US Patent:
20100142956, Jun 10, 2010
Inventors:
Julia Y. Larikova - Naperville IL, US
Richard C. Younce - Yorkville IL, US
Mary E. Mizialko - Naperville IL, US
Robert D. Gatze - Aurora IL, US
Assignee:
Tellabs Operation, Inc. - Naperville IL
International Classification:
H04J 14/02
Abstract:
Higher rate channels (e.g., 40 Giga bits or greater) have large bandwidths and are susceptible to inter-channel crosstalk. Optical tunable filters may be used to overcome crosstalk. Tunable filters do not maintain their central wavelength over a long duration or a wide temperature range. An example embodiment of the present invention relates to shaping a channel signal within a dense wavelength division multiplexing signal and may employ a tunable filter and input and output optical power detectors to measure a modulated source channel signal at an input of the tunable filter and a filtered modulated source channel signal at an output of the tunable filter. A controller is configured to adjust a center wavelength of the tunable filter as a function of a difference between measurements of optical power by the optical power detectors. Adjusting the center wavelength shapes the channel signal and overcomes undesired effects for higher rate channels.