Abstract: In some examples, an optical node includes transition logic to: receive an indication of a data channel to be added across an optical medium, the data channel to occupy a portion of an optical spectrum; in response to a receipt of the indication, divide the data channel into a plurality of sub-channels; and sequentially add each of the plurality of sub-channels across the optical medium in a particular order.

Abstract: A hybrid electronic optical chip has a first photonic element with which a first diode is associated, a second photonic element with which a second diode is associated and a common electrical driver connected to the first and second diodes by a common electrical connection with opposite polarity. The electrical driver generates a common electrical drive signal divided in time into first and second drive signal components for independently driving the first and second photonic elements through the common electrical connection.

Abstract: There is provided methods and apparatuses for transferring photonic cells or frames between a photonic switch and an electronic switch enabling a scalable data center cloud system with photonic functions transparently embedded into an electronic chassis. In various embodiments, photonic interface functions may be transparently embedded into existing switch chips (or switch cards) without changes in the line cards. The embedded photonic interface functions may provide the switch cards with the ability to interface with both existing line cards and photonic switches. In order to embed photonic interface functions without changes on the existing line cards, embodiments use two-tier buffering with a pause signalling or pause messaging scheme for managing the two-tier buffer memories.

Abstract: A method of managing an optical communications network comprising a plurality of nodes interconnected by optical sections. The method comprises: identifying one or more pairs of adjacent DL-equipped nodes at which dummy light (DL) hardware is deployed, respective dummy light (DL) hardware being deployed at fewer than the plurality of the nodes of the optical communications network, the respective DL hardware deployed at a particular node configured to supply dummy light to each optical section extending from the particular node, and defining a respective single-section DL path between each identified pair of adjacent DL-equipped nodes; identifying one or more pairs of non-adjacent DL-equipped nodes at which DL hardware is deployed, and defining a respective multi-section DL path between each identified pair of non-adjacent DL-equipped nodes; and causing the deployed DL hardware to supply DL light to each of the single- and the multi-section DL paths.

Abstract: A hybrid electronic optical chip has a first photonic element with which a first diode is associated, a second photonic element with which a second diode is associated and a common electrical driver connected to the first and second diodes by a common electrical connection with opposite polarity. The electrical driver generates a common electrical drive signal divided in time into first and second drive signal components for independently driving the first and second photonic elements through the common electrical connection.

Abstract: Short-term optical recovery systems and methods in coherent optical receivers minimize recovery time for fault scenarios and signal reacquisition while maintaining robust signal acquisition. The short-term optical recovery systems and methods include special techniques and algorithms to minimize recovery time, making coherent systems similar in time as conventional direct detection recovery. The short-term optical recovery systems and methods include an expedited acquisition engine that includes a reference clock recovery, a compensator to remove chromatic dispersion, a burst framer, and a compensator to remove polarization dispersion. Importantly, the expedited acquisition engine uses a memory oriented architecture to allow some properties of the acquisition engine to be stored during initial acquisition and, hence, later on be deployed in any fault scenario to expedite further recovery of a signal.

Abstract: A hybrid electronic optical chip has a first photonic element with which a first diode is associated, a second photonic element with which a second diode is associated and a common electrical driver connected to the first and second diodes by a common electrical connection with opposite polarity. The electrical driver generates a common electrical drive signal divided in time into first and second drive signal components for independently driving the first and second photonic elements through the common electrical connection.

Abstract: A system and method for a tunable optical delay line. The tunable optical delay line comprises a coarse delay portion that provides a coarse delay amount, the coarse delay portion including a coarse delay selection element in conjunction with a coarse delay element, the coarse delay selection element incorporated on-chip into a photonic integrated circuit (IC) component, the coarse delay element being disposed off-chip of the photonic IC component and interconnected with the coarse delay selection element; and a fine delay element that provides a fine delay amount, the fine delay element interconnected in series with the coarse delay selection element, the optical delay line being tunable to a target delay amount by agglomerating the coarse and fine delay amounts.

Abstract: A system and method for a tunable optical delay line. The tunable optical delay line comprises a coarse delay portion that provides a coarse delay amount, the coarse delay portion including a coarse delay selection element in conjunction with a coarse delay element, the coarse delay selection element incorporated on-chip into a photonic integrated circuit (IC) component, the coarse delay element being disposed off-chip of the photonic IC component and interconnected with the coarse delay selection element; and a fine delay element that provides a fine delay amount, the fine delay element interconnected in series with the coarse delay selection element, the optical delay line being tunable to a target delay amount by agglomerating the coarse and fine delay amounts.

Abstract: A method and apparatus for operating an optical switching fabric or other optical device are provided. The device has multiple input and output ports to be selectably connected together via optical paths. For a requested configuration, an optical device configuration is determined based on a loss metric, which is based on one or both of: a number of crossings of the optical paths; and a length of the optical paths. The crossings can be waveguide crossings within the switching fabric. The configuration can be obtained by selecting particular intermediate stages of the switching fabric for carrying particular optical paths. The number of waveguide crossings, or the variation in the number of waveguide crossings, can be limited or minimized in the selected configuration. In one embodiment, an initial solution is determined, and the intermediate stages of the switch are re-ordered to obtain an improved solution in terms of the loss metric.

Abstract: A method and apparatus for operating an optical switching fabric or other optical device are provided. The device has multiple input and output ports to be selectably connected together via optical paths. For a requested configuration, an optical device configuration is determined based on a loss metric, which is based on one or both of: a number of crossings of the optical paths; and a length of the optical paths. The crossings can be waveguide crossings within the switching fabric. The configuration can be obtained by selecting particular intermediate stages of the switching fabric for carrying particular optical paths. The number of waveguide crossings, or the variation in the number of waveguide crossings, can be limited or minimized in the selected configuration. In one embodiment, an initial solution is determined, and the intermediate stages of the switch are re-ordered to obtain an improved solution in terms of the loss metric.

