Abstract: An optical network terminal (ONT) battery backup unit (BBU) battery voltage alert system (BVAS). This alert is provided as a supplement to an audio alarm which sounds when the backup battery is discharging because that alarm may not be heard in sufficient time if the alarm is remotely located relative to its customer, e.g., in the customer's basement or outside. A battery monitoring facility, located in a telecommunication service provider's centralized serving office, or remotely located elsewhere, monitors the voltage of each of a plurality of batteries deployed in customers' premises within the geographical area served by that centralized serving office. That battery monitoring facility receives packets via a communication network from each such customer's premises, each of those packets representing a battery voltage measurement. That battery monitoring facility stores these on-going measurements thereby creating a trending database to point to any potential future battery failures.

Abstract: Between photonic cross connects (PXCs) 3 and 4, an in-use system path passing through transmission apparatus (WDMs) 5 and 7 are set, and a backup system passing through transmission apparatus (WDMs) 6 and 8 is set. The WDMs 3 and 4 link to the PXCs 5 and 7 and release masking therebetween when the in-use system path is set, and set masking therebetween when the in-use system path is deleted. The WDMs 5 and 7 included in the in-use system path transmit an alarm to a monitoring system when an input light is turned off, and the WDMs 6 and 8 included in the backup system path do not transmit an unintended alarm to the monitoring system even when the input light is turned off.

Abstract: The present invention provides an automatic power restoring method capable of reliably detecting continuity by the dissolution of a line fault, to restore the optical power, even in a structure including an optical amplification medium on an optical transmission path and an optical communication system using the method. To this end, in an optical communication system to which the automatic power restoring method of the invention is applied, a pilot signal having a low transmission rate, a wavelength of which is set based on loss wavelength characteristics obtained by combining loss wavelength characteristics of an optical fiber used for the optical transmission path and loss wavelength characteristics of the optical amplification medium on the optical transmission path, is transmitted and received between an optical transmitting station and an optical receiving station when a line fault occurs, and a detection of continuity is thus performed.

Abstract: Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures in optical networks are described. One embodiment is a method for allocation of protection paths after a failure in an optical network. The method comprises, responsive to a failure in an active lightpath, switching traffic on the active lightpath to a protection path; subsequent to the switching, identifying all active lightpaths in the network that no longer have an available protection path; and attempting to allocate a protection path to each of the identified active lightpaths.

Abstract: The present invention provides an optical signal quality monitoring circuit and an optical signal quality monitoring method for measuring correct optical signal quality parameters when a signal bit rate is changed. The optical signal quality monitoring circuit which samples and converts an electrical signal converted from an optical signal with a given repeated frequency f1 to digital sampling data through an analog to digital conversion, thereafter, evaluates an optical signal quality parameter of the optical signal by subjecting sampling data to electrical signal processing in an integrated circuit in which a signal processing function is programmed, receives a control signal notifying that the bit rate of the optical signal is changed, or detects that the bit rate of the optical signal is changed to correct optical the signal quality parameter of the optical signal corresponding to the signal bit rate of the optical signal which is changed.

Abstract: An optical transmission-path fault-detection system for detecting a fault in an optical-transmission path connecting an optical communications apparatus and an optical amplifier corresponding to the communications apparatus is disclosed.

Abstract: A method and apparatus for restoration of operating conditions of a WDM optical ring network comprising a plurality of amplifiers linked together in a ring after a break or fault has occurred in the network. The method comprises in response to repair of the break or other fault, increasing output power or/and pump power of an amplifier in the network such that the output power or/and pump power increases substantially in accordance with a ramp function.

Abstract: A system for delivering optical signals to and from an undersea optical cable may include a cable landing station connected to the undersea optical cable and configured to convey a wavelength division multiplexed optical signal from the undersea optical cable. The system may also include a point of presence that includes wavelength division multiplexing equipment configured to convert the wavelength division multiplexed optical signal to a number of optical channels. At least one terrestrial optical fiber may be coupled between the cable landing station and the point of presence to transport the wavelength division multiplexed optical signal from the cable landing station to the point of presence.

