A 100 Gb/s PAM4 Two-Segment Silicon Microring Resonator Modulator

We demonstrate a two-segment silicon microring resonator modulator with 100 Gb/s PAM4 modulation. The microring modulator exhibits a FSR of ~ 5.7 nm, a Q factor of ~ 3600, a DC extinction ratio of ~ 13 dB, an electro-optical bandwidth of ~ 40 GHz, and a phase shift efficiency
$\boldsymbol{V_{\pi} \cdot L}\ \mathbf{of}\ \boldsymbol{\sim 1 \mathrm{V}}\cdot \text{cm}$
.