Reduced driving voltage optical duobinary transmitter and its impact on transmission performance over standard single-mode fiber

We have investigated the impact of reducing the electrical driving voltage in a 10-Gb/s optical duobinary transmitter from 100% to 25% of the full swing 2 V/sub /spl pi// of the Mach-Zehnder modulator. Reduction in the driving voltage enhances the signal extinction ratio and reduces the complexity of the transmitter while maintaining the high tolerance of this modulation technique to chromatic dispersion. Transmission at 10 Gb/s with 25% of the full swing over a 182-km unrepeatered span of uncompensated standard single-mode fiber has been achieved with low sensitivity penalty.