Lucent Technologies Inc.

Mahan Movassaghi

Daniel A Fishman

Robert D Feldman

William A Thompson

David A Sadler

Xiang Liu

Stefan Hunsche

Chunhui Xu

A repeater node for an optical transmission system provides amplification of optical signals and uses a modulated pump signal to transfer status information about the repeater node to a control system via an optical supervisory signal. The pump signal supplied by a pump source to an optical amplifier is modulated with one or more tones that are indicative of status in the repeater node. In a transmission fiber coupled to the output of the optical amplifier, the modulation of the pump signal is transferred to the supervisory signal of the optical transmission system as a result of Raman effect. More specifically, the pump wavelength and the supervisory signal wavelength are such that the modulated tone on the shorter wavelength pump signal is transferred to the longer wavelength supervisory signal. The tone can then be extracted from the supervisory signal and processed at another node in the system.

Method and apparatus for communicating status in a lightwave communication system employing optical amplifiers

A method and apparatus for controlling transients in an optical signal propagating along an optical fiber path interconnecting a plurality of network elements employs a power threshold to determine an appropriate response given a change in optical signal power.

Method and apparatus for controlling power transients in an optical communication system

A method, apparatus and system for reducing gain ripple in a Raman-amplified WDM system includes determining a gain profile of an optical signal transported via a first Raman amplification span in a Raman-amplified WDM system, comparing the determined gain profile to a gain profile of an optical signal transported via a second Raman amplification span, determining, from the comparison, an amount of wavelength adjustment required for a plurality of Raman pumps comprising at least one Raman pump block of the second Raman amplification span to alter the gain profile of an optical signal transported via the second Raman amplification span, such that a cumulative gain profile of an optical signal transported via the first and the second Raman amplification spans approaches a desired gain profile, and generating a control signal suitable for adjusting the wavelengths of the plurality of Raman pumps of the at least one Raman pump block an amount consistent with the determined amount.

Method, apparatus and system for reducing gain ripple in a raman-amplified WDM system

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Middletown, NJ, United States of America

Mahan Movassaghi