Abstract: A wavelength division multiplexed self-healing passive optical network using a wavelength injection method includes a central office for coupling modulated multiplexed optical signals (MMOS) and broadband optical signals (BOS)for an upstream light source into one signal transmitted to a plurality of optical network units (ONUs) through a working main fiber and a protection main fiber. A remote node connects to the central office via the main fiber and protection main fiber and to the ONUs through working distribution fibers and protection distribution fibers. The remote node demultiplexes the MMOS and the (BOS) for an upstream light source. The remote node transmits demultiplexed signals to the ONUs, which receive the modulated optical signals and the BOS for an upstream light source which corresponds to predetermined ONUs, and demodulate the modulated optical signals, and modulate upstream optical signals via demultiplexed BOS for an upstream light source.

Abstract: A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

Abstract: A method and system for network wide fault isolation in an optical network are described. A single fault in a network can produce a large number of alarms at different points in an optical network. The described method and system identify the root cause alarm while masking all correlated alarms. In the embodiment of the invention, the method and system are based on a wavelength tracker technology allowing identification and tracking of individual channels in the optical network.

Abstract: A transmission apparatus that receives an optical signal by selecting any one of a plurality of provided optical signal transmission paths through protection control is configured to include a plurality of optical signal outputting sections that output the optical signals transmitted through said optical signal transmission paths respectively as optical signals having wavelengths that are different from each other, a wavelength selective optical switch capable of selectively outputting light of a wavelength corresponding to any one of the optical signals coming from the optical signal outputting sections on the basis of the frequency of a controlling frequency signal, and an optical switch controlling section that supplies said controlling frequency signal to the wavelength selective optical switch so as to output the optical signal coming from the optical signal transmission path side that is selected by said protection control among the optical signals coming from the optical signal outputting sections.

Abstract: A light receiver has a photoelectric conversion circuit which converts an input optical signal into an electrical signal, an electric amplifier which amplifies the electrical signal output from the photoelectric conversion circuit, a threshold adjustment circuit which outputs a threshold value according to signal information in the optical signal, and an optical signal loss detection circuit which compares amplitude of the electric signal output from the electric amplifier with the threshold value output from the threshold adjustment circuit and outputs results of the comparison.

Abstract: An embodiment of the invention provides a method and apparatus for restoring a connection in a network. The connection is typically a sub network connection (SNC). In an embodiment, a failed line in a link connecting a first node and a second node is detected, where the failed line is associated with a sub network connection (SNC). The sub network connection (SNC) is then mapped to an alternate line in the link. The first node will change cross connections in a switch fabric in the first node, while the second node will change cross connections in a switch fabric in the second node, so that both nodes can transmit data on the selected alternate line, in order to restore the SNC.

Abstract: An Ethernet passive optical network (EPON) ring for providing protection against fiber failures. The optical network unit (ONU) is coupled to the ring fiber by a three-port passive optical splitting module that has three two-way optical passages. By the three two-way optical passages, the OUN receives/transmits data from/to the two ends of the optical line termination (OLT) to provide protection while the fiber failure. Moreover, it provides better authorization of users and simpler collision detection by the two-way transmission of the three-port passive optical splitting module to prevent hackers from invading and to reduce collisions.

Abstract: A modular cross connect system for optical telecommunication networks has the optical unit divided in at least two main bodies with one section for connection comprising the collimators and a main commutation section with MEMS devices. The first section is a fixed part while the second section is a readily removable section. The two sections face each other through a window and, in the first section, optics are provided for steering all or part of the optical signals from and to the main MEMS unit to a MEMS standby or protection plane to allow replacement of the main MEMS unit without interrupting service.

Abstract: A method and system provide capacity-efficient restoration within an optical fiber communication system. The system includes a plurality of nodes each interconnected by optical fibers. Each optical fiber connection between nodes includes at least three channel groups with different priority levels for restoration switching in response to a connection failure. The system maintains and restores full-capacity communication services by switching at least a portion of the channel groups from a first optical fiber connection to a second optical fiber connection system based on the priority levels assigned to the channel groups. Service reliability is effectively maintained without incurring additional costs for dedicated spare optical fiber equipment by improving idle capacity utilization.

Abstract: Five electronic control units (ECU) control vehicle devices using CAN protocol. Each of ECUs is provided with a resistor and a switch for activating the resistor. A first and fifth ECUs are arranged on the leftmost and rightmost ends. Resistors of the first and fifth ECUs are used as terminating resistors to a two-wire communications line. When the two-wire communications line is broken, the first ECU sends a test signal while other ECUs excluding the fifth ECU turn on the switches from right to left. When the test signal can be received, a broken point is located on the right side of ECU that turns on its switch at this time. Thereafter ECUs on the left side of the broken point conduct communication.

