Towards the neW era of 1.6 Tb/s System-In-Package transceivers for datacenter appLIcations exploiting wafer-scale co-inteGration of InP membranes and InP-HBT elecTronics
[December 2019 – November 2023]
PCRL coordinated the TWILIGHT Project. The rise of IoT, 5G, and cloud applications led to a massive increase in datacenter traffic, driving demand for 400GbE and the ratification of 800GbE and 1.6T standards, which were expected between 2013 and 2015. Datacenter operators had to keep pace with increasing speeds while managing the rising power consumption required for airflow management and cooling. Additionally, they needed to address the extensive interconnectivity between servers and switches required for 5G ultra-low latency applications.
100Gb/s per lane became the next step for realizing 800GbE modules, marking the transition from pluggable optics to co-packaged optics with ASICs, paving the way to 1.6T and beyond. TWILIGHT aimed to leverage InP membranes and InP-HBT electronics at unprecedentedly close distances (<20μm) to unlock the full speed potential of its high-performance components and enable 112Gbaud per lane.
Through wafer-scale bonding, high-accuracy assembly, and co-packaging concepts, TWILIGHT’s optoelectronic engines achieved capacities of up to 1.6T. Selective area growth was utilized to develop C-band and O-band EMLs and UTC photodiodes, integrating them with echelle gratings on the same system-on-chip platform. The adaptation of the SAG layer stack enabled the development of polarization-insensitive SOAs, allowing for complex functionalities on-chip.
TWILIGHT leveraged analog bandwidth interleaving to interface its transceivers with next-generation 112G SERDES and developed analog (de)multiplexers, >110GHz linear drivers, and 100GHz TIAs. Additionally, it utilized PI-SOAs to create 4×4 and 16×16 optical space switches with nanosecond latency and a >50% smaller footprint.
The O-band and C-band SiP transceiver demonstrators achieved up to 72% and 74% power consumption savings, respectively, compared to established technologies. They targeted the datacenter market (2–10 km) and DCI (<40 km) at an estimated cost of 0.89€/Gb/s. TWILIGHT’s technologies were exploited through its industrial partner, MLNX.
