Abstract: An optical node includes one or more Optical Add/Drop Multiplexer (OADM) devices which each form a respective degree connected to an associated Optical Multiplex Section (OMS) section of a cascaded optical network including a plurality of OMS sections; and a channel holder source connected to the OADM devices, wherein the OADM device is configured to detect a local fault affecting one or more traffic signals and switch to the channel holder source to provide a respective channel holder the one or more traffic signals with a same power level and spectral location such that the respective channel holder replaces a respective traffic signal at the OADM device which is a first switching port after the fault and such that all other OADM devices at other optical nodes downstream from the fault remain switched to the one or more traffic signals due to a presence of the provided respective channel holder.

Abstract: 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.

Abstract: A system includes a processor communicatively coupled to an Amplifier Stimulated Emission (ASE) source and an optical receiver, wherein the processor is configured to cause transmission of one or more shaped ASE signals, from the ASE source, on an optical fiber, obtain received spectrum of the one or more shaped ASE signals from the optical receiver connected to the optical fiber, and characterize the optical fiber based in part on a nonlinear skirt and/or center dip depth in the received spectrum of the one or more shaped ASE signals. The one or more shaped ASE signals can be formed by the ASE source communicatively coupled to a Wavelength Selective Switch (WSS) that is configured to shape ASE from the ASE source to form the one or more shaped ASE signals with one or two or multiple peaks and with associated frequency.

Abstract: 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 i1, i2, i3, i4 are determined based on outputs of the plurality of detectors, the outputs i1, i2, i3, i4 are linear projections of corresponding Stokes Parameters of the input light.

Abstract: A method, a controller, and an optical network element are configured to perform steps of monitoring one or more optical links each formed by optical transceivers which are configured to provide variable capacity via a plurality of modulation formats; based on the monitoring, causing corresponding optical transceivers for the one or more optical links to operate at a first modulation format different from a second modulation format providing excess capacity; and mapping the excess capacity to bandwidth useable by one or more services managed by the one or more of the management system, the management plane, and the control plane.

Abstract: A computer-implemented method is implemented in one of a Network Management System (NMS), an Element Management System (EMS), a Software Defined Networking (SDN) controller, and a server executing an SDN application, to increase capacity of one or more links in an optical network. The computer-implemented method includes determining Net System Margin comprising a metric of overall excess margin in the optical network until a Forward Error Correction (FEC) limit is reached; performing an optimization of a plurality of parameters of the optical network to determine which settings are appropriate in the optical network to provide the increased capacity and to consume at least part of the Net System Margin; and causing a plurality of modems in the optical network to change settings based on the optimization to provide the increased capacity.

Abstract: Systems and methods of optical restoration include, in an optical network with a photonic service operating between two nodes via an associated optical modem at each node, wherein each modem is capable of supporting variable capacity, C1, C2, . . . , CN where C1>C2> . . . >CN, detecting a fault on a home route of the photonic service while the photonic service operates at a home route capacity CH, CH is one of C1, C2, . . . , CN?1; downshifting the photonic service to a restoration route capacity CR, CR is one of C2, C2 . . . , CN and CR<CH; switching the photonic service from the home route to a restoration route while the photonic service operates at a restoration route capacity CR; and monitoring the photonic service during operation on the restoration route at the restoration route capacity CR for an upshift.

Abstract: An optical node includes one or more Optical Add/Drop Multiplexer (OADM) devices which each form a respective degree connected to an associated Optical Multiplex Section (OMS) section of a cascaded optical network including a plurality of OMS sections; and a channel holder source connected to the OADM devices, wherein the OADM device is configured to detect a local fault affecting one or more traffic signals and switch to the channel holder source to provide a respective channel holder the one or more traffic signals with a same power level and spectral location such that the respective channel holder replaces a respective traffic signal at the OADM device which is a first switching port after the fault and such that all other OADM devices at other optical nodes downstream from the fault remain switched to the one or more traffic signals due to a presence of the provided respective channel holder.

Abstract: Systems and methods include managing optical spectrum in an optical network utilizing a flexible grid where each channel in the optical network has a center frequency and utilizes a plurality of bins to define spectral width, wherein each channel's occupancy on the optical spectrum is enumerated by its center frequent and plurality of bins.

Abstract: Systems and methods include, in a controller, responsive to a request to add one or more channels to a path in an optical network which has in-service channels, determining a plurality of logical control seams to split the path, wherein the path includes a plurality of optical sections and each logical control seam has a boundary at an associated optical section; determining controller speed for each of the plurality of logical control seams based on corresponding optical margin; and performing, for each of the plurality of logical control seams, control at the determined controller speed to add the one or more channels with the in-service channels.

