Electrically band-limited CSRZ signal with simple generation and large dispersion tolerance for 40-Gb/s WDM transmission systems

We present a novel configuration for carrier-suppressed return-to-zero (CSRZ) signal generation, which only requires a single-stage Mach-Zehnder modulator in conjunction with an electrical mixer. An electrical band-limiting filter is also introduced to further reduce the spectral width of the generated CSRZ signal. The proposed scheme is potentially cost-effective, and simulation results show that the electrically band-limited CSRZ signal exhibits larger dispersion tolerance than a conventional CSRZ signal without any degradation in its nonlinearity tolerance.