Abstract: A joint “packet-optical” layer restoration mechanism protects against single, packet-layer router failures by managing network resources from both the packet layer and the optical transport layer in a synergistic manner. It reuses packet-layer router service-ports and/or transport-layer service wavelengths associated with optical switch-ports instead of reserving additional standby packet-layer router service-ports. It can reuse resources from primary paths that are unaffected by router failures and paths that exist for link-failure protection at the optical layer. Embodiments feature a modified node structure that includes both an IP router and a dynamically reconfigurable OXC, which dynamically establishes connectivity between IP-router ports and transport-layer optical fibers. The joint-layer router provides fine-granularity grooming at the IP layer and full-fledged wavelength networking via dynamic wavelength switching and/or wavelength translation at the optical layer.

Abstract: Method and apparatus for implementing a protection scheme for switched networks, and particularly GMPLS networks are described. One embodiment is a method of reserving communications channels comprising an alternative path through a switched network, the network comprising a plurality of nodes interconnected by links, wherein each link comprises at least one communications channel. The method comprises simulating failure of a first link; noting a second link over which traffic on the first link is rerouted in the event of failure of the first link; and transmitting a protection request message (“PRM”) from the first link to the second link to request reservation of a specified number of communication channels on the second link.

Abstract: A method of communicating for a communication apparatus, which includes: a terminal apparatus transmitting the information frames to a central office apparatus; the central office apparatus receiving the information frames and obtaining the terminal apparatus information from the information frames; the central office apparatus processing the information frames transmitted from the terminal apparatus, using the terminal apparatus information obtained from the information frames; whereby communication between the central office apparatus and the terminals of different vendors is implemented.

Abstract: In an optical transmitting or receiving apparatus, a plurality of replaceable electro-optic converters or a plurality of replaceable opto-electric converters are provided in correspondence with optical transmission lines.

Abstract: The disclosure is directed toward an optical transmission system comprising a primary path disposed between a first end and a second end. The primary path is configured to transmit optical signals between the first end and the second end. A secondary path is disposed between the first end and the second end. The secondary path is configured to transmit optical signals between the first end and the second end, e.g., in the event of a break in the primary path. A first variable ratio coupler is coupled to the primary path and the secondary path between the first end and the second end. The first variable ratio coupler is configured to adjust a coupling ratio between the primary path and the secondary path.

Abstract: An optical network includes a plurality of subnets. The subnets each include a plurality of add/drop nodes coupled to the optical ring and operable to passively add and drop traffic to and from the optical ring. The network further includes a plurality of gateway nodes. The gateway nodes are each coupled to the optical ring at a boundary between neighboring subnets and operable to selectively pass and terminate wavelengths between subnets to allow wavelength reuse in the subnets and to provide protection switching.

Abstract: Multiple working paths are established on each working rings and multiple protection paths are established on each of multiple protection rings. A working path on a first working ring spans across first and second nodes for signal transmission in a first direction of the ring, and a working path on a second working ring spans across the first and second nodes for signal transmission in a second, opposite direction of the ring. A protection path on a first protection ring spans across the first and second nodes for signal transmission in said second direction, and a protection path on a second protection ring spans across the first and second nodes for signal transmission in said first direction. The first and second nodes normally use the working paths, respectively. When one of the working paths fails, the first and second nodes use a corresponding protection path.

Abstract: A method for merging protection switching messages in an optical network enables a control of the amount of message bandwidth used for sending protection switching messages. A method for performing protection switching in an optical network does so in an optimal manner by performing the protection switching actions in the various nodes of a protection path in parallel rather than in sequence. To do so, a channel failure message is transmitted from an end node A in the optical network upon detecting a failure in a link in the optical network that includes the end node A. If a failure can be detected at both end nodes, the channel failure messages are transmitted from both end nodes the moment they detect failure without any further waiting. Upon receiving the first channel failure message regardless its originating end node, switching actions in intermediate nodes are initiated.

Abstract: When a primary failure occurs, each agent device (information processing device) checks itself to determine whether non-notification setting has been performed for alarm notification of the primary failure. If no non-notification setting has been performed, the agent device sends the alarm notification to a manager device (network management device). At the same time, the agent device sends a set alarm mask request to the agent device located downstream in the signal flow to request to perform non-notification setting for alarm notification of a secondary failure caused by the primary failure.

