A data center network system and a signal transmission system, where the signal transmission system includes one hub device, at least two switches, multiple colored optical modules, at least two multiplexers/demultiplexers, and at least two servers. The hub device, the at least two switches, the multiple colored optical modules, the at least two multiplexers/demultiplexers, and the at least two servers form a star network topology structure.

An optical add/drop system supporting a colorless, directionless, and contentionless (CDC) architecture includes a Contentionless Wavelength Selective Switch (CWSS)-based optical add/drop device including N local add/drop ports and M degree ports; and a channel pre-combiner including a common port connected to a first port of the N local add/drop ports and at least two local add/drop ports coupled to the common port. The CWSS-based optical add/drop device can include an M-array of 1?N Wavelength Selective Switches (WSSs) and an N-array of M?1 switches. The channel pre-combiner can be a passive device which passively combines the at least two local add ports and splits the at least two local drop ports. The channel pre-combiner can also include amplifiers on the common port in both an add direction and a drop direction.

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.

An Optical Add/Drop Multiplexer (OADM) node includes a plurality of degrees each having a multiplexer and a demultiplexer configured to interface to an optical section in an optical network; one or more channel holder sources configured to connect to corresponding multiplexers of the plurality of degrees and provide optical power at unoccupied portions of optical spectrum on the corresponding optical section to present a full-fill loading condition thereon; and control circuitry configured to locally detect a failure on the one or more channel holder sources affecting an upstream degree, and switch unoccupied optical spectrum filled with the channel holder signals from one or more downstream degrees to the upstream degree.

In some embodiments, a system includes a super-channel multiplexer (SCM) and an optical cross connect (OXC) switch. The SCM is configured to multiplex a set of optical signals into a super-channel optical signal with a wavelength band. The OXC switch is configured to be operatively coupled to the SCM and a reconfigurable optical add-drop multiplexer (ROADM) degree. The OXC switch is configured to be located between the SCM and the ROADM degree and the OXC switch, the SCM, and the ROADM degree are configured to be included in a colorless, directionless, and contentionless (CDC) optical network. The OXC switch is configured to switch, based on the wavelength band, the super-channel optical signal to an output port from a set of output ports of the OXC switch. The OXC switch is configured to transmit the super-channel optical signal from the output port to the ROADM degree.

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 M?N 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.

A method of automated testing and evaluation of a node of a communications network, the method comprising: a management computer interacting with the node to discover fiber trails within the node that can be safely tested; and the management computer interacting with the node to test at least continuity of each identified fiber trail that can be safely tested.

Example embodiments of the present invention relate to programmable ROADMs used to construct optical nodes. Example embodiments include wavelength switches and waveguide switches, wherein the waveguide switches may be programmed to direct wavelength division multiplexed optical signals to and from the wavelength switches.

A modular routing node includes a single input port and a plurality of output ports. The modular routing node is arranged to produce a plurality of different deflections and uses small adjustments to compensate for wavelength differences and alignment tolerances in an optical system. An optical device is arranged to receive a multiplex of many optical signals at different wavelengths, to separate the optical signals into at least two groups, and to process at least one of the groups adaptively.

An optical add/drop system supporting a colorless, directionless, and contentionless (CDC) architecture includes a Contentionless Wavelength Selective Switch (CWSS)-based optical add/drop device including N local add/drop ports and M degree ports; and a channel pre-combiner including a common port connected to a first port of the N local add/drop ports and at least two local add/drop ports coupled to the common port. The CWSS-based optical add/drop device can include an M-array of 1?N Wavelength Selective Switches (WSSs) and an N-array of M?1 switches. The channel pre-combiner can be a passive device which passively combines the at least two local add ports and splits the at least two local drop ports. The channel pre-combiner can also include amplifiers on the common port in both an add direction and a drop direction.