A Monolithically Integrated Segmented Linear Driver and Modulator in EPIC 0.25- μ m SiGe:C BiCMOS Platform

In this paper, a monolithically integrated segmented linear driver and Mach-Zehnder modulator (MZM) are presented. The transmitter is fabricated in electronic-photonic integrated circuit 0.25-μm SiGe:C BiCMOS technology, with fT/fmax= 190 GHz. The driver and the modulator are divided into 16 segments and the MZM phase shifter has a total length of 6.08 mm. The segmented driver delivers a maximum of 4 Vppdifferentially, featuring a gain of 13 dB and total harmonic distortion below 5%. Electro-optical time-domain measurements using PAM-4 modulation format are performed, demonstrating optical eye-diagrams up to 25 Gbaud. The electro-optical bandwidth of the transmitter is 18 GHz. The power dissipation of the driver is 1.5 W, resulting in an energy per bit of 30 pJ/bit at 50 Gb/s. The reported optical transmitter demonstrates for the first time an implementation of a linear driver integrated with an MZM in a Si monolithic process.