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 250nm IHP SiGe BiCMOS ePIC monolithic process, combining both electronics and photonics on the same silicon substrate, including HBTs featuring ft/fmax of 210 /290GHz and silicon depletion phase shifters. The designed modulator consists of 8-segments, each driven by a three stages amplifier, which delivers 4Vpp 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 450mW 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.