| 摘要 |
A system and method for reducing Raman cross-talk between optical signals having different wavelengths in an optical communications system. Optical signals having wavelengths lambd1, lambd2, lambd3, and lambd4, respectively, are launched into an optical fiber at the headend of the system by an optical transmitter. Each wavelength lambd is preferably separated from each adjacent wavelength by the same amount, DELTAlambd. lambd1 and lambd2 have vertical polarizations and lambd3 and lambd4 have horizontal polarizations. Because there is no Raman cross-talk between orthogonally polarized optical signals, there will be no Raman cross-talk between lambd1 and lambd3, between lambd2 and lambd4, between lambd1 and lambd4, or between lambd2 and lambd3. However, there is Raman cross-talk between lambd1 and lambd2 because each is vertically polarized and also between lambd3 and lambd4 because each is horizontally polarized. The amount of Raman cross talk is minimized because the wavelength difference between vertically polarized signals lambd1 and lambd2, and also between horizontally polarized signals lambd3 and lambd4, is only DELTAlambd, which is the smallest wavelength difference between adjacent optical signals.
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