Tridirectional transmission systems using polarization control technique

Wavelength-division-multiplexed (WDM) based optical networks are indispensable for current and future high-capacity networking infrastructure. As the growth on the demand of information capacity, tri-directional transmission will be another useful solution for network design, signals interchange and cross connect purpose. Conventional systems use different wavelengths for counter-propagating WDM signals to avoid overlapping the spectra. Though the Rayleigh backscattering (RB) can be reduced, it will restrict the maximum spectral efficiency.