Lucent Technologies Inc.

Timothy Owen Murphy

Gaylord W Richards

David S Levy

Christopher Richard Doerr

Carl Jeremy Nuzman

Krishnan Kumaran

Daniel Yousef Al-Salameh

Edmond J Murphy

Philip J Anthony

Fred Ludwig Heismann

Nachi K Nithi

Alice Elizabeth White

Donald L Husa

An integrated reconfigurable planar lightwave add-drop (RPLAD) multiplexer for use in a WDM optical communication system is arranged such that each drop port can receive any wavelength channel and each add port can transmit on any wavelength channel. Drop port reconfigurability is achieved by integrating a cross-connect functionality into the RPLAD, illustratively using optical 1&#xd7;2 switches to perform 'space' switching. The switches are controlled from a remotely located node controller. Add port reconfigurability is achieved by having tunable lasers and a wavelength independent optical power combiner, which may be a star coupler that is integrated with the other above-mentioned elements. The RPLAD has a modular architecture, so that when RPLAD's are connected by dual unidirectional transmission rings for the purpose of redundancy and failure protection, an RPLAD that fails can be removed and the remaining module can be reconfigured so as to re-route incoming traffic backwards around the still operating optical communication ring.

Integrated reconfigurable optical add/drop multiplexer

Techniques and systems for design of optical switch arrays so as to minimize power requirements are described. A design system includes a computer system hosting a design program. The design program receives parameters for the switch array, including a number N of outputs required, and either a maximum number L of stages allowed or maximum and average power requirements allowed. If power requirements are used as parameters, the design program uses N and the power requirements to compute the value of L. The design program then constructs a minimum power sequence of L switches or N switches, whichever is less. If N is less than L+1, N outputs are present and the array is complete. If N is greater than L+1, the design program then adds switches one at a time to the minimum power switch path of the array, until the array provides N outputs.

Methods and apparatus for constructing switch arrays for routing of optical signals so as to minimize power dissipation

An optical transmission system formed from a plurality of nodes interconnected in a ring configuration via at least two transmission media provides protection capacity for each optical channel. If a channel signal does not meet predetermined criteria, then a loss of signal indication is declared for the channel and one of a plurality of protection switching states is invoked to re-route service traffic carried by the impaired channel to its destination via corresponding protection capacity. The switching states include particular transmission states and at least &ldquo;keep-alive&rdquo; and &ldquo;protection access&rdquo; states.

Shared optical protection ring architecture

An apparatus and method for reducing the number of control elements for crosstalk reduction devices in an optical switching network is disclosed. Crosstalk reduction devices are partitioned into two mutually exclusive groups based on a binary address of the crosstalk reduction device. By successively changing the bits within the destination address of the active signal path within the network, two mutually exclusive groups of crosstalk reduction devices is generated and one control signal is sufficient to operate the devices. The apparatus of the invention comprises a switching module having input channels and output channels, the switching network arranged in a tree topology comprising a first plurality of switching elements adapted to fan-out, said first plurality of switching elements coupled to said input channels; a plurality of crosstalk reduction devices coupled to said first plurality of switching elements, said crosstalk reduction device operable in a passing state and a blocking state; a second plurality of switching elements adapted to fan-in to said output channels, said second plurality of switching elements coupled to said crosstalk reduction devices; and a control signal coupled to each of said plurality of crosstalk reduction devices, said control signal adapted to selectively enable the passing state and the blocking state of said crosstalk reduction device.

Apparatus and method for reducing the number of control elements for crosstalk reduction devices in an optical switching network

The invention disclosed is a circuit for regulating optical power levels. Electrooptic attenuators are used to control optical output intensity by means of feedback loops from the outputs of the attenuators to the electrodes of the attenuators which determine the amount of light going to the outputs. The attenuators may be used in combination with an optical switch array in a wavelength division multiplexing system.

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Fairport, NY, United States of America

Timothy Owen Murphy