A WSS is provided. The WSS includes a first common port, a second common port, a grating, a spatial light modulator, and a plurality of branch ports. The first common port is configured to receive a first-band optical signal, and the second common port is configured to receive a second-band optical signal. The grating is configured to perform wavelength demultiplexing on the first-band optical signal and the second-band optical signal, to output a plurality of first optical signals, where the first optical signals are optical signals of a single wavelength.

[PROBLEM TO BE SOLVED] To uninterruptedly change a band of an optical transmission path in a line IF section, which relays a signal transmitted to an optical transmission path in a client IF section to which a communication terminal is connected, to the same band as a changed band in the client IF section without suspending the communication in the line IF section. [SOLUTION] An optical transmission system 10A performs processing for changing a band of an optical fiber 15 in a line IF section (L section) that relays a signal from an optical fiber 12 in a client IF section (C section) to the same band as that in the C section. Line IF units 24A and 24B provided on both sides of the L section set a temporary evacuation lane p as an optical lane having a band different from those of a plurality of optical lanes 0 to n in the optical fiber 15 in the L section, selects either a change-target optical lane (for example, the optical lane 0) or the temporary evacuation lane p, the change-target optical lane being provided in the optical fiber 15 in the L section and having a band to be changed to a same band as a band in the C section, while causing a buffer unit 46 to absorb a delay difference between a signal received by the change-target optical lane and a signal received by the temporary evacuation lane p, and sets the optical lane not selected to have the same band as the band in the C section.

An apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to partition a set of ports of an optical multiplexer into a set of port groups including a first port group having a first set of ports and a second port group having a second set of ports mutually exclusive from the first set of ports. The processor is configured to associate the first port group with a first router and associate the second port group with a second router. When the optical multiplexer is operatively coupled to the first router and the second router, the first router is operatively coupled to the optical multiplexer via the first set of ports and not the second set of ports, and the second router is operatively coupled to the optical multiplexer via the second set of ports and not the first set of ports.

An optical buffer and a method for storing an optical signal using the optical buffer, where the optical buffer includes a first waveguide, a first optical delay waveguide loop and a controller. The first waveguide includes a first arm and a second arm, where a first end of the first arm is an input end of the optical buffer, and a second end of the second arm is an output end of the optical buffer. A second end of the first arm connects to a first end of the second arm. The first optical delay waveguide loop connects to the first arm at a first end using a first optical switch, and a second part of the first optical delay waveguide loop connects to the second arm at a second end using a second optical switch. The controller connects to the first optical switch and the second optical switch respectively.

An optical data center network system including multiple tier-1 optical switches, multiple tier-2 optical switches and multiple tier-3 optical switches is provided. A pod is formed by the tier-1 optical switches connected to each other through ribbon fibers. A macro pod is formed by the tier-2 optical switches connected to each other through ribbon fibers, and each of the tier-2 optical switches is connected to all of the tier-1 optical switches in one pod. The tier-3 optical switches are connected to each other through ribbon fibers, and each of the tier-3 optical switches is connected to all of the tier-2 optical switches in one macro pod. Each optical switch in each tier is implemented by using the Wavelength Selective Switch (WSS) as a basic element, which has been commercialized numerously.

A large-scale switching system deployed as a global network or a large-scale data center includes a large number of access nodes (edge nodes) interconnected through optical or electronic rotators. The rotators are logically arranged in a matrix and each access node has a channel to each rotator in a respective row and a channel from each rotator of a respective column of the matrix. A dual timing circuit coupled to a diagonal rotator pair exchanges timing data with edge nodes connecting to the diagonal rotator pair to facilitate temporal alignment of data received at input ports of each rotator. Each access node has a path to each other access node traversing only one of the rotators. The rotators may be arranged into constellations of collocated rotators to facilitate connectivity of access nodes to rotators using wavelength-division-multiplexed links.

An apparatus includes an input port group, which includes multiple input slots, and multiple input ports are provided in each input slot. An input allocation matrix includes multiple first optical switches, and an input port of the first optical switch is connected to an input port of the input slot. A cross-connect matrix includes multiple second optical switches, and an output port of the first optical switch is connected to an input port of the second optical switch. An output allocation matrix includes multiple third optical switches, and an input port of the third optical switch is connected to an output port of the second optical switch. An output port group includes multiple output slots, multiple output ports are provided in each output slot, and an output port of the output slot is connected to an output port of the third optical switch.

The invention discloses a communication method includes: receiving, by the ONU by using the first port or the second port, a wavelength switching request message delivered by the OLT, where the wavelength switching request message carries second wavelength channel information and port information that is of the second port; switching, by the ONU, an operating wavelength channel of an optical module connected to the second port from a first wavelength channel to a second wavelength channel corresponding to the second wavelength channel information; and sending, by the ONU, a wavelength switching complete message to the OLT by using the first port. According to the communication method provided in embodiments of the present invention, quick wavelength switching is performed based on the second port, so that a service is not interrupted in a wavelength switching process, and user experience is better.

Example embodiments of the present invention relate to optical wavelength directing devices used to construct compact optical nodes.

There is provided an optical transmission control device includes a memory, and a processor coupled to the memory and the processor configured to aggregate information of candidacy sections having a possibility that communication is discontinued among wavelength-multiplexed transmission sections, classify, based on the aggregated information, optical paths set between optical transmission devices into a first optical path on which, when communication in the candidacy sections is discontinued, an optical signal is not transmitted, and a second optical path on which, when the communication in the candidacy sections is discontinued, an optical signal is transmitted, and determine a wavelength allocation in a first wavelength group of the first optical path and a second wavelength group of the second optical path so that a difference in gain wavelength characteristics of the first optical path and the second optical path is equal to or less than a predetermined level.