Abstract: A network component (3d) for an optical network (1) is described, including a coupling device (2; 4, 5) for optical coupling of the network component (3d) to the optical network (1), the coupling device (2; 4, 5) having a receiving module (4) and a transmitting module (5); a first data processing device (8, 9) which is unidirectionally connected to the receiving module (4); a second data processing device (10, 11) which is unidirectionally connected to the transmitting module (5); the first data processing device (8, 9) being unidirectionally connected to the second data processing device (10, 11) for transmitting data to the second data processing device; a detection device (4) for detecting the network status; and a two-way switch (23) for switching of the input of the first data processing device (8, 9) between the receiving module (4) and the output (19) of the second data processing device (10, 11) as a function of the network status detected.

Abstract: A protection arrangement for an optical switching system includes protection switching for switch planes in the optical core and for ports in the tributary cards. For a multiple layer switch core protection is also provided between layers. A first layer is for switching optical channels. The protection switches used may be 1×N, 2×N or 3×N MEMS optical switches. The 1×N MEMS provides for protection switching. The 2×N MEMS provides protection switching and testing capability. The 3×N MEMS provides for protection switching, testing and backup of the protection switching. Application of these protection switches is shown in lambda plane switch cores, multiple layer switch cores and combined switch cores.

Abstract: A method and system for providing tandem protection in a communication system. Path protection is provided using at least two redundant communication paths and selecting the communication path having a higher signal quality. Interface protection is provided through a protection transceiver. The interface protection may be delayed while the path protection attempts to restore communication.

Abstract: A performance management unit manages a primary interface and a standby or secondary interface to two channels of an optical communications network having APS capabilities. Each performance parameter is associated with three counters. First and second counters are linked to registers of the primary and the secondary ports, and the third counter is linked to the registers of the currently active port. When a protection switch occurs, the first and second counters are immediately read and reset. The third counter continues accumulating data, but becomes associated with the new active port. At the end of a read interval, the third counter correctly reflects the number of data received, regardless of switchovers between the primary and secondary channels.

Abstract: A link based network protection path calculation mechanism wherein a protection route is calculated that is guaranteed not to traverse the link it is intended to protect. The mechanism takes advantage of the fact that the same color cannot pass twice through the same optical fiber. The protection path is determined by eliminating all colors from the logical topology of the network except for the color corresponding to the link to be protected before executing the search algorithm. This serves to guarantee that the protection path calculated will not traverse the same physical fiber as the link to be protected. Virtual colors can be assigned to the links running through fiber bundles such that they do not pass through the same fiber/bundle twice.

Abstract: A method and a system for re-establishing the connection of a network device with a network, using viral communication, are provided. According to the various embodiments, a disconnected network device acts as a simple wireless device and contacts a neighboring network device to obtain configuration information. The request can be forwarded to a network management station (NMS) through one or more neighbors of the disconnected network device. Connectivity is obtained by executing the configuration instructions obtained from the NMS.

Abstract: An all optical network for optical signal traffic has at least a first ring with at least one transmitter and one receiver. The first ring includes a plurality of network nodes. At least a first add/drop broadband coupler is coupled to the first ring. The broadband coupler includes an add port and a drop port to add and drop wavelengths to and or from the first ring, a pass-through direction and an add/drop direction. The first add/drop broadband coupler is configured to minimize a pass-through loss in the first ring and is positioned on the first ring.

Abstract: A system for delivering optical signals to and from an undersea optical cable may include a cable landing station connected to the undersea optical cable and configured to convey a wavelength division multiplexed optical signal from the undersea optical cable. The system may also include a point of presence that includes wavelength division multiplexing equipment configured to convert the wavelength division multiplexed optical signal to a number of optical channels. At least one terrestrial optical fiber may be coupled between the cable landing station and the point of presence to transport the wavelength division multiplexed optical signal from the cable landing station to the point of presence.

Abstract: A communication device for interconnection of first and second networks, of which at least the first network is a bidirectional ring network, includes first and second interconnect modules, each such module adapted to receive outgoing data traffic on the first network at a data rate not substantially greater than a predetermined maximum rate for one of the ring directions, and to convey the outgoing data traffic to the second network. When a fault occurs in one of the first and second modules, the other module is reconfigured to receive substantially all of the outgoing data traffic and to convey the outgoing data traffic to the second network regardless of whether the outgoing data traffic is transmitted on the first network in the clockwise or in the counterclockwise direction.

