improper protection in an optical communication network comprising: i) receiving, by a first Coherent-Optical Time Domain Reflectometer (C-OTDR), a first reflected optical signal from a first optical fiber; ii) receiving, by a second C-OTDR, a second reflected optical signal from a second optical fiber; iii) pre-processing, by a processor, the first reflected optical signal and the second reflected optical signal; iv) determining, by the processor, a category of the first C-OTDR and the second C-OTDR; v) depending upon the category of the first C-OTDR and the second C-OTDR, computing a correlation between the first preprocessed reflected optical signal and the second preprocessed reflected optical signal based on a first correlation computation technique or a second correlation computation technique; and vi) based on the computed correlation, detecting the improper protection in the optical communication network.

Method and system for detecting an improper protection in an optical communication network

An optical fiber configured to improve the pump conversion efficiency of an L-band fiber amplifier which uses the multimode pump source. By directly absorbing multimode light including 915 nm, an active fiber core region co-doped with both erbium and ytterbium can provide gain to the L-band signals via stimulated emission. The unwanted C-band amplified spontaneous emission (ASE) light generate from this active fiber core region can be absorbed by another active fiber core region doped with erbium, then provides additional gain to the L-band signals. Active regions and cladding can be configured to match a given spatial mode of the optical signal. Signal-pump combiners with end-coupling or side coupling can be used.

Systems and methods to increase pump conversion efficiency of an optical fiber

System and method for improving performance in an optical link. The optical link includes a plurality of communication channels for transmitting an optical signal. The method is performed by a link controller of the optical link. The method comprises determining a noise level of at least one channel of the plurality of channels, determining a launch power offset for the at least one channel and performing link commissioning based at least in part on the launch power offset.

Method and system for improving performance in an optical link

The disclosed systems and methods for detecting a location of reflection in an optical link comprising: i) receiving an optical signal; ii) receiving a plurality of first type of delayed optical signals corresponding to the optical signal; iii) determining a first type of time delays associated with each of the plurality of first type of delayed optical signals; iv) receiving a plurality of second type of delayed optical signals corresponding to the optical signal; v) determining a second type of time delays associated with the each of the plurality of second type of delayed optical signals; vi) computing relative delays from the second type of time delays; vii) comparing the relative delays with the first type of time delays; and viii) determining a location of a given optical element contributing to the reflections based on the given relative delay and the location of the AR.

Systems and methods for detecting a location of the optical elements causing multipath interference in an optical link

The disclosed systems, structures, and methods are directed to risk assessment of an optical network. A simulation framework includes a risk map engine including a performance prediction engine that generates a simulation of the optical network based at least in part on an input network topology and/or service map. The prediction performance engine runs the simulation to predict, based at least in part on received network telemetry data, direct and indirect impacts on the optical network of a risk factor represented in a what-if scenario. The risk map engine includes a risk assessment engine that determines a risk associated with the risk factor based at least in part on the predicted direct and indirect impacts and on a likelihood of occurrence of the risk factor. The risk assessment engine generates a risk map showing aggregate risks to the optical network from a plurality of risk factors.

Risk map for communication networks

Aspects of the disclosure provide for methods and systems for feedback control of mode MUX and DEMUX. An aspect of the disclosure provides for a method associated with a mode MUX. The method includes modulating each WDM signal of a first set of WDM signals with a pilot tone of different frequency. The method further includes spatially multiplexing the first set of WDM signals to generate a multi-mode signal. The method further includes detecting the pilot tones from the multi-mode signal. The method further includes tuning the mode MUX based on the detecting. Another aspect of the disclosure provides for a method associated with a mode DEMUX. The method includes spatially demultiplexing a multi-mode signal into a set of WDM signals. The method further incudes detecting pilot tones from the set of WDM signals and tuning the mode DEMUX based on the detecting.

Methods and apparatus for feedback control of mode MUX and DEMUX

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Kanata, Canada

Zhiping Jiang