Researchers from IDLab, an Imec research group at Ghent University, Belgium, presents an optical receiver capable of 200Gbps data rate at the European Conference on Optical Communication (ECOC) on October 2. The approach combines a silicon germanium (SiGe) BiCMOS traveling-wave IC and a silicon photonics (SiPh) germanium photodetector, according to Imec, offering both scalability and speed to meet exploding data-rate needs from data centers.
Perter Ossieur, program manager for high-speed transceivers at IDLab, indicates that the highest performing optical datacom transceivers operate at speeds up to 800 Gbps, using 8 x 100 Gbps channels, but the industry is looking to double the channel capacity to 200 Gbps to reduce transceiver complexity, cost and power consumption while improving manufacturing yield. Ossieur's team has achieved a gross data rate of 200 Gbps by co-integrating a traveling-wave SiGe BiCMOS transimpedance amplifier with a SiPh Ge photodetector.
BiCMOS stands for Bipolar Complementary Metal-Oxide-Semiconductor, and features a combination of bipolar junction transistor (BJT) and CMOS technologies on a single IC. The integration of two different process technologies brings an unique advantage: bipolar transistors offer high speed and gain, thus suitable for high-frequency analog applications, while CMOS technology offers lower power consumption and scalability. According to Ossieur, an alternative to reach such speed are Indium Phosphide (InP) electronics, though the technology is less scalable and less affordable compared to BiCMOS. "SiGe BiCMOS allows us to integrate more functionalities and the chips can also be manufactured at higher volumes."
Notably, the SiPh Ge photodetector comes from Imec's integrated SiPh platform, known as iSiPP. According to Joris Van Campenhout, program director optical I/O at Imec, the new optical receiver represents one of the many steps Imec is taking to ready its SiPh platforms for demanding 200Gbps-and-beyond applications, and the latest results represent the capability of iSiPP to operate at lane rates of 200GBps - a key requirement for upcoming pluggable and co-packaged optics.
