A 40 Gb/s PAM-4 monolithically integrated photonic transmitter in 0.25 µm SiGe:C BiCMOS EPIC platform

摘要

This paper presents the design and characterization of a monolithically integrated optical transmitter fabricated in the 0.25 µm SiGe:C BiCMOS EPIC technology of IHP. The prototype comprises a 15-segment depletion-type Si Mach-Zehnder modulator (MZM) with total length of 5.67 mm and multichannel driver amplifier exhibiting integrated 4-bit digital-to-analog converter (DAC) functionality. In 2-bit operation, electro-optical (E/O) pulse-amplitude-modulation (PAM)-4 eye diagrams up to 20 GBd are demonstrated, in good agreement with E/O co-simulation results. The driver delivers a differential output swing of 4 Vpp across all 15 segments, dissipating 1.1 W of power, which translates into an energy consumption of 27.5 pJ/bit at 40 Gb/s.