Device cost and electric power consumption are reduced. Nodes 11a to 11d as optical add/drop multiplexers each include cAWGs 24a and 24b that include a plurality of first side ports and a plurality of second side ports connected between light transmission paths as optical fibers 12 and 13 and transponders 25a to 25n and in which a first optical signal input-output channel interval of each port is a plurality of times larger than a second optical signal input-output channel interval of ports of the transponders 25a to 25n and optical signals of a plurality of different wavelengths from one or a plurality of transponders 25a to 25n or the light transmission paths can pass through a first channel. The cAWGs 24a and 24b cause the optical signals from the transponders 25a to 25n to pass through the first side ports, and then cyclically outputs and transmits the optical signals through the plurality of second side ports in a predetermined order to the light transmission paths. The optical signals transmitted through the light transmission paths are caused to pass through the second side ports and then output from the plurality of first side ports in a predetermined order to the transponders 25a to 25n.

Device cost and electric power consumption are reduced. Nodes 11a to 11d as optical add/drop multiplexers each include cAWGs 24a and 24b that include a plurality of first side ports and a plurality of second side ports connected between light transmission paths as optical fibers 12 and 13 and transponders 25a to 25n and in which a first optical signal input-output channel interval of each port is a plurality of times larger than a second optical signal input-output channel interval of ports of the transponders 25a to 25n and optical signals of a plurality of different wavelengths from one or a plurality of transponders 25a to 25n or the light transmission paths can pass through a first channel. The cAWGs 24a and 24b cause the optical signals from the transponders 25a to 25n to pass through the first side ports, and then cyclically outputs and transmits the optical signals through the plurality of second side ports in a predetermined order to the light transmission paths. The optical signals transmitted through the light transmission paths are caused to pass through the second side ports and then output from the plurality of first side ports in a predetermined order to the transponders 25a to 25n.

A fault location in an optical cable at a long distance is easily measured and detected with low-cost equipment in a configuration in which an isolator is disposed in the vicinity of an optical amplifier for improved optical transmission performance and for stabilization. An optical amplifier has a configuration in which multiplexing/demultiplexing units as first WDM filters and that multiplex/demultiplex main signal light and OTDR light and (measurement light) for submarine cable fault measurement transmitted to a submarine cable in opposite directions from a transmission device side and a reception device side, transmit the multiplexed/demultiplexed main signal light to a main path passing through an isolators and an EDF, and transmit the multiplexed/demultiplexed OTDR light to a bypass path bypassing the isolators and the EDF are included on both sides of a set of the isolators and the EDF of the submarine cable.

Provided is an optical transceiver including: an optical transmitter configured to sequentially generate a plurality of optical transmission signals each including transmission wavelength information and output the plurality of optical transmission signals to a connected multiplexer/demultiplexer; and a controller configured to generate the transmission wavelength information for each of the plurality of optical transmission signals.

Implementations described and claimed herein provide systems and methods for a configurable optical peering fabric to dynamically create a connection between participant sites without any physical site limitations or necessity of specialized client and network provider equipment being located within such a facility. Client sites to a network may connect to a configurable switching element to be interconnected to other client sites in response to a request to connect the first client site with a second site, also connected to network, via the switching element. A request may trigger verification of the requested and, upon validation, transmission of an instruction to the switching element to enable the cross connect within the switching element. The first site and the second site may thus be interconnected via the switching element in response to the request, without the need to co-locate equipment or to manually install a jumper between client equipment.

Methods and apparatus are provided for switching an optical signal. In one aspect, an optical switching apparatus comprises a first beam splitting apparatus configured to split a first optical input signal into first and second optical signals, wherein the first optical signal has substantially the same polarization state as the second optical signal. The apparatus also comprises a switching matrix comprising a plurality of first outputs of the switching matrix and a plurality of second outputs of the switching matrix, each first output of the switching matrix associated with a respective one of the second outputs of the switching matrix, the switching matrix configured to selectively direct the first optical signal to a selected one of the first outputs of the switching matrix and to selectively direct the second optical signal to the second output of the switching matrix associated with the selected first output of the switching matrix. The apparatus further comprises a plurality of beam combining apparatus, each beam combining apparatus configured to combine optical signals from a respective one of the first outputs of the switching matrix and its associated second output of the switching matrix.

Optical transmission device is provided in one of a plurality of nodes in an optical network. Different carrier frequencies are respectively allocated to the plurality of nodes. The optical transmission device includes: transmitter, splitter and receiver. The transmitter generates a first subcarrier optical signal with a first subcarrier established on a low-frequency side of a first carrier frequency and a second subcarrier optical signal with a second subcarrier established on a high-frequency side of the first carrier frequency. The splitter splits an optical signal including the first subcarrier optical signal and the second subcarrier optical signal. The output of the splitter is guided to first and second adjacent nodes. The receiver recovers data carried by the first subcarrier and data carried by the second subcarrier from received optical signal. A difference between carrier frequencies of adjacent nodes corresponds to a bandwidth of the subcarrier.

Implementations described and claimed herein provide systems and methods for a configurable optical peering fabric to dynamically create a connection between participant sites without any physical site limitations or necessity of specialized client and network provider equipment being located within such a facility. Client sites to a network may connect to a configurable switching element to be interconnected to other client sites in response to a request to connect the first client site with a second site, also connected to network, via the switching element. A request may trigger verification of the requested and, upon validation, transmission of an instruction to the switching element to enable the cross connect within the switching element. The first site and the second site may thus be interconnected via the switching element in response to the request, without the need to co-locate equipment or to manually install a jumper between client equipment.

Implementations described and claimed herein provide systems and methods for a configurable optical peering fabric to dynamically create a connection between participant sites without any physical site limitations or necessity of specialized client and network provider equipment being located within such a facility. Client sites to a network may connect to a configurable switching element to be interconnected to other client sites in response to a request to connect the first client site with a second site, also connected to network, via the switching element. A request may trigger verification of the requested and, upon validation, transmission of an instruction to the switching element to enable the cross connect within the switching element. The first site and the second site may thus be interconnected via the switching element in response to the request, without the need to co-locate equipment or to manually install a jumper between client equipment.

A communication device that is connected to a wavelength-multiplexed optical ring network and conducts communication by performing time-division multiplexing on an optical signal for each wavelength includes: a communication unit that transmits a requested transmission amount for requesting a transmission band to a master communication device, and receives an allowed transmission amount for allocating a transmission band from the master communication device; and a control unit that estimates a band utilization rate of each wavelength on the basis of the requested transmission amount and the allowed transmission amount, and allocates data to the respective wavelengths so as to equalize the band utilization rates among the wavelengths. Thus, it is possible to equalize band utilization rates among wavelengths, and enhance communication efficiency of the entire system.