Abstract: Embodiments of the present invention analyze a plurality of parallel channels and identify specific channel(s) that have skew outside of an acceptable skew error margin. In certain embodiments, this skew is identified by determining the timing misalignment between a channel under test and a deskew channel. Other channels within the plurality of channels are masked by transmitting a repeating masked bit pattern. This timing misalignment may be measured by comparing a segment within the channel under test to a corresponding segment within the deskew channel and identifying a time differential between the two segments.

Abstract: A method is disclosed for monitoring and controlling the bit error rate (BER) in an optical communication network where an optical receiver in the optical transmission network. The method includes the steps of decombining a combined channel signal received from the network and then monitoring a real time bit error rate (BER) of a decombined channel signal. The determined BER is then communicated, such as through an optical service channel (OSC) to an optical transmitter source that is the source of origin of the channel signal. Based upon the determined BER, the chirp of a channel signal modulator at the optical transmitter source that generated the monitored channel signal is adjusted by, for example, adjusting its bias. The same channel signal received at the optical receiver can be monitored again to determine if an acceptable level for the BER has been achieved by the previous chirp adjustment.

Abstract: Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: Embodiments of the present invention route a wavelength division multiplexed signal across multiple communication paths using skew characteristics of at least some of the communication paths. The network is a wavelength division multiplexed optical transport network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.

Abstract: A transmission line is provided with added shunt resistance, RSH, distributed along the length of the micro transmission line permitting the extension of constant characteristic impedance to the transmission line to lower signal frequencies. The loss in gain to the signal propagating the transmission line due to the added resistance can be compensated for by amplification provided at the output of the transmission line or at output taps provided along the length of the transmission line such as in cases where the line is utilized as a circuit delay line. An exemplified application disclosed is an analog delay line formed as a metal microstrip in an IC chip circuit provided, for example, in a feed forward equalizer (FFE).

Abstract: Embodiments of the present invention compensate for skew across a wavelength division multiplexed network. The network is a wavelength division multiplexed optical transport network. The skew compensation can be performed electrically or optically. It can be performed on the transmission side of the network, the receiver side of the network or at any intermediary node on the network.

Abstract: Embodiments of the present invention route a WDM signal across multiple communication paths using skew characteristics of at least some of the communication paths. The network is an optical transport network, using either circuit or packet based switching, and wavelength division multiplexed wavelengths and/or optical carrier groups (“OCGs”) over a fiber link to another node in the network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.

Abstract: Embodiments of the present invention determine skew relative to a plurality of communication paths on a network system. The network is a wavelength division multiplexed optical transport network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.

Abstract: Embodiments of the present invention provide an optical port that can be configured to support either high speed or low speed optical signals. In particular, these embodiments comprise a switch that defines a data-rate dependent path between the front-end optics of a network node and internal processing electronic modules. As a result, either high speed or low speed pluggable adapters may be inserted within a port and supported by the processing electronic modules.

Abstract: An optical transmission network is inherently asynchronous due to the utilization of a variable overhead ratio (V-OHR). The network architecture makes extensive use of OEO regeneration, i.e., deals with any electronic reconditioning to correct for transmission impairments, such as, for example, FEC encoding, decoding and re-encoding, signal reshaping, retiming as well as signal regeneration. The optical transmission network includes a plesiochronous clocking system with intermediate nodes designed to operate asynchronously with a single local frequency clock without complicated network synchronization schemes employing high cost clocking devices such as phase locked loop (PLL) control with crystal oscillators and other expensive system components.

Abstract: An optical transmission network is inherently asynchronous due to the utilization of a variable overhead ratio (V-OHR). The network architecture makes extensive use of OEO regeneration, i.e., deals with any electronic reconditioning to correct for transmission impairments, such as, for example, FEC encoding, decoding and re-encoding, signal reshaping, retiming as well as signal regeneration. The optical transmission network includes a plesiochronous clocking system with intermediate nodes designed to operate asynchronously with a single local frequency clock without complicated network synchronization schemes employing high cost clocking devices such as phase locked loop (PLL) control with crystal oscillators and other expensive system components.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An optical transmission network is inherently asynchronous due to the utilization of a variable overhead ratio (V-OHR). The network architecture makes extensive use of OEO regeneration, i.e., deals with any electronic reconditioning to correct for transmission impairments, such as, for example, FEC encoding, decoding and re-encoding, signal reshaping, retiming as well as signal regeneration. The optical transmission network includes a plesiochronous clocking system with intermediate nodes designed to operate asynchronously with a single local frequency clock without complicated network synchronization schemes employing high cost clocking devices such as phase locked loop (PLL) control with crystal oscillators and other expensive system components.

Abstract: Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.

Abstract: An optical transport network comprises a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip and a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip.

Abstract: A method is disclosed for monitoring and controlling the bit error rate (BER) in an optical communication network where an optical receiver in the optical transmission network. The method includes the steps of decombining a combined channel signal received from the network and then monitoring a real time bit error rate (BER) of a decombined channel signal. The determined BER is then communicated, such as through an optical service channel (OSC) to an optical transmitter source that is the source of origin of the channel signal. Based upon the determined BER, the chirp of a channel signal modulator at the optical transmitter source that generated the monitored channel signal is adjusted by, for example, adjusting its bias. The same channel signal received at the optical receiver can be monitored again to determine if an acceptable level for the BER has been achieved by the previous chirp adjustment.

Abstract: An optical receiver photonic integrated circuit (RxFIC) comprises a semiconductor monolithic chip having an input to receive from an optical transmissior link a combined channel signal originating from an optical transmitter source and comprising a plurality of channel signals having different wavelengths forming a wavelength grid. An optical decorobiner is integrated in the chip and optically coupled to the input to receive the multiplexed channel signal and provide a decombined individual channel signal on an output waveguide of a plurality of such output waveguides provided from the optical decombiner. A plurality of photodetectors are also integrated in the chip and each photodetector is optically coupled to one of the output waveguides to receive a decombined channel signal and convert the channel signal to an electrical signal.

Abstract: The present invention provides a system, apparatus and method for modularly adapting a network node architecture to function in one of a plurality of potential node types. The architecture includes a configurable switching element, integrated optics, and a plurality of modules that allow a “type” of node to be adapted and configured within the base architecture. The module interfaces may be optical or electrical and be used to construct various different types of nodes including regenerators, add/drop nodes, terminal nodes, and multi-way nodes using the same base architecture.

Abstract: The present invention provides a system, apparatus and method for recovering a client signal clock. The present invention is able to more effectively remove jitter within a clock signal by providing a phase shifting element in the feedback of a PLL system to compensate for sudden changes in an input reference clock. The PLL system provides flexible clock recovery so that it can accommodate various payload types because it extracts a client clock signal independent of a corresponding justification count number.