Chirp and Dispersion Tolerance of a Single-Drive Push–Pull Silicon Modulator at 28 Gb/s

We experimentally characterized the chirp and dispersion tolerance of a single-drive push-pull silicon Mach-Zehnder modulator. The measured data indicate an effective chirp parameter of -0.8 at V_π drive, which includes contributions from power imbalance, modulation efficiency asymmetry, and inherent free-carrier absorptions. A dispersion tolerance window of 240 ps/nm is demonstrated, with a 1-dB penalty after 10-km fiber dispersion cumulation at 28 Gb/s and BER of 1E-3.