Abstract: An apparatus and method for fault detection and isolation in an optical network is disclosed in which each node determines an appropriate response to a line fault or an equipment fault, obviating the need for a central computer to coordinate the actions of each node in response to a fault. Each network node includes a local controller and restoration elements for detecting and responding to faults. Each local controller correllates a first set of optical characteristics measured by optical detectors with the local node with a second set of optical characteristics for the channels reported to the local node from an upstream optical element, such as a neighboring upstream node, to determine if a line switch or equipment switch is required. In a preferred embodiment, each node is communicatively coupled to its neighboring node via an optical supervisory channel, with the neighboring nodes communicating status messages and data on channel characteristics via the optical supervisory channel.

Abstract: If failure is detected in multiple layers, a failure detection recovery processing unit is activated simultaneously in each layer and performs operations up to immediately before switching a main signal. The first layer to reach that stage notifies the other layer of this fact through inter-layer failure recovery information communication terminal and processing units to stop the failure recovery operation of the other layer. The other layer sends back a response to it through the inter-layer failure recovery information communication terminal and processing units, and the layer that first reaches the stage up to immediately before actually switches the main signal based on the result of the response.

Abstract: The present invention is directed to a method of synchronizing data transmission through optical links between first and second communications components. Each of the first and second communications components include an optical laser for transmitting and receiving laser signals to and from each other through the optical links. In an embodiment, the method comprises the steps of: (a) initializing each of the first and second communications components; (b) enabling the optical lasers and optical sensors; (c) exchanging idle packets between the first and second communications components to establish a datapath across the optical links; (d) exchanging test data packets across the datapath established in step (c) to verify connection of the optical links; and (e) upon verification of connection of said optical links in step (d), enabling data flow between said first and second communications components.

Abstract: A protection arrangement for an optical switching system includes protection switching for switch planes in the optical core and for ports in the tributary cards. For a multiple layer switch core protection is also provided between layers. A first layer is for switching optical channels. The protection switches used may be 1×N, 2×N or 3×N MEMS optical switches. The 1×N MEMS provides for protection switching. The 2×N MEMS provides protection switching and testing capability. The 3×N MEMS provides for protection switching, testing and backup of the protection switching. Application of these protection switches is shown in lambda plane switch cores, multiple layer switch cores and combined switch cores.

Abstract: A system for managing signals in an optical network is provided. When a signal is originated by a source node for transmission to a destination node, the source node generates a message. Upon receiving this message, the destination node responds by sending an acknowledgment. Intermediate nodes examine these messages, allowing the nodes to obtain information which is used to take appropriate actions. A node is able to detect a switching event and the output power levels of signals leaving the node are maintained at a predetermined level. When transmission components transmitting a signal are powered up, a sequence of messages is exchanged, allowing the nodes to activate their transmission components in a sequential manner, avoiding signal level interference. Another sequence of messages is exchanged during protection line switching, allowing the nodes to adjust their respective transmission components in a sequential manner so as to avoid a “ringing” effect.

Abstract: The invention relates to an optical telecommunications network comprising several nodes (N1 to N4) connected to one another by optical transmission paths that form several working rings (R1 to R4), each of which passes via each node. Information is transmitted in the network at several different wavelengths. To ensure that the network can be implemented as cost-effectively as possible, it comprises a group of nodes (N1 to N4) including N nodes, a group of working rings (R1 to R4) including N rings, and a group of wavelengths (?1 to ?4) including N wavelengths in such a way that each node in the group of nodes is configured to transmit signals at one wavelength in the group of wavelengths to all rings in the group of rings except to the ring from which it receives signals, and to receive signals at all wavelengths in the group of wavelengths except for its own transmitting wavelength from both directions in only one of the rings in the group of rings.

Abstract: Fault tolerance is provided in a cross-connect system having only duplicated switch fabrics, instead of the triplicated switch fabrics of the prior art. In addition to the two information switch fabrics, the cross-connect system has a relatively small code switch fabric which switches check-code signals generated at each input interface for each input signal sent to an information switch fabric. Fault-detection and error-recovery components in each output interface (1) generate local check-code signals for each outgoing signals received from an information switch fabric and (2) compare those local check-code signals to the corresponding check-code signal received from the code switch fabric to detect a failure and to select a healthy signal as the output signal for that output interface. In one embodiment, input and output interfaces are clustered, and the corresponding input and output check-code signals are multiplexed, for even greater savings in overhead (e.g.

