Lucent Technologies Inc.

Agere Systems Guardian Corp.

Magaly Spector

Gadi Lenz

Nathan Myron Denkin

Torben N Nielsen

William A Thompson

Ranjan Dutta

Diego Fernando Grosz

Stan Lumish

Alain P Kung

Alejandra B Gurevich

A method and apparatus for determining the dispersion characteristics of minimum phase filters using substantially only an amplitude response of a minimum phase filter under test includes fitting an amplitude spectrum of the minimum phase filter with a substantially straight line curve, and determining the dispersion characteristics of the minimum phase filter using the straight line curve and the relationships determined by the inventors. Various inventive equations determined by the inventors representative of the relationship between an amplitude response of a minimum phase filter and the dispersion characteristics of the minimum phase filter are used for determining the dispersion characteristics of the minimum phase filter.

Method for determining the dispersion characteristics of minimum phase filters

A method and system in accordance with the present invention greatly reduces the gain error due to Raman gain tilt for individual channels in an optical communication system during a transient event by determining a shift in average power (and thus wavelength) and using the determined shift to alter the average gain in the optical communication system. In various embodiments of the present invention, the average gain of the optical communication system is altered by altering the average gain of an amplifier in the optical communication system. In alternate embodiments of the present invention having an in-line optical filter, the average gain of the optical communication system may be altered by altering the filtering of the optical channels in the optical communication system.

Method and system for reducing Raman gain tilt error

The invention comprises a method and apparatus for implementing a relatively low cost add/drop multiplexer (OADM) wherein pre-demux and post-mux dispersion compensation is employed in a manner that substantially avoids imparting additional dispersion compensation to pass-through wavelength channels in a WDM system.

Apparatus and method for managing dispersion within an optical add/drop module

An optical wavelength add/drop multiplexer (WADM) is configured to add or drop two or more signals each associated with one of a plurality of channels in a wavelength division multiplexed (WDM) signal. The WADM comprises an optical circulator that is optically coupled at one port to two or more serially interconnected fiber Bragg gratings (FBGs), and is optically coupled at another port to a thin film filter including two or more serially interconnected thin film filter elements. Each of the two or more FBGs is matched with a thin film filter element, both arranged to be responsive to signals associated with one of the plurality of channels. Bandwidth and dispersion properties for the FBGs are selected to permit operation of the WADM at two distinct signal data rates. To equalize associated insertion losses in embodiments of the invention arranged to add or drop two or more signals, the FBGs are matched to the thin film filter elements in inverse order with respect to their optical distance from the optical circulator.

Optical wavelength add/drop multiplexer for dual signal transmission rates

A method and apparatus are disclosed for providing optical channel adding/dropping capability within a WDM filter-bypass device. The device comprises an optical filter, an optical switch, and means for receiving a control signal to configure the optical switch. When configured in a filter state, the switch routes the WDM signal through the filter to drop, add or drop and add one or more pre-selected WDM channels. When configured in a bypass state, the WDM signal bypasses the filter. A series of filter-bypass devices may be interconnected to increase the number of optical channels that can be dropped or added.

Add/drop filter for a multi-wavelength lightwave system

Optical amplifiers are typically disposed along the transmission path of an optical system. If a large number of optical amplifiers, e.g., eight, are so disposed, then it is likely that an appreciable level of so-called power divergence will occur among the optical signals forming a composite optical signal that traverses the path. Disadvantageously, when the composite signal is received at a destination and demultiplexed, a number of the demultiplexed optical signals will contain components of the other demultiplexed optical signals as a result of such power divergence. This problem is readily handled using a facility which greatly suppresses such components in a demultiplexed optical signal.

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Holmdel, NJ, United States of America

Magaly Spector