Abstract: An optical access network includes a first ring and a second ring communicating optical signals in opposite directions. The network also includes an access node coupled to both rings that adds traffic in a first wavelength of a first optical signal communicated on the first ring. Furthermore, the network includes a hub node coupled to each ring and coupled to an optical core network. The hub node receives the first optical signal, forwards a first copy of the signal to a first wavelength blocking unit that terminates the traffic in the first wavelength, and forwards a second copy of the signal to a first network interconnection element that forwards the traffic in the first wavelength to the core network. Furthermore, upon detection of an interruption of the traffic in the first wavelength on the first ring, the access node adds the traffic in a second wavelength of a second optical signal communicated on the second ring.

Abstract: Providing protection for a network includes establishing a light-trail through a sequence of nodes of an optical network, where the sequence of nodes is coupled by a first fiber and by a second fiber. Traffic is communicated through a plurality of connections of the light-trail, where a connection is operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes. A failure of the light-trail is detected. A protection light-trail corresponding to the light-trail is established. The traffic of the plurality of connections is communicated through the protection light-trail.

Abstract: A method and system for control signaling in an open ring optical network includes transmitting traffic in an optical ring. At each of a plurality of nodes along the ring, local traffic is passively added to and passively dropped from the connected ring. At each node, an ingress optical supervisory channel (OSC) signal is dropped from the ring to a managing element. An egress OSC signal is added to the ring from the managing element. The OSC signals may be in-band signal or out-of-band signals.

Abstract: An optical network includes at least one Level 1 network that includes a number of interconnection nodes and one or more Level 2 networks that each include one or more access nodes. The one or more Level 2 networks are each coupled to the Level 1 network via at least one interconnection node. One or more of the access nodes are each operable to add upstream traffic to the associated Level 2 network in a sub-wavelength, each sub-wavelength comprising a portion of a wavelength associated with the Level 1 network. Furthermore, one or more of the interconnection nodes are each operable to receive upstream traffic from a number of access nodes in a number of sub-wavelengths, process the upstream traffic in the sub-wavelengths as traffic in a single wavelength associated with the Level 1 network, and forward the upstream traffic from the access nodes in the single wavelength on the Level 1 network.

Abstract: An optical network is disclosed that carries optical traffic in multiplexed wavelengths between a number of nodes. The network includes at least one light-trail associated with one of the wavelengths and established between a convener node and an end node, and including one or more intervening nodes. The network also includes an out-of-band control channel that is associated with a different wavelength than the light-trail. The control channel is used to communicate control messages to establish the light-trail and to allocate use of the light-trail by the convener node and the intervening nodes. Each of the convener node, the one or more intervening nodes, and the end node is operable to receive optical traffic in a number of multiplexed wavelengths from the optical network, drop a first copy of the multiplexed optical traffic from the optical network, and forward a second copy of the multiplexed optical traffic on the optical network.

Abstract: An optical network is operable to carry optical traffic in a plurality of wavelengths between a plurality of nodes. The optical network includes a light-trail, a convener node, one or more intervening nodes, and an end node. The light-trail is established in the optical network between the convener node and the end node and couples the convener node, the intervening nodes, and the end node. Furthermore, the light-trail is associated with one of a plurality of wavelengths. The convener node and the intervening nodes are each operable to determine whether another node having a higher priority is transmitting optical traffic on the light-trail and, in response to determining that no node having a higher priority is transmitting on the light-trail, transmit optical traffic to one of the nodes in the light-trail. The convener node and the intervening nodes are each further operable to indicate to one or more nodes on the light-trail that optical traffic is being transmitted on the light-trail.

Abstract: The present invention aims at providing a method for controlling wavelength characteristics of optical transmission powers by Raman amplification, in which the wavelength characteristics of optical transmission powers are automatically compensated without giving any losses to channel lights to thereby improve transmission characteristics, and an apparatus adopting the same. To this end, the method for controlling wavelength characteristics of optical transmission powers by Raman amplification according to present invention supplies Raman pump light to an optical transmission path (Raman amplifying medium); compensates the wavelength characteristics of optical transmission powers caused by transmission of WDM signal light through the optical transmission path, by gain wavelength characteristics of generated Raman amplification; and monitors the wavelength characteristics of optical transmission powers after Raman amplification to thereby control the gain wavelength characteristics of Raman amplification.

Abstract: An optical amplification device which includes first and second optical amplifiers, and a controller. The first optical amplifier receives a light and amplifies the received light. The second optical amplifier receives the light amplified by the first optical amplifier, and amplifies the received light. When a level of the light received by the first optical amplifier changes by ?, the controller controls a level of the light received by the second optical amplifier to change by approximately ??. In various embodiments, the controller causes the sum of the gains of the first and second optical amplifiers to be constant. In other embodiments, the optical amplification device includes first and second optical amplifier and a gain adjustor. The gain adjustor detects a deviation in gain of the first optical amplifier from a target gain, and adjusts the gain of the second optical amplifier to compensate for the detected deviation.

Abstract: An optical communication system includes an optical ring, a hub node, and a plurality of local nodes. The hub node and the plurality of local nodes are coupled to the optical ring. The hub node is capable of receiving traffic over the optical ring from the plurality of local nodes on a transmitting wavelength and of transmitting traffic over the optical ring to the local nodes on a receiving wavelength. The plurality of local nodes are capable of adding traffic to and drop traffic from the optical ring and at least one local node is capable of adding traffic to the optical ring by determining whether any other local node is transmitting at the transmitting wavelength. The local node adding traffic is also capable of transmitting a request message to the hub node requesting use of the transmitting wavelength, in response to determining that no other local node is transmitting at the transmitting wavelength.

