Abstract: An optical interference modulator comprises a main input, a main output, an optical splitter connected to the main input, first and second MMI couplers, each with a first primary-end access port connected to the splitter; a second primary-end access port connected to the main output; a first secondary-end access port connected to a respective primary waveguide; and a second secondary-end access port connected to a respective secondary waveguide. A light reflector is arranged to reflect light incident from said primary and secondary waveguides back into the same respective waveguide such that light travelling through the respective waveguide from the respective secondary-end access port, after reflection, travels back to the same secondary-end access port. For the MMI couplers, at least one of the respective primary and secondary waveguides comprises a respective light phase modulating device arranged to modulate the phase of light travelling along the corresponding waveguide in either direction.

Abstract: An optical interference modulator comprises a main input, a main output, an optical splitter connected to the main input, first and second MMI couplers, each with a first primary-end access port connected to the splitter; a second primary-end access port connected to the main output; a first secondary-end access port connected to a respective primary wave-guide; and a second secondary-end access port connected to a respective secondary wave-guide. A light reflector is arranged to reflect light incident from said primary and secondary waveguides back into the same respective waveguide such that light travelling through the respective waveguide from the respective secondary-end access port, after reflection, travels back to the same secondary-end access port. For the MMI couplers, at least one of the respective primary and secondary waveguides comprises a respective light phase modulating device arranged to modulate the phase of light travelling along the corresponding waveguide in either direction.

Abstract: Various embodiments relate to a method, device, and machine-readable storage medium including: an optical modem, the optical modem being configured to negotiate a format of an optical communication session with a remote optical transceiver via an optical fiber link; and wherein the optical modem is configured to select a transmission optical wavelength channel for transmitting data of the optical communication session in response to sensing the optical fiber link for light emission and determining that the transmission optical wavelength channel is unused based on the sensing.

Abstract: A manner of providing redundancy protection for a data center network that is both reliable and low-cost. In a data center network where the data traffic between numerous access nodes and a network core layer via primary aggregation nodes, an optical network device such as and OLT (optical line terminal) is provided as a backup aggregation node for one or more of the primary aggregation nodes. When a communication path through a primary aggregation node fails, traffic is routed through the optical network device. In a preferred embodiment, a communication link is formed from a plurality of access nodes to a single port of the OLT or other optical network device via an optical splitter that combines upstream transmissions and distributes downstream transmissions. The upstream transmissions from the plurality of access nodes may occur according to an allocation schedule generated when the backup aggregation node is needed.

Abstract: A manner of providing redundancy protection for a data center network that is both reliable and low-cost. In a data center network where the data traffic between numerous access nodes and a network core layer via primary aggregation nodes, an optical network device such as and OLT (optical line terminal) is provided as a backup aggregation node for one or more of the primary aggregation nodes. When a communication path through a primary aggregation node fails, traffic is routed through the optical network device. In a preferred embodiment, a communication link is formed from a plurality of access nodes to a single port of the OLT or other optical network device via an optical splitter that combines upstream transmissions and distributes downstream transmissions. The upstream transmissions from the plurality of access nodes may occur according to an allocation schedule generated when the backup aggregation node is needed.

Abstract: Embodiments for optical communication are provided in which tunable receiver selects and demodulates a first channel of a WDM signal. An example receiver includes a tunable local oscillator for generating a local oscillator signal approximately centered at a first channel wavelength. An optical hybrid of the receiver receives at a first input a wavelength-division-multiplexed (WDM) signal with a M-ary modulation scheme, wherein M is an integer greater than 2, and at a second input the local oscillator signal. A plurality of detectors detect in-phase and quadrature components of the first channel wavelength output of the optical hybrid, which are digitizing by a plurality of analog-to-digital converters. A digital signal processor processes the digitized in-phase and quadrature components in order to recover data carried by the first channel of the WDM signal.

Abstract: A manner of providing redundancy protection for a data center network that is both reliable and low-cost. In a data center network where the data traffic between numerous access nodes and a network core layer via primary aggregation nodes, an optical network device such as and OLT (optical line terminal) is provided as a backup aggregation node for one or more of the primary aggregation nodes. When a communication path through a primary aggregation node fails, traffic is routed through the optical network device. In a preferred embodiment, a communication link is formed from a plurality of access nodes to a single port of the OLT or other optical network device via an optical splitter that combines upstream transmissions and distributes downstream transmissions. The upstream transmissions from the plurality of access nodes may occur according to an allocation schedule generated when the backup aggregation node is needed.

Abstract: Embodiments for optical communication are provided in which tunable receiver selects and demodulates a first channel of a WDM signal. An example receiver includes a tunable local oscillator for generating a local oscillator signal approximately centered at a first channel wavelength. An optical hybrid of the receiver receives at a first input a wavelength-division-multiplexed (WDM) signal with a M-ary modulation scheme, wherein M is an integer greater than 2, and at a second input the local oscillator signal. A plurality of detectors detect in-phase and quadrature components of the first channel wavelength output of the optical hybrid, which are digitizing by a plurality of analog-to-digital converters. A digital signal processor processes the digitized in-phase and quadrature components in order to recover data carried by the first channel of the WDM signal.

Abstract: A load-balanced network architecture is disclosed in which a traffic flow at a given network node is split into a plurality of parts, and the parts are distributed to respective ones of the plurality of nodes that are designated as participating in a load balancing process for the traffic flow. Each of at least a subset of the participating nodes receiving one of the parts routes at least a portion of its received part to one or more destination nodes.

