05696615 is referenced by 43 patents and cites 6 patents.

The present invention provides an improved wavelength division multiplexed optical communication system which includes optical amplifiers having substantially uniform gain in the spectral region from 1540 to 1560 nm. The WDM optical communication system includes an optical transmission line optically communicating with plural optical signal sources for carrying a wavelength division multiplexed optical communication signal. At least one optical amplifier is positioned in the optical transmission line for amplifying the wavelength division multiplexed optical communication signal. The amplifier has at least two amplifier stages. The first amplifier stage includes a first length of rare-earth doped optical fiber and the second amplifier stage includes a second length of rare-earth doped optical fiber. At least one passive optical component is positioned between the first and second amplifier stages selected from optical isolators, optical filters, optical circulators, Bragg gratings, and wavelength division multiplexers. A first optical pump which outputs a pump signal at a first wavelength optically communicates with the first amplifier stage and a second optical pump which outputs a second pump signal at a second wavelength optically communicates with the second amplifier stage. The first and second lengths of the rare-earth-doped optical fiber and the first and second optical pump signals are selected such that the gain of the first amplifier stage has a first gain slope within the spectral region of the multiplexed optical signal and the second amplifier stage has a second gain slope within the spectral region of the multiplexed optical signal. The first and second gain slopes are configured such that the composite of the first gain slope and the second gain slope produces a substantially constant gain within a spectral region from 1540 to 1560 nm.

Title
Wavelength division multiplexed optical communication systems employing uniform gain optical amplifiers
Application Number
8/554976
Publication Number
5696615
Application Date
November 13, 1995
Publication Date
December 9, 1997
Inventor
Stephen B Alexander
Millersville
MD, US
Agent
Margaret Burke
Assignee
Ciena Corporation
MD, US
IPC
H04J 14/02
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