Ultra-Low-Power (1.59 mW/Gbps), 56-Gbps PAM4 Operation of Si Photonic Transmitter Integrating Segmented PIN Mach-Zehnder Modulator and 28-nm CMOS Driver

A highly-power-efficient PAM4 silicon photonic transmitter was developed by integrating segmented PIN Mach-Zehnder modulator and CMOS inverter driver. A passive RC equalizing technique successfully enabled clear eye-opening of PAM4 signal up to 56Gbps together with a record-high-efficiency of 1.59 mW/Gbps.