Long-Distance Demonstration and Modeling of Low-Power Silicon Microdisk Modulators

Silicon micro-resonators have been proposed for short-distance intracomputer interconnects and recently for long-distance communications. In this letter, the spectral profile, chirp, and power penalties are theoretically analyzed, measured, and compared for a recent silicon microdisk resonator technology. Theory predicts negative pulse chirping of the transmitted wave which when combined with the dispersion properties of SMF-28 fiber results in no power penalty at 40 km and less than 1 dB for 70 km at 5 Gb/s. The measurement at 5 Gb/s agrees with the theoretically predicted values. Measurement of the modulator at a bandwidth limited speed of 10 Gb/s results in 2- and 6.5-dB power penalties at 40 and 70 km, respectively. Comparison with commercial Mach-Zehnder modulator (MZM) technology at 70 km shows that the silicon microdisk is within 0.5-dB power penalty of the MZM at 5 Gb/s and within 4 dB of the MZM power penalty at 10 Gb/s. Theory and experimental results show silicon photonic modulators can be competitive options for long-distance communications.