Abstract: There is provided methods and apparatuses for transferring photonic cells or frames between a photonic switch and an electronic switch enabling a scalable data center cloud system with photonic functions transparently embedded into an electronic chassis. In various embodiments, photonic interface functions may be transparently embedded into existing switch chips (or switch cards) without changes in the line cards. The embedded photonic interface functions may provide the switch cards with the ability to interface with both existing line cards and photonic switches. In order to embed photonic interface functions without changes on the existing line cards, embodiments use two-tier buffering with a pause signalling or pause messaging scheme for managing the two-tier buffer memories.

Abstract: A wavelength selective switch (WSS), reconfigurable optical add-drop multiplexer (ROADM) and methods of determining a condition of a domain network section are provided. The WSS and ROADM include a light source for sending an optical signal having a characteristic. The method comprises instructing a light source to send an optical signal across an optical link, obtaining measurements of characteristic values of the optical signal received at and sent by components along the domain network section, comparing the characteristic values to pre-defined limits, and determining the condition of the domain network section based on the characteristic values.

Abstract: Aspects of the disclosure involve a source node, having some predetermined knowledge of the optical network generating a list of nodes and/or optical links between nodes that form a route in the optical network from the source node to the destination node. The nodes in the optical network do not necessarily need to know the entire route from source node to destination node. Each node simply decodes the control information identifying the next hop in the route towards the destination node. By utilizing the decoded control information identifying the next hop, a switch in the node can be controlled to route the optical signal including the payload and some or all of the control information onto the next optical link toward the destination node.

Abstract: A monitoring and calibration apparatus for an optical networking device such as ROADM is provided. Reflectors are integrated into the device, for example at the ends of optical interconnect cables. The reflectors reflect light in specific monitoring wavelengths and pass other wavelengths such as those used for communication. A light source emits monitoring light which is reflected by the reflector and measured by a detector to measure the integrity of optical paths. The optical paths can include optical cables and cable connectors. Path integrity between different modules of the device can therefore be monitored. Multiple reflectors, reflecting light in different wavelengths, can be placed in series along the same optical path and used to monitor multiple segments of the path. A wavelength selective switch (WSS) of the device can be used to route monitoring light to different optical paths. The WSS also operates to route communication signals in the device.

Abstract: A method for assigning a network path after receiving a connection request to connect a first node with a second node of a network. The method including evaluating a network utilization parameter of the network, such as a network load or blocking probability, at that point in time. If the network utilization parameter is below a minimum threshold level, the method includes carrying out the steps of identifying a set of n network paths through the network that connect the first node with the second node and are absent non-linear links, performing network path selection by selecting p network paths from the set of n network paths that have the best linear OSNR, and, selecting a network path from the set of p network paths that balances the wavelength utilization between the first node and the second node of a network.

Abstract: A method of managing an optical communications network comprising a plurality of nodes interconnected by optical sections. The method comprises: identifying one or more pairs of adjacent DL-equipped nodes at which dummy light (DL) hardware is deployed, respective dummy light (DL) hardware being deployed at fewer than the plurality of the nodes of the optical communications network, the respective DL hardware deployed at a particular node configured to supply dummy light to each optical section extending from the particular node, and defining a respective single-section DL path between each identified pair of adjacent DL-equipped nodes; identifying one or more pairs of non-adjacent DL-equipped nodes at which DL hardware is deployed, and defining a respective multi-section DL path between each identified pair of non-adjacent DL-equipped nodes; and causing the deployed DL hardware to supply DL light to each of the single- and the multi-section DL paths.

Abstract: One aspect of the disclosure is directed to a system and method for determining the propagation delay for a signal to traverse an optical fiber between two transceivers. The method is performed by the first transceiver and includes transmitting a message to the second transceiver over a first optical fiber. The method further includes receiving on the first optical fiber a reply message from the second transceiver including an indication of the internal time for the second transceiver to transmit the reply message. The method further includes determining the time interval from the time the message was transmitted to the time the first transceiver received the reply message. The method further includes calculating the propagation delay from the time interval and the internal time. The method further includes configuring the first transceiver to receive data traffic from the second transceiver on a second optical fiber.

Abstract: A system and method for obfuscating an optical signal is disclosed. Obfuscating the optical signal may make it more difficult for the optical signal to be detected by an interloper. In one embodiment, an optical signal is received at an optical transmitter, and an obfuscated optical signal is generated by performing a modification of the received optical signal. The obfuscated optical signal is then transmitted from the optical transmitter to an optical receiver. An at least partially deobfuscated optical signal is generated at the optical receiver by performing a modification of the obfuscated optical signal. The modification performed at the optical receiver corresponds to the modification performed at the optical transmitter.

Abstract: One aspect of the disclosure is directed to a system and method for determining the propagation delay for a signal to traverse an optical fiber between two transceivers. The method is performed by the first transceiver and includes transmitting a message to the second transceiver over a first optical fiber. The method further includes receiving on the first optical fiber a reply message from the second transceiver including an indication of the internal time for the second transceiver to transmit the reply message. The method further includes determining the time interval from the time the message was transmitted to the time the first transceiver received the reply message. The method further includes calculating the propagation delay from the time interval and the internal time. The method further includes configuring the first transceiver to receive data traffic from the second transceiver on a second optical fiber.