A 25 Gb/s, 4.4 V-Swing, AC-Coupled Ring Modulator-Based WDM Transmitter with Wavelength Stabilization in 65 nm CMOS Hao Li, Student Member , IEEE , Zhe Xuan

Abstract

Silicon photonics devices offer promising solution to meet the growing bandwidth demands of next-generation interconnects. This paper pre sents a 5 × 25 Gb/s carrier-deple- tion microring-based wavelength-division multiplexing (WDM) transmitter in 65 nm CMOS. An AC-coupled differential driver is proposed to realize 4 × VDD output swing as well as tunable DC-biasing. The proposed transmitter incorporates 2-tap asym- metric pre-emphasis to effectivel y cancel the optical nonlinearity of the ring modulator. An average-power-based dynamic wave- length stabilization loop is also demonstrated to compensate for thermal induced resonant wavelength drift. At 25 Gb/s operation, each transmitter channel consumes 113.5 mW and maint ains 7 dB extinction ratio with a 4.4 V output swing in the presence of thermal fluctuations.