Lucent Technologies Inc.

Other

Albert M Gottlieb

Kulbir Singh Bhalla

David T Neilson

Randy Clinton Giles

John P Hickey

A method and apparatus for training an optical switch include a splitter for splitting an optical signal into a plurality of reduced power optical signals, the plurality of reduced power optical signals being applied to respective input ports of the optical switch, and a plurality of output power measuring devices for measuring the optical power of the optical signals at each of a plurality of output ports of the optical switch. The method and apparatus further include a controller, for adapting operational parameters within respective communications paths of the optical switch in a manner tending to reduce the optical attenuation imparted to switched optical signals within each communications path, the optical attenuation being determined using the input and output power measuring devices.

Apparatus and method for training high density optical cross connects

Signal losses in an optical cross-connect having steerable switching elements for routing optical signals are substantially reduced by controllably and selectively training the steerable switching elements as a function of measured input and output power of a cross-connected optical signal. More specifically, adjustments to the alignment of one or more steerable switching elements associated with a particular cross-connection are performed in a non-intrusive manner to increase the optical signal power in an optical signal while maintaining an active cross-connection of the optical signal. In one illustrative embodiment, optical monitoring arrangements monitor the optical signal power of optical signals coupled to the cross-connect inputs and outputs. The cross-connect includes a switching fabric comprising a plurality of steerable MEMS mirror elements used as switching elements for controllably and selectively directing the light beams within the cross-connect. By comparing the measured optical signal power with a previously stored value representing the expected optical signal power for that cross-connection, small adjustments can then be made, as appropriate, to optimize the alignment of the mirrors associated with the cross-connection. For example, if the difference between the measured and expected optical signal power exceeds a prescribed threshold, then a dithering process is initiated whereby individual mirrors are &ldquo;walked through&rdquo; alternate tilt positions until the measured optical signal power has been optimized, e.g., increased.

System and method for training an optical cross-connect comprising steerable switching elements

An optical signal processing circuit including one or more modules. Each module performs a particular optical signal processing function such as filtering, switching, multiplexing/demultiplexing, monitoring or amplifying one or more optical signals. The modules can be combined to form a wide variety of optical signal processing circuits and systems.

Optical signal processing modules

An arrangement and a method for monitoring and controlling an optical mechanical switch, which may include one or more microelectromechanical switches. In communication using the arrangement or the method, independently of any customer signal, a modulated optical signal is generated at wavelengths, both modulation and optical, that are out-of-band with respect the wavelengths of any transmission signals that may appear. The modulated optical signal is directed toward the optical mechanical switch, and system control parameters are changed to maximize a detected signal after passage through the optical mechanical switch. Any remnants of the modulated optical signal may be removed before arriving at any customer-related terminal. Optical cross-connect switching circuits are exemplary circuits in which the invention may be applied. The modulated optical signal is inserted before or during the transmission of any transmission signal. If accomplished before the transmission of any customer signals, the relevant switch control parameter is dithered by a servo system to increase the amplitude of the detected signal. During the transmission of signals to a customer terminal, a less obtrusive change of a switch control parameter is employed. In either case, the detected signal is used in a servo system to reduce system loss. Since the monitoring and control signals are at known levels, the needed dynamic range for the detector is much reduced.

Control arrangement for optical mechanical switches

A microelectromechanical system in which, operationally independent of the movable element and the component for moving it, a microelectromechanical sensor senses the position of the movable element. The microelectromechanical sensor adjoins the movable element, at least in part, and may be a strain gage, or a gage of a capacitive, piezoelectric, piezoresistive, or pressure type, among others. The resulting signal is fed back to control the component for moving the movable element. In an array of movable elements and sensors, the signal of each sensor is specific to one movable element.

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Maplewood, NJ, United States of America

Albert M Gottlieb