High speed silicon microring modulator employing dynamic intracavity energy balance

High speed coupling-modulation of a microring-based light drop structure is proposed, which removes severe signal distortion due to intracavity energy depletion and separates the modulation speed from the resonator linewidth restriction. Extinction ratio improvement from <1 dB to >20 dB with 40 Gb/s non-return-to-zero (NRZ) signals is obtained with 25 times smaller drive voltage. The tolerance to active ring propagation loss is increased from 5 dB/cm to over 25 dB/cm with less than 5% modulation bandwidth reduction. The possibility of obtaining 160 Gb/s NRZ signal with no more than 4 V drive voltage and less than 5 dB insertion loss is highlighted.