120 Gbit/s PAM-4 Signaling Using a Silicon-Organic Hybrid (SOH) Mach-Zehnder Modulator

Four-level pulse amplitude modulation (PAM-4) signals are generated using a silicon-organic hybrid (SOH) push-pull Mach-Zehnder modulator. We demonstrate data rates (symbol rates) of 120 Gbit/s (60 GBd) with a 500 micrometer long device fabricated through a commercial silicon photonic foundry.