The future of optical interconnects for data centers: A review of technology trends

It is widely argued that optical transmission and switching technologies will play an important role in next generation data centers. However, even though optical technologies have made a lot of progress in the last years towards achieving very high transmission capacity as well as increased flexibility and efficiency, an additional effort needs to be put in determining and analyzing suitable architectures and technologies for powerful and future-proof optical intra- and inter-data center networks. This paper gives an overview on recent and future trends in technologies and architectures for optical transmission and switching with respect to their suitability to implement high-performance optically switched interconnects. It provides a look at the entire system while considering various hierarchical levels - from small-scale interconnects on a single chip to system-level rack-to-rack interconnection networks - and discusses design considerations and future research directions towards advanced optical interconnects.