Abstract: Monitoring wavelength dispersion variation of an optical signal includes receiving the optical signal at a detector. The optical signal comprises photons of different spectrum components. The photons are received at a material of the detector. The material is operable to produce a reaction in response to the arrival of a predetermined number of photons. Reactions produced by the material in response to receiving the plurality of photons are monitored. Whether there is wavelength dispersion variation among the components is established in accordance with the reactions.

Abstract: A communication system includes in-band networks, out-of-band (OOB) networks, and translating nodes. In-band data is communicated in the in-band networks in a shared channel and routed based on a destination address specified by in-band control information that is also communicated in the same shared channel as the data. OOB data is communicated in the OOB networks in an OOB data channel and routed based on control information communicated in an OOB control channel, the OOB control channel being a different channel from the OOB data channel on which the OOB data is transmitted. Translating nodes couple the OOB networks and in-band networks and are capable of translating in-band control data and in-band control information for communication in the OOB networks. The translating nodes are also capable of translating OOB control information and OOB data for communication in the in-band networks.

Abstract: An add/drop node for an optical network comprises a passive splitter to split an ingress signal from the network into a first ingress signal and a second ingress signal. A first amplified splitter stages module is operable to passively split and amplify the first ingress signal into a plurality of drop signals. A filter module is operable to filter the second ingress signal to provide a filtered pass-through signal. A second amplified splitter stages module is operable to passively combine a plurality of add signals into a combined add signal and to combine the combined add signal with the filtered pass-through signal to create an egress signal forwardable to the network.

Abstract: A method for providing a storage area network includes receiving, at a data storage node, data from a number of storage area network (SAN) servers via associated local nodes coupled to a optical network. The data is received at a plurality of transmitting wavelengths, where each local node is assigned a different transmitting wavelength. The method also includes storing the received data at the data storage node and sending acknowledgement messages to SAN servers to indicate receipt of the data. The acknowledgement messages are sent via the local nodes at a single receiving wavelength and each local node is configured to receive this receiving wavelength. The method may also include receiving, at the data storage node, a request for data stored at the data storage node from any of SAN servers via the associated local node at the assigned transmitting wavelength of the associated local node.

Abstract: A switchgear has an insulating container filled with an insulating gas, a fixed current-carrying shaft fixed airtightly to one opening of the insulating container, a fixed contact provided on an end of the fixed current-carrying shaft in the insulating container, a movable contact configured to separably contact the fixed contact, a movable current-carrying shaft having the movable contact provided on an end and airtightly movably penetrating the other opening of the insulating container, and an operation mechanism coupled with the movable current-carrying shaft at an outside of the insulating container. The insulating container is constituted by a plurality of insulating layers, and the insulating layers are higher in dielectric constant as closer to an inside of the insulating container.

Abstract: The method and system for testing during operation of an open ring network includes opening a ring of the network at the node. Traffic circulating on the ring is dropped in the node to a monitoring element prior to or at the opening of the ring in the node. At the monitoring element, a signal received from the ring is tested. During tested and while the ring is open, traffic continues to be communicated between each node on at least one of the ring or a second ring each connecting the nodes of the network.

Abstract: A system for distributing optical signals comprises a plurality of optical splitter stages. The optical splitter stages are each operable to passively split each of one or more optical signals provided to the stage into a plurality of optical signals. At least one of the optional splitter stages comprises an amplification stage, with the amplification stage including a plurality of gain media. The gain media are each operable to amplify an optical signal with pump power.

Abstract: An optical access network includes a first ring and a second ring communicating optical signals in opposite directions. The network also includes an access node coupled to both rings that adds traffic in a first wavelength of a first optical signal communicated on the first ring. Furthermore, the network includes a hub node coupled to each ring and coupled to an optical core network. The hub node receives the first optical signal, forwards a first copy of the signal to a first wavelength blocking unit that terminates the traffic in the first wavelength, and forwards a second copy of the signal to a first network interconnection element that forwards the traffic in the first wavelength to the core network. Furthermore, upon detection of an interruption of the traffic in the first wavelength on the first ring, the access node adds the traffic in a second wavelength of a second optical signal communicated on the second ring.

Abstract: An optical network includes an optical ring capable of transmitting traffic in one of a plurality of wavelengths of an optical signal between a plurality of nodes. The nodes transmit a plurality of working traffic streams in a plurality of working wavelengths. In response to an interruption in a first working traffic stream, a node transmits, in a protection wavelength, a first protection traffic stream that is associated with the first working traffic stream. Furthermore, in response to an interruption in a second working traffic stream, a node transmits, in the protection wavelength, a second protection traffic stream that is associated with the second working traffic stream, such that the first protection traffic stream and the second protection traffic stream share, at different times, the protection wavelength.

Abstract: An optical network includes an optical ring, a plurality of local nodes, and a data center node. The plurality of local nodes are coupled to the optical ring and each local node is capable of receiving traffic from a local client and associating a transmitter tag with the traffic. The transmitter tag identifies a virtual network of the local client. The local node is further capable of transmitting the traffic on the optical ring. The data center node is also coupled to the optical ring and is capable of receiving traffic transmitted by one of the local nodes and determining a receiver tag for the traffic, based on the transmitter tag associated with the traffic and the local node that transmitted the traffic. The data center node is also capable of associating the selected receiver tag with the traffic and transmitting the traffic on the optical ring.

Abstract: A device for directing one or more optical channels includes one or more micromirror elements. A micromirror element has a mirror and a mirror controller. The mirror is operable to reflect light at a first interaction area to yield a first passband for an optical channel, and to reflect light at a second interaction area to yield a second passband for the optical channel. The mirror controller operates to position the mirror at a first position at which light interacts with the first interaction area to yield the first passband, and to position the mirror at a second position at which light interacts with the second interaction area to yield the second passband.