Broadband and Power-Efficient Optoelectronic Transmitter Monolithically Integrated in a SiGe BiCMOS ePIC Technology

This paper presents a broadband and power-efficient monolithically integrated optoelectronic transmitter based on a segmented Mach-Zehnder modulator. The chip has been fabricated in the 250 nm IHP SiGe BiCMOS ePIC monolithic process, combining both electronics and photonics on the same silicon substrate, including HBTs featuring ft/fmax of 210/290 GHz and silicon depletion phase shifters. The designed modulator consists of 8-segments, each driven by a three stages amplfier, which delivers 4 Vpp in order to achieve a sufficient extinction ratio, accordingly to the modulation efficiency of the modulator. Electro-optical small-signal measurements showed bandwidth of 45 GHz. Time-domain measurements showed NRZ data-rates up to 64 Gbit/s from an overall power consumption of 450 mW and a power efficiency of 7.1 pJ/bit, resulting in the most efficient Mach-Zehnder modulator based transmitter that can be found in the literature in a monolithic process.