Optical interconnects are short optical links used for interconnecting various types of computer systems. From the ultra-short connections on optical motherboards and backplanes to the tens-of-meters-long Active Optical Cables interconnecting servers in datacenters and even up to the few-kilometer-long links found in campus networks, optical interconnects is the technology of choice by virtue of their unique bandwidth-distance product that outperforms electrical links by far. Research into optical interconnects goes way back and includes the prototypical demonstration of simple optical switching fabrics and optical computing machines in the early 1990s. Nowadays technological progress in photonic integration and materials engineering has pushed capacity, throughput and interconnect port density by orders of magnitude, putting optical interconnects in the spotlight for meeting the soaring demand for bandwidth. As photonics technologies are rapidly maturing, what was once considered as a niche technology for high performance computing systems is now finding its way to a manifold of applications, ranging from Active Optical Cables in server farms delivering a stunning 400 Gb/s, all the way to consumer electronics like the optical USB operating at 5 Gb/s and bringing unprecedented performance to our fingertips. With cloud applications raising the bar for rapid communication with vast capacity, optical interconnects is the outright enabler and the backbone of our information-centric society.
PCRL has been involved and lead research in optical interconnects through innovative concept definition, subsystem design, evaluation and valorization. The group is active in ultra-high capacity, flexible transceiver development, optical backplanes, on-chip interconnects and active optical cable systems. Ongoing research topics include advanced modulation formats, concept transformation to PIC designs over silicon on insulator, silicon nitride and polymer integration platforms and optical switching architectures.