An exemplary apparatus is provided for an optical node of an optical ring network. The optical node comprises a main branch with a wavelength blocker configured to block at least one wavelength of signals targeted to a particular node and to permit the signals received on the other wavelength channels pass, a reception unit tuned to the at least one wavelength dedicated to signals targeted to the particular node, a first optical coupler configured to transmit the signals received from a previous node of the optical ring network both to the main branch and to the reception unit, a transmission unit configured to transmit signals to a wavelength channel according to their targeted node, and a second optical coupler configured to receive the signals received from the main branch and from the transmission unit and to transmit the received signals toward a next node of the optical ring network.

A datacenter for performing a service is provided. The datacenter is configured for receiving an optical signal comprising groups of wavelength bands, A1, A2, A3, . . . , AX, and B, X being an integer, the signal being associated with a request for a service to be executed by the datacenter, the datacenter being configured for executing the service and outputting the result of the service. The datacenter comprises at least one 1:N MD-WSS, having one common port and N tributary ports, where N is an integer and N>1, and a group of at least one server cluster, each comprising a respective transceiver configured to receive and transmit signals on at least some of the wavelength bands.

Method and apparatus of an optical routing system (ORS) capable of automatically discovering intra-nodal fiber connections using a test channel transceiver (TCT) are disclosed. ORS, in one embodiment, includes a set of reconfigurable optical add-drop multiplexer (ROADM) modules, intra-nodal fiber connections, add-drop modules, and a test module. The ROADM modules are able to transmit or receive optical signals via optical fibers. The intra-nodal fiber connections are configured to provide optical connections. The add-drop modules are able to selectively make connections between input ports and output ports. The test module containing TCT is configured to identify at least a portion of intra-nodal connections of the ROADM via a test signal operating with a unique optical frequency.

In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system includes a branching unit (BU) and a separate predetermined wavelength filter (PWF) unit. The PWF unit may include wavelength selective elements (e.g., filters) for providing a desired wavelength allocation and may also include optical connections (e.g. optical couplers) for coupling the allocated wavelengths between trunk and branch paths in the WDM system. The PWF unit is physically separate from an associated BU but coupled adjacent the BU.

In order to prevent a signal which a terminal station does not require from being intercepted by the terminal station without greatly changing the power of optical signals to be transmitted from a node to the terminal station, a node device is provided with: a first optical unit which outputs a first optical signal received from a first terminal station and addressed to a second terminal station, and a second optical signal received from the first terminal station, addressed to a third terminal station, and having a different wavelength band from the first optical signal; and a second optical unit to which the first and second optical signals outputted from the first optical unit are inputted, and which shifts the frequency of the first optical signal by a predetermined amount to create a fourth optical signal, passes the second optical signal without any change, couples the second and fourth optical signals, and transmits a resultant signal to the third terminal station.

An optical add-drop multiplexer and a branching unit are provided, where implementation of the optical add-drop multiplexer includes: an optical processing component, a first combining device, a second combining device, and a second scrambler, where the optical processing component includes an input end, a first output end, a second output end, and a third output end; the first output end of the optical processing component is connected to a first input end of the second combining device, and the second output end of the optical processing component is connected an input end of the second scrambler; an output end of the second scrambler is connected to a second input end of the second combining device; and the third output end of the optical processing component is connected to a first input end of the first combining device.

An optical switch, comprising: a first optical waveguide, a first optical add path, a second optical add path and a micro-ring resonator. The micro-ring resonator is operable to add a first optical signal at a preselected wavelength received from the first optical add path to the first optical waveguide to travel in a first direction through the first optical waveguide. The micro-ring resonator is further operable to add a second optical signal at the preselected wavelength received from the second optical add path to the first optical waveguide to travel in a second direction through the first optical waveguide opposite to the first direction. There is also provided an optical drop switch, an optical switching apparatus, an optical communications network node and an optical communications network.

Systems and methods for routing wavelengths in an optical network include responsive to a path request for a wavelength or group of wavelengths, determining a path through the optical network; determining a location on the path where wavelength blocking should occur to form a loop-free path in the optical network; and setting the wavelength blocking at the location. The optical network can utilize a broadcast and select architecture and the wavelength blocking is configured to prevent the wavelength or group of wavelengths from looping back on a port where the wavelength or group of wavelengths has already been received on. The optical network can utilize an all-broadcast architecture and the wavelength blocking is configured to prevent multiple paths for the wavelength or group of wavelengths by constraining the wavelength or group of wavelengths to a single path through the optical network.

An optical switch, comprising: a first optical waveguide, a first optical add path, a second optical add path and a micro-ring resonator. The micro-ring resonator is operable to add a first optical signal at a preselected wavelength received from the first optical add path to the first optical waveguide to travel in a first direction through the first optical waveguide. The micro-ring resonator is further operable to add a second optical signal at the preselected wavelength received from the second optical add path to the first optical waveguide to travel in a second direction through the first optical waveguide opposite to the first direction. There is also provided an optical drop switch, an optical switching apparatus, an optical communications network node and an optical communications network.

The invention relates to a method for auto-configuring a wavelength selective switch (WSS) device having an output port and a plurality of input ports and coupled to a WSS controller. When connected to a WDM optical network, the WSS controller is programmed to utilize one or more optical channel monitors (OCM) coupled to the input and/or output ports to detect which of the wavelengths are present at the input ports. Wavelengths that are not detected on any input port are blocked by the WSS. Any wavelength detected as present at one and only one input port is switched by the WSS to the output port. If a wavelength is detected at two or more input ports, it is either blocked by the WSS at each of the input ports until user intervention, or is blocked at all but one of the input ports as defined by assigned port priorities.