Ciena Corporation

Nortel Networks Corporation

Lg-ericsson Co., Ltd.

Northern Telecom Limited

Lg-nortel Co., Ltd.

Douglas James Beckett

Brandon C Collings

Bin Cao

Rong Chen

Sanjay Choudhary

Tom M Luk

Maurice M O'Sullivan

Michael Andrew Reimer

Xuefeng Tang

David M Adams

Eddie Fung

Lawrence J Nociolo

Jozef Finak

Bruce A Richardson

Robert A Bruce

Nourhan Eid

Ronqqing Hui

A method of estimating nonlinear transmission impairments of an Optical Channel (OCh) trail in an optical communications network. A per-span nonlinear field variance is calculated for each span of the trail. The per-span nonlinear field variance represents nonlinearly induced noise due to the transmission impairments of that span. The nonlinearly induced noise being imparted to a signal transmitted through the trail and detected by the receiver. A respective covariance between the nonlinear fields contributed by each span pair of the OCh trail is computed. The covariance represents the correlation of the nonlinearly induced noise imparted to the signal within the first span of a span pair with the nonlinearly induced noise imparted to the signal within the second span of the pair. A covariance matrix is populated using the computed per-span variance values and covariance values. A total nonlinear field variance is computed by summing over the covariance matrix elements.

Rapid calculation of nonlinear optical transmission impairments

A Wavelength Division Multiplexed Passive Optical Network (WDM-PON) includes a plurality of broadband light sources, each broadband light source being connected to receive a respective data signal and generating a corresponding modulated broadband optical signal. An Array Waveguide Grating (AWG) is connected for receiving each modulated broadband optical signal through a respective branch port and for generating a filtered broadband signal. The AWG implements a filter function comprising a respective pass-band associated with each branch port such that the filtered broadband signal exhibits a respective intensity peak associated with each pass-band. Each intensity peak is modulated with data from a respective one of the broadband light sources. A bandwidth of the respective modulated broadband optical signal generated by each broadband light source is at least equal to the width of a channel-band of the AWG.

Color free WDM PON based on broadband optical transmitters

A system for generating an optical CATV comb comprising a plurality of wavelength division multiplexed (WDM) optical CATV signals. A set of one or more lasers generate a plurality of narrow-band continuous wave (CW) lights, each CW light having a respective predetermined wavelength and optical power level. An optical MUX couples the plurality of CW lights into a WDM continuous wave light. A broadband optical modulator responsive to a CATV signal modulates the WDM continuous wave light to generate the optical CATV comb.

Bulk modulation of multiple wavelengths for generation of CATV optical comb

A method of estimating an injection power of seed light injected into an injection-seeded transmitter. A back face monitoring (BFM) response of the injection-seeded transmitter is determined, and data representative of the BFM response stored in a memory. During run-time, a controller of the injection-seeded transmitter, detects a temperature of the injection-seeded transmitter and an instantaneous BFM current. BFM response data is obtained from the memory based on the detected temperature, and the seed light injection power estimated based on the obtained data and the detected instantaneous BFM current.

Tracking injection seeding power based on back facet monitoring (BFM) of an injection seeded laser

The present invention provides methods and systems to stabilize an optical network against nodal gain changes through two nested control loops for controlling node gain and node output power. The present invention includes two nested control-loops running at different update speeds including: an inner, faster, control-loop which sets the gains and losses within a node to achieve a node-gain target, and a node-gain target for the inner loop is set by an outer, slower, control loop that whose target is the node output power. Advantageously, the present invention reduces the problem of concatenated overshoot by minimizing the control-loop response to events that occur at other nodes.

Methods and systems to stabilize an optical network against nodal gain changes

The present invention provides systems and methods to convert a reconfigurable optical node multiple-input multiple-output (MIMO) system to a single-input single-output (SISO) system suitable for a proportional-integral-differential (PID) control process. Advantageously, the present invention allows PID control to apply to a MIMO optical node by modeling the node as two SISO systems. The present invention optimizes the division of gain and loss between components in the reconfigurable optical node. This provides means to control the net gain and loss of a series of components when the component chain being controlled includes those components that have a single action affecting multiple channels and components that affect only one channel. The present invention utilizes control of a single quantity of amplifier gain minus attenuation for each channel, and the coupling together of all channels in the amplifier which makes the channels inter-dependent.

Systems and methods for a multiple-input, multiple-output controller in a reconfigurable optical network

The present invention provides a colorless multiplexing system and method for detecting new optical channels at power levels below that which would cause data errors in existing traffic, and on top of background light, thus, overcoming a known risk inherent in colorless multiplexing&#x2014;that a channel of the same wavelength as an existing channel is incorrectly added to the original working, traffic-carrying, channel's path.

System and method for a channel guard in a reconfigurable optical add-drop multiplexer

A method and apparatus for measuring the magnitude of multiple path interference (MPI) in a device under test (&ldquo;DUT&rdquo;) is disclosed. The DUT preferably forms part of an optical test system. The test system includes a light source, two back reflection paths, an output path, a lightwave signal analyzer and a computer. Before measuring MPI, the back reflection paths are calibrated. The input and output conditions are set and spectral data is collected. The spectral data is integrated to give a value for beat-noise power. The beat-noise power measurement allows generation of a crosstalk power ratio. The crosstalk power ratio is indicative of magnitude of multiple path interference.

Method and apparatus to determine a measurement of optical multiple path interference

A method of reducing thermally-induced emission wavelength shift in laser diodes. In addition to the conventional ridge contact for supplying the modulation current to the laser diode a second ridge contact is formed on the device. A compensation current of substantially the same frequency as the modulation current but having an opposite phase is applied to the second contact. This compensation current is selected to substantially neutralize the transient temperature variations due to changes in the modulation signal and result in a generally steady state thermal situation.

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Kanata, Canada

Douglas James Beckett