Abstract: An optical WDM-TDM network includes a plurality of devices, each of the devices including at least one optical add/drop device adapted to drop optical signals of at least one channel of a plurality of received channels and pass through the remaining channels, at least one receiver, for receiving the at least one dropped channel from the at least one optical add/drop device, an aggregation device for assembling optical signals from the at least one receiver into original data formats, at least one transmitter for transmitting wavelength division multiplexed optical signals on the plurality of channels, a de-aggregation device for disassembling input data into blocks of data to be transmitted as optical signals by the at least one transmitter, and a controller for processing a global timing schedule.

Abstract: In a system and method of optical communication, optical signals are generated in multiple wavelength channels. Each optical signal is passively transported from an origination node of a network to a destination node. The destination node is determined by the signal wavelength. For at least some signals, the passive transport includes transport through a branch point of the network, such that the signal wavelength determines the output branch through which the signal is routed. In certain embodiments, signals are generated according to a schedule devised to substantially prevent the concurrent arrival, at the same destination node, of signals having the same wavelength but coming from different origination nodes.

Abstract: An optical router is disclosed having at least one frequency router. The frequency router includes a plurality of input ports and a plurality of output ports. At least one input port simultaneously receives at least two optical signals to be frequency routed, while at least one output port simultaneously presents at least two frequency routed optical signals. Each optical signal to be frequency routed is colored in response to destination information.

Abstract: A load-balanced network architecture is disclosed in which a traffic flow at a given network node is split into a plurality of parts, and the parts are distributed to respective ones of the plurality of nodes that are designated as participating in a load balancing process for the traffic flow. Each of at least a subset of the participating nodes receiving one of the parts routes at least a portion of its received part to one or more destination nodes.

Abstract: In a system and method of optical communication, optical signals are generated in multiple wavelength channels. Each optical signal is passively transported from an origination node of a network to a destination node. The destination node is determined by the signal wavelength. For at least some signals, the passive transport includes transport through a branch point of the network, such that the signal wavelength determines the output branch through which the signal is routed. In certain embodiments, signals are generated according to a schedule devised to substantially prevent the concurrent arrival, at the same destination node, of signals having the same wavelength but coming from different origination nodes.

Abstract: An optical WDM-TDM network includes a plurality of devices, each of the devices including at least one optical add/drop device adapted to drop optical signals of at least one channel of a plurality of received channels and pass through the remaining channels, at least one receiver, for receiving the at least one dropped channel from the at least one optical add/drop device, an aggregation device for assembling optical signals from the at least one receiver into original data formats, at least one transmitter for transmitting wavelength division multiplexed optical signals on the plurality of channels, a de-aggregation device for disassembling input data into blocks of data to be transmitted as optical signals by the at least one transmitter, and a controller for processing a global timing schedule.

Abstract: Apparatus for processing optical signals includes an optical multiplexer integrally formed with at least one optical amplifier. The integral formation of the optical multiplexer and the optical amplifier is performed, for example, by monolithic integration on InP. The optical amplifer is connected to an input port of the optical multiplexer to form an amplifying optical multiplexer. Conversely, the optical amplifier can be connected to an output port of the optical multiplexer to form an amplifying optical demultiplexer. The optical amplifiers have specific gain characteristics based upon known lossy characteristics of an optical signal passing through these devices and specific individual control of each optical amplifier.

Abstract: An optical router and accompanying method utilizing an N×N frequency router and N tunable transmitters. Packets to be routed are “colored” according to their intended destination and applied to an input port of the frequency router such that they appear at a desired output port.

Abstract: A wavelength division multiplex (WDM) cross-connect architecture that can selectively cross-connect, at a wavelength granularity, wavelength channels from any of a plurality of input WDM optical facilities (e.g., fibers) to any of a plurality of output WDM optical facilities. The architecture is based on multi-wavelength modules, which are capable of routing simultaneously N wavelengths. The number of required modules scales only with k2 or less (i.e., k2 modules with N complexity), where k is the number of input/output fibers. The significant reduction in complexity is traded for a decrease in blocking performance; one of the disclosed architectures is strictly non-blocking in the space domain and rearrangeably non-blocking in the wavelength domain, whereas two others are rearrangeably non-blocking in both the wavelength and space domain.

Abstract: A multifrequency laser that uses a waveguide grating router as the filter for frequency control and encloses it within a structure that forms at each selected frequency two paths of slightly different lengths to create a DiDomenico-type of laser that uses a pair of coupled cavities for frequency control. In one embodiment two sets, each of N optical amplifications, are used to create two resonant paths at each frequency. In other embodiments, a portion of the output power is made to travel a second path to provide the second optical path.

Abstract: Temperature compensation of a wavelength-division-multiplexed (WDM) passive optical network (PON) communication system uses power measurements from each of it remote nodes (RNs) to adjust the frequency of an associated multifrequency laser (MFL). Changes in the power level at each RN caused by frequency drift of its waveguide grating router (WGR), due to changes in the WGR temperature, is determined by monitoring the power level received at each RN and corrected by appropriate changes in the temperature of the associated MFL. The WGR uses one output port (e.g., channel 1) which is looped-back through the WGR a second time to increase the temperature sensitivity of the power measurements. A temperature-control algorithm controls the temperature of the MFL as a function of changes in the received power at the WGR.