Investigation of Four-Wavelength Regenerator Using Polarization- and Direction-Multiplexing

We demonstrate a four-channel extension to the Mamyshev regenerator and investigate its potential for the simultaneous processing of 4 times 10 Gb/s return-to-zero wavelength division-multiplexed channels. Mitigation of the interchannel nonlinearities is achieved through the rapid walkoff induced by both the large differential group delay of a specially developed polarization maintaining highly nonlinear fiber and a bidirectional architecture. Numerical and experimental results demonstrate the reduction of interchannel crosstalk as well as the potential of the scheme for 2R regeneration.