Bell Communications Research, Inc.

Tellium, Inc.

Charles A Brackett

Krishna Bala

Gee-Kung Chang

Andrew Marc Weiner

Jawad A Salehi

W John Tomlinson

Arturo Cisneros

Jonathan P Heritage

John K Gamelin

Muhammed Z Iqbal

Ghie Hugh Song

A reconfigurable multiwavelength network element includes a first demultiplexer unit for demultiplexing a first multiplexed optical signal from a first optical fiber into a first plurality of optical outputs; a second demultiplexer unit for demultiplexing a second multiplexed optical signal from a second optical fiber into a second plurality of optical outputs; a first multiplexer unit having first optical inputs for receiving signals to be multiplexed together; a second multiplexer unit having second optical inputs for receiving signals to be multiplexed together; and a cross-connect unit having first and second portions, the first portion directing signals received from at least a first one of the first plurality of optical outputs and a first one of the second plurality of optical outputs to a first one of the first optical inputs and a first one of the second optical inputs, the second portion directing signals received from at least a second one of the first plurality of optical outputs and a second one of the second plurality of optical outputs to a second one of the first optical inputs and a second one of the second optical inputs.

Reconfigurable multiwavelength network elements

A horizontally asymmetrically dilated optical switch comprising multiple stages of 2.times.2 optical switching units, especially electro-optic switching units such as acousto-optical tunable filters (AOTFs), which are electrically switchable between a bar state and a cross state to route and switch an optical signal through the switch. The switch is dilated that is, the switching units have an unused input or output so as to dump crosstalk terms into unused outputs. According to the invention, the interconnections between the switching units and their control are such that any optical signal and any crosstalk path passes through equal numbers of bar-state switches and of cross-state switches. Thereby, two advantages are gained. First, no switching path is transparent to a wide bandwidth so that noise cannot recirculate in an amplifying path and go into oscillation. Also, if one state or the other produces greater crosstalk, along no switching path is the larger term accumulated more than the smaller term.

Asymetrically dilated optical cross connect switches

The present invention is directed to a system for the wavelength division multiplexing/asynchronous transfer mode (WDM/ATM) operation of high-capacity optical communication networks. The optical components of the network can transport vast amounts of information, while the ATM-based electronics provides data processing, and information distribution. The capacity of the communications network to reconfigure and rearrange itself is maximized through wavelength translation of its data signals using a limited set of fixed-wavelength channels. The system incorporates an optical fiber communication network ring, or several optical fiber communication network rings that are connected to each other, through which data signals are transmitted and received. Optical WDM cross-connecting switch devices 4a-4e connect adjacent optical fiber rings 3a, 3b to each other, and control the routing of the data signals into and out of the optical fiber rings 3a, 3b. Access node circuits 2a-2d connected to the WDM cross-connecting switch devices 4a-4d can access the data signals in the optical fiber rings 3a, 3b. Each of the access node circuits 2a-2d can then route the data signals to individual user stations 5a-5h connected to it. A network controller 8 configures the WDM cross-connecting switch devices 4a-4e through their corresponding local node controllers 7.

System for wavelength division multiplexing/asynchronous transfer mode

Apparatus and method for large scale asynchronous transfer mode (ATM) switching utilizing tunable lasers and fixed-tuned receivers are provided. The apparatus, an optical switch, includes a plurality of input modules for receiving ATM cells to be switched and a plurality of output modules for outputting the switched ATM cells. The optical switch also includes an optical transmission network for optically transmitting each ATM cell from an input module to a particular output module, and a contention resolution device in electrical communication with the plurality of input modules for selecting the ATM cells from the plurality of input modules to be switched. Preferably, each output module includes a plurality of fixed-tuned receivers and each input module includes a plurality of tunable lasers. The fixed-tuned receivers of each output module are tuned to a particular wavelength so as to pass only those ATM cells optically received from the optical transmission network at the particular wavelength. The tunable lasers are tunable to a plurality of distinct wavelengths for optically transmitting the ATM cell to the optical transmission network at the particular distinct wavelength associated with the output module to which the ATM cell is destined.

Apparatus and method for large scale ATM switching

The present invention is an optical telecommunications system capable of setting up connections between particular pairs of subscriber stations. Illustratively, the Fourier components of radiation pulses produced in a first specific subscriber station are independently phase modulated in accordance with a predetermined code chosen so that the radiation pulse can be detected only in a second specific subscriber station.

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Mendham, NJ, United States of America

Charles A Brackett