44-Gb/s Silicon Microring Modulators Based on Zigzag PN Junctions

We experimentally demonstrate silicon microring modulators with >;40-Gb/s modulation speed based on the carrier-depletion mechanism in reverse-biased PN junctions. A novel zigzag PN junction providing a modulation efficiency of 3.85× 10
^-5
/V and a resistance-capacitance bandwidth of 51 GHz is proposed and demonstrated. The moderate Q factor of ~ 8000 and the operation wavelength detuning are optimized to relieve photon-lifetime-induced bandwidth limitation. Finally, with a voltage swing of 3 V, high-speed modulation of 20 and 44 Gb/s is experimentally demonstrated with the extinction ratio of 3.45 and 3.01 dB, showing great potential in the application of ultrahigh-capacity optical interconnects.