Limitations imposed by Rayleigh backscattering in closely interleaved, bidirectional WDM transmission systems

By deriving signal-backscattering and backscattering-backscattering beat noises, this letter quantifies the performance impairment due to backscattering produced by closely spaced counterpropagating signals. Experiments using 10-Gb/s data signals verify the theoretical analysis. The interference between signal and backscattering induces significant impairment when their channel separation is less than the sum of the data rate and signal spectrum width. The spectral efficiency limitation imposed by backscattering is clarified for closely spaced, interleaved bidirectional transmission systems.