A 128 Gb/s PAM4 Silicon Microring Modulator with Integrated Thermo-optic Resonance Tuning

We report the first demonstration of a silicon photonic microring modulator with modulation data rate up to 128 Gb/s (64 Gbaud PAM4). The microring modulator exhibits an electro-optic phase efficiency of Vπ · L = 0.52 V·cm, an electro-optic bandwidth of 50 GHz, and a measured transmitter dispersion eye closure quaternary of 3.0 dB at this data rate. In addition, the resonant wavelength of the micr...