Abstract: A controller includes a processor; and memory storing instructions that, when executed, cause the processor to obtain measurements of optical spectrum from an Optical Power Monitor (OPM) connected to a fiber having thereon, one or more optical signals from one or more optical transmitters, wherein the optical signals are based on a flexible grid, manage the one or more optical signals utilizing a first model and manage attenuation control granularity of a Wavelength Selective Switch (W SS) connected to the fiber utilizing a second model, and configure one or more of the W SS and the one or more optical transmitters based on the first model and the second model.

Abstract: A computer-implemented method is implemented in one of a Network Management System (NMS), an Element Management System (EMS), a Software Defined Networking (SDN) controller, and a server executing an SDN application, to increase capacity of one or more links in an optical network. The computer-implemented method includes determining Net System Margin comprising a metric of overall excess margin in the optical network until a Forward Error Correction (FEC) limit is reached; performing an optimization of a plurality of parameters of the optical network to determine which settings are appropriate in the optical network to provide the increased capacity and to consume at least part of the Net System Margin; and causing a plurality of modems in the optical network to change settings based on the optimization to provide the increased capacity.

Abstract: A flexible grid optical transmitter communicatively coupled to an optical network includes a coherent optical transmitter configured to generate a signal at a respective center frequency on an optical spectrum and spanning n bins about the respective center frequency, wherein n is an integer greater than 1, wherein the respective center frequency and the n bins are utilized to perform Operations, Administration, Maintenance, and Provisioning (OAM&P) functions. The respective center frequency and the n bins are specified to the coherent optical transmitter by a management system for the OAM&P functions. Each of the n bins can include a same arbitrary size, and the arbitrary size can be greater than or equal to 1 GHz and less than or equal to 12.5 GHz.

Abstract: A method of managing an optical service in a node utilizing a flexible grid for optical spectrum includes utilizing a Media Channel (MC) model to manage a portion of optical spectrum on an optical line, the MC model includes first frequency information which define the portion of optical spectrum; utilizing a Network Media Channel (NMC) model to manage the optical service and to model a path of the optical service in the MC model, the NMC model has frequency information and port connection information for the optical service; and programming hardware in the node based on the MC model and the NMC model to implement the optical service.

Abstract: A method, a controller, and an optical network element are configured to perform steps of monitoring one or more optical links each formed by optical transceivers which are configured to provide variable capacity via a plurality of modulation formats; based on the monitoring, causing corresponding optical transceivers for the one or more optical links to operate at a first modulation format different from a second modulation format providing excess capacity; and mapping the excess capacity to bandwidth useable by one or more services managed by the one or more of the management system, the management plane, and the control plane.

Abstract: A method of managing an optical service in a node utilizing a flexible grid for optical spectrum includes utilizing a Media Channel (MC) model to manage a portion of optical spectrum on an optical line, the MC model includes first frequency information which define the portion of optical spectrum; utilizing a Network Media Channel (NMC) model to manage the optical service and to model a path of the optical service in the MC model, the NMC model has frequency information and port connection information for the optical service; and programming hardware in the node based on the MC model and the NMC model to implement the optical service.

Abstract: Systems and methods include, in a controller, responsive to a request to add one or more channels to a path in an optical network which has in-service channels, determining a plurality of logical control seams to split the path, wherein the path includes a plurality of optical sections and each logical control seam has a boundary at an associated optical section; determining controller speed for each of the plurality of logical control seams based on corresponding optical margin; and performing, for each of the plurality of logical control seams, control at the determined controller speed to add the one or more channels with the in-service channels.

Abstract: Systems and methods using a bi-directional Optical Time Domain Reflectometer (OTDR) to monitor a fiber optic communication system including a first node and a second node. The systems and methods include performing a first OTDR measurement at a first OTDR wavelength at the first node on a first fiber; performing a second OTDR measurement at a second OTDR wavelength at the second node on the first fiber; and utilizing the first OTDR measurement and the second OTDR measurement for event detection on the first fiber.

Abstract: A method, a network element, and a network include determining excess margin relative to margin needed to ensure performance at a nominal guaranteed rate associated with a flexible optical modem configured to communicate over an optical link; causing the flexible optical modem to consume most or all of the excess margin, wherein the capacity increased above the nominally guaranteed rate includes excess capacity; and mapping the excess capacity to one or more logical interfaces for use by a management system, management plane, and/or control plane. The logical interfaces can advantageously be used by the management system, management plane, and/or control plane as one of restoration bandwidths or short-lived bandwidth-on-demand (BOD) connections, such as sub-network connections (SNCs) or label switched paths (LSPs).

Abstract: 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 i1, i2, i3, i4 are determined based on outputs of the plurality of detectors, the outputs i1, i2, i3, i4 are linear projections of corresponding Stokes Parameters of the input light.