Open Access50 GBd PAM4 transmitter with a 55nm SiGe BiCMOS driver and silicon photonic segmented MZM
Author(s) -
Laurens Breyne,
Hannes Ramon,
Kasper Van Gasse,
Michiel Verplaetse,
Joris Lambrecht,
Michael Vanhoecke,
Joris Van Campenhout,
Günther Roelkens,
Peter Ossieur,
Xin Yin,
Johan Bauwelinck
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.397765
Subject(s) - transmitter , bicmos , bandwidth (computing) , photonics , silicon photonics , electronic engineering , limiting , optoelectronics , optics , electrical engineering , computer science , voltage , physics , telecommunications , engineering , channel (broadcasting) , transistor , mechanical engineering
We demonstrate an optical transmitter consisting of a limiting SiGe BiCMOS driver co-designed and co-packaged with a silicon photonic segmented traveling-wave Mach-Zehnder modulator (MZM). The MZM is split into two traveling-wave segments to increase the bandwidth and to allow a 2-bit DAC functionality. Two limiting driver channels are used to drive these segments, allowing both NRZ and PAM4 signal generation in the optical domain. The voltage swing as well as the peaking of the driver output are tunable, hence the PAM4 signal levels can be tuned and possible bandwidth limitations of the MZM segments can be partially alleviated. Generation of 50 Gbaud and 53 Gbaud PAM4 yields a TDECQ of 2.8 and 3.8 dB with a power efficiency of 3.9 and 3.6 pJ/bit, respectively; this is the best reported efficiency for co-packaged silicon transmitters for short-reach datacenter interconnects at these data rates. With this work, we show the potential of limiting drivers and segmented traveling-wave modulators in 400G capable short-reach optical interconnects.