A 240 Gb/s PAM4 Silicon Micro-Ring Optical Modulator

We report a micro-ring modulator with 0.53 V·cm phase efficiency, 54 GHz bandwidth, and 16.3 nm FSR. We have achieved 224 and 240 Gb/s PAM4 eye diagrams with 1.6 dB and 3.9 dB TDECQ, respectively.