An optical demultiplexer 40 includes: a plurality of optical gate switches 41a to 41n configured to transmit, when being turned on, and to block, when being turned off, a multiplexed optical signal obtained by multiplexing optical signals of a plurality of wavelengths by time-division multiplexing or wavelength-division multiplexing in addition to time-division multiplexing; and a cAWG 42 including a plurality of input ports and a plurality of output ports and configured to input the multiplexed optical signal transmitted through the optical gate switches 41a to 41n from the plurality of input ports, demultiplex the input multiplexed optical signal for each wavelength, and cycle and output the demultiplexed optical signals from the plurality of output ports in a predetermined order.

An optical demultiplexer 40 includes: a plurality of optical gate switches 41a to 41n configured to transmit, when being turned on, and to block, when being turned off, a multiplexed optical signal obtained by multiplexing optical signals of a plurality of wavelengths by time-division multiplexing or wavelength-division multiplexing in addition to time-division multiplexing; and a cAWG 42 including a plurality of input ports and a plurality of output ports and configured to input the multiplexed optical signal transmitted through the optical gate switches 41a to 41n from the plurality of input ports, demultiplex the input multiplexed optical signal for each wavelength, and cycle and output the demultiplexed optical signals from the plurality of output ports in a predetermined order.

A service modification method includes, in a node which is part of a network controlled by a control plane, routing a connection off of its home path to a current path which is at least partially disjoint from the home path and creating a reservation for the connection on the home path such that the connection can revert thereto; signaling a modification of the connection while it is on the current path; and updating the reservation based on the modification including signaling the modification to all nodes on the home path. The service modification method can further include reverting the connection to the home path with the modification. The updating can fail due to an inability to support the modification on the home path, and the service modification method can further include periodically retrying the updating the reservation based on the modification.

A service modification method includes, in a node which is part of a network controlled by a control plane, routing a connection off of its home path to a current path which is at least partially disjoint from the home path and creating a reservation for the connection on the home path such that the connection can revert thereto; signaling a modification of the connection while it is on the current path; and updating the reservation based on the modification including signaling the modification to all nodes on the home path. The service modification method can further include reverting the connection to the home path with the modification. The updating can fail due to an inability to support the modification on the home path, and the service modification method can further include periodically retrying the updating the reservation based on the modification.

A communication system includes a first optical system and a second optical system optically connected to a clamping laser and a pump laser. The first optical system includes first and second optical splitters. The first optical splitter is configured to receive a clamping laser signal from the clamping laser and split the signal into split clamping laser signals. The second optical splitter is configured to receive a pump laser signal from the pump laser and split signal into split pump laser signals. The second optical system is optically connected to the first optical system and includes amplifier systems. Each amplifier system is configured to receive a multiplexed signal. The second optical system includes first and second combiners optically connected to an erbium-doped fiber. The first combiner is optically connected to the first splitter, and the second combiner is optically connected to the second splitter.

Systems and methods for a multi-layer network to achieve network resource isolation among clients using the same server network, such as a VPN in a multi-layered network and interaction within the node, may include interaction between a server layer (e.g. L0 Photonic network) and the client layer (e.g. L1 network) that help the client layer (L1) gather information about the server-layer (L0) connection affinities. For example, the use of server layer (L0) connection affinities to construct Virtual Network Topologies (VNT) and/or network abstractions for customer traffic isolations in client layer (L1), the use of VNT to offer physical and/or logical network resource isolation for L1 customers, and provide L1 VPN services in a multi-layer environment.

Systems and methods for a multi-layer network to achieve network resource isolation among clients using the same server network, such as a VPN in a multi-layered network and interaction within the node, may include interaction between a server layer (e.g. L0 Photonic network) and the client layer (e.g. L1 network) that help the client layer (L1) gather information about the server-layer (L0) connection affinities. For example, the use of server layer (L0) connection affinities to construct Virtual Network Topologies (VNT) and/or network abstractions for customer traffic isolations in client layer (L1), the use of VNT to offer physical and/or logical network resource isolation for L1 customers, and provide L1 VPN services in a multi-layer environment.

A communication system includes a first optical system and a second optical system optically connected to a clamping laser and a pump laser. The first optical system includes first and second optical splitters. The first optical splitter is configured to receive a clamping laser signal from the clamping laser and split the signal into split clamping laser signals. The second optical splitter is configured to receive a pump laser signal from the pump laser and split signal into split pump laser signals. The second optical system is optically connected to the first optical system and includes amplifier systems. Each amplifier system is configured to receive a multiplexed signal. The second optical system includes first and second combiners optically connected to an erbium-doped fiber. The first combiner is optically connected to the first splitter, and the second combiner is optically connected to the second splitter.

An all-optical time slice switching method based on time synchronization is provided. With the method, continuous data streams in an optical network are assembled to time domain periodic optical time slices and are transmitted in an asynchronous transmission mode. Network nodes obtain high precision synchronization time via a network and control optical switches to switch arriving optical time slices to a target port at precise time points periodically, therefore all-optical switching is implemented. When a connection request arrives, an available path, a wavelength and time slots to be occupied are calculated by a source node according to information on available time slots of the optical network, and the time slots are reserved by a connection management module. After the time slots are reserved, the source node send optical time slices carrying services periodically at reserved time slots. A destination node restores the optical time slices to the data streams.

A communication system includes a first optical system and a second optical system optically connected to a clamping laser and a pump laser. The first optical system includes first and second optical splitters. The first optical splitter is configured to receive a clamping laser signal from the clamping laser and split the signal into split clamping laser signals. The second optical splitter is configured to receive a pump laser signal from the pump laser and split signal into split pump laser signals. The second optical system is optically connected to the first optical system and includes amplifier systems. Each amplifier system is configured to receive a multiplexed signal. The second optical system includes first and second combiners optically connected to an erbium-doped fiber. The first combiner is optically connected to the first splitter, and the second combiner is optically connected to the second splitter.