Sorrento Networks, Inc.

Case Western Reserve University

Shouhua Huang

Xin Cheng

Bar-Giora Goldberg

Kai-Ming Feng

David Arthur Smith

Xingyu Zou

Jin-Xin Cai

Alan E Wilner

The present invention provides an expandable and cost-effective high capacity optical communication system using wavelength-division-multiplexing, optical direction guide means and bidirectional transmission of data over an optical waveguide. The use of interleaved bidirectional data channels reduces the minimum spacing between data channels, permitting a greater number of channels over a single optical waveguide.

Wavelength-division-multiplexed optical transmission system with expanded bidirectional transmission capacity over a single fiber

A dynamic power equalization module ( ) for an optical network is provided. It includes a module input ( ) for receiving an optical transmission ( ) containing a combination of different channels (C -C ). Each channel (C -C ) has a different characteristic wavelength (&lgr; -&lgr; ) and different varying power. A power equalization device that is polarization insensitive is connected between the module input ( ) and a module output ( ). The power equalization device is driven by RF acoustic signals ( ). A feedback loop ( ) receives at least a portion of output from the module output ( ) and generates, based upon a comparison of relative powers of the different channels (C -C ), the RF acoustic signals ( ) which drive the power equalization device. The power equalization device is driven such that it dynamically controls transmission of the different channels (C -C ) to substantially equalize power differentials therebetween. The power equalization device includes a parallel array of acousto-optic modulators (AO -AO ).

Dynamic power equalization of many wavelength-division-multiplexed channels in a fiber-optic system

A Clock timing and Data Recovery (CDR) circuit for reconstructing a clock signal from a high speed data signal that contains no clock signal, such as data in a Non-Return-to-Zero format, and is particularly suitable for high data rate optical communication systems. The circuit uses a reference clock with a frequency that is sufficiently close to the data rate, to keep the circuit tuned to the correct frequency even when input data is absent. When input data is present, a quadrature downconverter mixes the reference clock with a series of pulses corresponding to the transition points of the data signal to produce two intermediate signals. These intermediate signals each go through baseband or intermediate band filters, whose outputs are then quadrature modulated to produce the correct output clock signal. Since the filters operate in a much lower frequency range than the associated data rate, the filters can be comparatively simple and economical, and exhibit superior resistance to aging and environmental effects. A wide range of data rates can be accommodated just by changing the frequency of the reference clock, without having to change the filter parameters. For networks that permit a variety of data rates to be used, automatic data rate detection can allow the correct reference clock frequency to be determined and selected for each incoming data message.

Flexible clock and data recovery module for a DWDM optical communication system with multiple clock rates

The present invention provides an expansion subsystem for dense wavelength division multiplexing systems allowing for the time division multiplexed transmission of lower speed information-bearing signals without regard to data rate or transmission format. The subsystem includes a transmitting station having data buffers, encoders for encoding a unique identification code from a channel identification generator, data scramblers, a multiplexing clock and a time division multiplexing unit, and a receiving station generally the mirror image of the transmitting station.

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Huntington Beach, CA, United States of America

Shouhua Huang