Silicon-Based Microring Resonator Modulators for Intensity Modulation

We numerically analyze the characteristics of silicon-based microring modulators consisting of a single-ring resonator. Performance of the devices as digital intensity modulators is examined in terms of extinction ratio, pulsewidth, frequency chirp, spectral broadening, and signal quality. Three types of the modulators built in single-waveguide under-/overcoupling and dual-waveguide configurations are discussed. We show that cavity dynamics significantly affect the modulation properties. Data transmission performance over single-mode fibers is also presented. A silicon microring modulator with negative chirp could achieve 0.8 dB power penalty in 80-km fiber transmission without dispersion compensation.