Robert Griffin, Oclaro, UK; Tom Issenhuth, Microsoft, USA
Coherent systems are widely deployed for high capacity long-haul networks, whereas direct detection (DD) implementations with low cost and low power consumption dominate short reach. Both approaches overlap in new fast-growing applications of short reach Metro and data center interconnects (DCI), requiring DWDM transport over distances around 100 km. In 2016 a commercial 100G PAM4 DD solution for 80km DWDM DCI was announced, and single-carrier 400G coherent solutions targeting similar applications have been demonstrated by multiple vendors. Will these solutions happily coexist, will one become the dominant solution over time, or will new alternatives become available? The panel will discuss the merits of different approaches and what progress we can expect as the technologies develop.