High-Bandwidth Silicon Strip Waveguide-Based Optical Modulator in Series Push-Pull Configuration

Silicon modulators play a crucial role in optical communication systems. Over the past thirty years, there has been a notable enhancement in the bandwidth of silicon modulators; however, their operational speed remains constrained by the resistance-capacitance (RC) time constant. This study presents a silicon strip waveguide-based modulator configured in a series push-pull (SPP) arrangement, which effectively mitigates the limitations imposed by the RC time factor. The modulator exhibits a flat electro-optic (EO) response extending up to 68 GHz. Additionally, it achieves a phase shift of 0.022 radians for a C-band optical wave when subjected to a 15 GHz radio-frequency (RF) modulation signal with an amplitude of 2.45 V.