Abstract: A method for protection of ST-M-n/OC-n clear channel connections calls for a protection diagram allowing protection of STM-n/OC-n clear channel signals transmitted from a source point to a destination point. This protection allows overcoming a fall along the path between source point and destination point. It can be used in different types of network structure, for example “ring” or “mesh”. The method calls for duplication of STM-n/OC-n signals at the transmitting end of the subnetwork and transmission over two different routes which can be defined as work and protection paths. To ensure success of the protection diagram the work and protection channels follow different routes. At the receiving end, the signal is selected from the work path or the protection path depending on the quality of the received signals, the protection state and the external commands.

Abstract: An optical network has a main fiber (14) and a protection fiber (16) between a source node (12a) and a destination node (12b). The source node (12a) is provided with a plurality of transponders (22) and a splitter (20) for providing source node data onto the main and protection paths, with the transponders (22) being positioned on the node side of the splitter (20). The destination node (12b) is provided with a plurality of transponders (34) and a switch (36) for selecting which of the main and protection paths to route to a receiver (38) of the node, the transponders (34) being positioned on the node side of the switch (36). This arrangement reduces the number of transponders required, as they are provided before the splitter at the transmitting node, and after the switch at the receiving node. The destination node (12b) preferably further comprises a monitoring arrangement for monitoring the signal from the protection path (16).

Abstract: A data network routing apparatus and method are presented. The data switch comprises a packet engine integrated with an optical engine. The optical engine and packet engine are under common software and/or hardware control, and communicably interconnected. As a result, the physical state of the optics is continually and immediately available to the packet engine, in substantially real time. The packet engine implements a routing algorithm which operates on at least the data traffic in the network and the optical transport topology. The routing apparatus periodically updates the routing algorithm's operands under normal operation, and in the event of the failure of a communications link in the network, the routing apparatus immediately updates the routing algorithm operands in response. A network comprising a plurality of nodes with such immediate rerouting capability is achieved by utilizing a plurality of the disclosed data switches as its nodes.

Abstract: A data bus arrangement for a plurality of nodes connected to each other including a logical decision gate having a plurality of inputs corresponding to the number of nodes. A converter module is connected between each node and the logical decision gate. Each convertor module converts an optical output from one of the nodes to an electrical signal which is fed to one of the inputs of the logical decision gate. A separate switch is connected between an output of the logical decision gate and an input of each one of said convertor modules for controlling the convertor module independent of an output signal on the output of the decision gate.

Abstract: Techniques for reestablishing network address associations upon recovery of a passive optical network (PON) disablement relay on storage address association information. A network node stores address association information in non-volatile memory upon detecting a network disablement. Upon recovery of the PON from the disablement, the network node associates network addresses to clients in accordance with the address association information. The network node may further verify the associations by sending ARP queries for the network addresses to the associated clients. Alternatively, the network nodes may reestablish the address associations by tracking the length of time of the network disablement, and updating address association information in accordance with the length of the disablement.

Abstract: A fully “time tunable” all-optical switch routes/switches digital bits (packets) in an all-optical format for transmission, or for further processing, in an all-optical communication network. The all-optical switch is implemented in either a semiconductor hybrid or in a completely monolithic form. Variable time delay elements adjust the time delay of a clocking signal input and a data packet input. The clocking signal determines the state of two nonlinear optical elements, such as semiconductor optical amplifiers, incorporated in the upper and lower arms of a Mach-Zehnder configuration. An optical coupler is connected to the output of the all-optical switch. The output of data from selected ports of the optical coupler is controlled using the variable time delay elements.

Abstract: Optical systems of the present invention are configured in optical networks including a plurality of optical switch nodes interconnected by a plurality of optical transmission fibers, or other waveguides. The transmission fibers in the network can provide working and/or protection capacity for information, or communications traffic, being transmitted through the network. In various embodiments of the network, multiple diverse, working routes are provided on a single fiber path interconnecting a plurality of switch nodes. The multiple, diverse working routes can then be protected using a common protection fiber or path to provide shared protection. The switch nodes include optical switch configured to provide various levels of optical switching depending upon the network configuration. For example, line switches as well as optical cross-connects and routers can be deployed in the present invention to switch one or more wavelengths between the working and protection fibers.