An optical network communication system utilizes a passive optical network including an optical hub having an optical line terminal, downstream transmitter, an upstream receiver, a processor, and a multiplexer. The upstream receiver includes a plurality of TWDMA upstream subreceivers. The system includes a power splitter for dividing a coherent optical signal from the optical hub into a plurality of downstream wavelength signals, a long fiber to carry the coherent optical signal between the optical hub and the power splitter, and a plurality of serving groups. Each serving group includes a plurality of optical network units configured to (i) receive at least one downstream wavelength signal, and (ii) transmit at least one upstream wavelength signal. The system includes a plurality of short fibers to carry the downstream and upstream wavelength signals between the power splitter and the optical network units, respectively. Each upstream subreceiver receives a respective upstream wavelength signal.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

This disclosure describes devices and methods related to multiplexing optical data signals. A method may be disclosed for multiplexing one or more optical data signals. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to one or more wave division multiplexer (WDM). The method may comprise combining, by the one or more WDM, the combined one or more optical data signals and one or more second optical data signals, and outputting an egress optical data signal comprising the combined one or more optical data signals and one or more second optical data signals.

A node configured to operate in an optical network includes P switching planes interconnected by an SS cross-plane switch, P>1; and N.sub.i degrees per switching plane P.sub.i where i=1 to P, each degree formed by corresponding degree components having R ports, wherein a first set of ports of the R ports is for intra-plane switching, a second set of ports of the R ports is for inter-plane switching, and a third set of ports of the R ports is for in-plane add/drop. S is greater than or equal to a sum of a number of degrees across all of the P switching planes. R is greater than or equal to a sum of the first set of ports, the second set of ports, and the third set of ports.

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 are provided for enabling degree-to-degree protection within an optical node, such as an Optical Add/Drop Multiplexer (OADM) node or Reconfigurable Optical Add/Drop Multiplexer (ROADM) node. According to an exemplary protection method, a step is executed for configuring two degree-to-degree fiber links between a first degree of the OADM node and a second degree of the OADM node. The method also includes designating a first degree-to-degree fiber link of the two degree-to-degree fiber links as a primary fiber link. Also, the method includes designating a second degree-to-degree fiber link of the two degree-to-degree fiber links as a protection fiber link configured for providing protection if a fiber break is detected on the primary fiber link.

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 frequency and plurality of bins.

An apparatus includes a tail-end optical switch configured to be coupled to a broadcast star network that couples the tail-end optical switch to a head-end optical switch by a primary bidirectional optical path and a second bidirectional optical path. The tail-end optical switch having a first optical switch and a second optical switch configured to provide active switching.

A satellite payload system is presented. The system includes plurality of optical processing modules, including a plurality of ring-connected optical processing modules and at least one inter-satellite optical processing module, and at least one optical fiber ring communicatively coupled to each of the ring-connected optical processing modules. At least one of the ring-connected optical processing modules is configured to provide on-board signal processing of signals conveyed on the at least one optical fiber ring. At least one of the ring-connected optical processing modules is communicatively coupled to a respective inter-satellite optical processing module. Each inter-satellite optical processing module is configured to optically communicatively couple to a respective remote satellite.

A satellite payload system is presented. The system includes plurality of optical processing modules, including a plurality of ring-connected optical processing modules and at least one inter-satellite optical processing module, and at least one optical fiber ring communicatively coupled to each of the ring-connected optical processing modules. At least one of the ring-connected optical processing modules is configured to provide on-board signal processing of signals conveyed on the at least one optical fiber ring. At least one of the ring-connected optical processing modules is communicatively coupled to a respective inter-satellite optical processing module. Each inter-satellite optical processing module is configured to optically communicatively couple to a respective remote satellite.