Title :
Reduction of coherent crosstalk in WDM add/drop multiplexing nodes by bit pattern misalignment
Author :
Khosravani, R. ; Hayee, M.I. ; Hoanca, B. ; Willner, A.E.
Author_Institution :
Dept. of Electr. Eng. Syst., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
Coherent crosstalk in wavelength-division-multiplexed (WDM) add/drop multiplexers and switches places severe limitations on the acceptable crosstalk suppression level. We propose and analyze a method of reducing the effects of coherent crosstalk in add-drop multiplexers by purposely introducing fiber delays on the order of bit times between different crosstalk paths. These delays decorrelate the bit pattern of the main signal with the interfering signals and place some of the crosstalk power in the "0" bits of the main signal instead of the "1" bits. For a 16-channel WDM system, this method reduces the device requirement for crosstalk suppression by /spl sim/10 dB for return-to-zero and /spl sim/5 dB for nonreturn-to-zero transmission.
Keywords :
light coherence; optical crosstalk; optical fibre communication; photonic switching systems; wavelength division multiplexing; 16-channel WDM system; WDM add/drop multiplexing nodes; acceptable crosstalk suppression level; add/drop multiplexers; bit pattern decorrelation; bit pattern misalignment; bit times; coherent crosstalk; crosstalk paths; crosstalk power; crosstalk suppression; device requirement; fiber delays; interfering signals; main signal; nonreturn-to-zero transmission; return-to-zero fibre transmission; severe limitations; wavelength-division-multiplexed; Add-drop multiplexers; Decorrelation; Delay effects; Optical crosstalk; Optical fiber polarization; Optical interferometry; Power engineering and energy; Power generation; WDM networks; Wavelength division multiplexing;
Journal_Title :
Photonics Technology Letters, IEEE
