Suppression of Rayleigh backscattering in a bidirectional WDM optical link using clipped direct modulation

A novel technique is presented to reduce the Rayleigh-backscattering-induced noise in a bidirectional optical link where the same wavelength is used. The interferometric noise in bidirectional optical links can be reduced by control of the coherence time of the optical source. A clipping modulation of the laser diode provides effective noise spreading. Verification of the proposed technique has been performed through a transmission experiment.