In wavelength division multiplexing (WDM) systems, one optical multiplexing section (OMS) can support several channels. During a network reconfiguration, the number or channel index of the channels in the OMS may change, which may result in a change in gain for other channels in the OMS due to the channel loading dependant gain properties of many optical amplifiers. Equalization is therefore required in order to reduce power excursion for the channels in the OMS. Using a model for the channel loading dependent gain of optical amplifiers, equalization may be performed more quickly than using measurement-based equalization methods. The model predicts the change in gain for the channels in an OMS following network reconfiguration, and allows for an equalizer to quickly or pre-emptively adjust for the changes. This model may include an artificial neural network, which is trained using some of the possible channel loading conditions for the OMS.

A Reconfigurable Optical Add/Drop Multiplexer (ROADM) node with a Colorless, Directionless, and Contentionless (CDC) architecture, targeting smaller degree nodes, includes an integrated ROADM degree and add/drop module having M common input and output ports and N add/drop input and output ports, wherein the integrated ROADM degree and add/drop module is formed by an MN demultiplexer Contentionless Wavelength Selective Switch (CWSS) and an MN multiplexer CWSS; and X degree modules, each having an input and output port connected to common ports of the integrated ROADM degree and add/drop module, a first set of ports of the N add/drop input and output ports are connected for degree-to-degree connectivity and a second set of ports of the N add/drop input and output ports are utilized for local add/drop, such that the integrated module provides both the degree-to-degree connectivity and the local add/drop.

The present disclosure relates to a technical field of optical communication, and more particularly to a device and method for matching optical fiber connections for ROADM service side, wherein the device comprises a reference control optical channel transmitter, a downlink WSS, a plurality of emitting ports, a reference control optical channel receiver, an uplink WSS and a plurality of receiving ports; the reference control optical channel transmitter emitting a reference control optical channel signal, and the downlink WSS emitting the reference control optical channel through the respective emitting ports in a polling manner; the reference control optical channel receiver receiving the reference control optical channel signal, and the uplink WSS selectively receiving the reference control optical channel over the plurality of receiving ports in the polling manner; wherein the reference control optical channel operating within an operating wavelength range of WSSs in the ROADM but outside a wavelength range of a service optical channel. By using WSS to control polling of the reference control optical channel among service side ports of ROADM, the present disclosure realizes an auto-routing matching of an optical fiber connection between different service side ports of ROADM and improves configuration efficiency, and at the same time, also realize to monitor performance of the optical fiber connection between service side ports of ROADMs in different directions and be a standby physical channel for chassis cascade.

Example embodiments of the present invention relate to a software programmable reconfigurable optical add drop multiplexer (ROADM) comprising of at least one MN wavelength selective switch and a plurality of programmable waveguide optical elements, wherein when the plurality of programmable waveguide optical elements are set to a first configuration, the software programmable ROADM provides wavelength switching for at least two degrees of an n-degree optical node, and wherein when the programmable waveguide optical elements are set to a second configuration, the software programmable ROADM provides wavelength switching for at least two degrees of an m-degree optical node, wherein m>n.

Systems and methods are in a node in a network utilizing a control plane for triggering mesh restoration due to intra-node faults, and include monitoring at least one channel at a degree at a plurality of degrees associated with the node; detecting a fault on the at least one channel, wherein the fault is an intra-node fault upstream of the degree; and transmitting a channel fault indicator downstream of the fault to at least one downstream node along a path of the faulted channel, wherein restoration is triggered based on the channel fault indicator.

Submarine cable branching units with fiber pair switching configured to allow any number of trunk cable fiber pairs to access the optical spectrum any number of branch cable fiber pairs. Access to a particular branch terminal is not limited to predefined subset of the trunk fiber pairs. This approach allows fewer branch cable fiber pairs to be equipped in each branching unit, reducing system cost, simplifies system planning and provides flexible routing of overall trunk cable capacity.

Systems and methods for performing connectivity verification testing and topology discovery in a reconfigurable optical add/drop multiplexer (ROADM) are provided. The ROADM can include a ROADM block having a plurality of internal ports connected to a fiber shuffle via respective optical fibers. The ROADM block includes a test signal transmitter configured to inject an outgoing test signal having a unique signature into each internal port. The outgoing test signals are out-of-band of optical data signals traversing the ROADM. The ROADM block includes a test signal monitor configured to monitor for incoming test signals at each of the internal ports. The test signal monitor is configured to validate, based on a signature of an incoming test signal received at an internal port of the ROADM block, whether a valid connection exists between the internal port and an internal port of a second ROADM block.

An optical switch module includes: N first input ports to which a signal is input; M first output ports from which a signal is output; an MN switch to include N second input ports and M second output ports, and to set a path between the second input ports and the second output ports, the second output ports coupling with the first output ports, respectively; a test-signal input port to which a test-signal is capable of being externally input; an expansion port from which one of the test-signal and the signal from any one of the first input ports is output; and an optical switch to selectively connect at least one of the test-signal and the signal from any one of the first input ports to at least one of the expansion port and any one of the second input ports, wherein both N and M are natural numbers.

An intranodal reconfigurable optical add/drop multiplexer (ROADM) fiber management apparatus, and a system employing the apparatus. The apparatus comprises a plurality of ingress optical ports, a plurality of egress optical ports, and a plurality of optical interconnections interposed between ones of the plurality of ingress optical ports and ones of the plurality of egress optical ports. Each of the plurality of ingress optical ports corresponds to one of the plurality of egress optical ports. Each one of the plurality of ingress optical ports is optically coupled by way of the optical interconnections to at least one of the plurality of egress optical ports. Each one of the plurality of egress optical ports is optically coupled by way of the optical interconnections to at least one of the plurality of ingress optical ports.

A modular optical add/drop system supporting a Colorless, Directionless, and Contentionless (CDC) architecture includes a first Contentionless Wavelength Selective Switch (CWSS)-based optical add/drop device; and one or more channel pre-combiners each having a common port with a transmit port and a receiver port, at least two local add/drop ports, components configured to combine channels between the at least two local add/drop ports and the common port, and a splitter and a combiner connected to the common port, wherein a first output of the splitter and the combiner is connected to the first CWSS-based optical add/drop device. The modular optical add/drop system can further include a second CWSS-based optical add/drop device, wherein a second output of the splitter and the combiner is connected to the second CWSS-based optical add/drop device.