The optical networks interconnecting datacenters (DCI) have grown the last decade more than any other transport network and have motivated the evolution of the original Internet architecture and of the global fiber infrastructure [1, 2, 3]. The current growth is also projected to continue strong by at least 2 more orders of magnitude [3, 4], placing DCI at the frontier of optical fiber communications. This presentation offers an industry perspective on DCI-motivated innovations and challenges in optical systems and photonics technology. Notably, photonic integration combined with coherent WDM and advancements in DSP and Moore's law, is enabling current DCI systems to operate ever closer to the fiber Shannon limit by exceeding 6 b/s/Hz spectral-efficiency in transatlantic deployments or reaching 25 Gb/s per Watt power-efficiency in metro DCI 400GE pluggable coherent WDM transceivers [1, 3].
1. L. Paraschis et al "Innovations in Inter Data Center Transport Networks", Chapter 15 (pp. 673 - 718) in Optical Fiber
Telecommunications VII, Edited by Alan E. Willner, Elsevier, ISBN 978-0128165027 (2019).
2. L. Paraschis, "Advancements in Metro Regional and Core Transport Network Architectures for the Next-Generation
Internet", Chapter 18 (pp. 793–817) in Optical Fiber Telecommunications VI Volume B, Systems and Networks, Edited by
Ivan Kaminow, Tingye Li, Alan E. Willner, Elsevier, ISBN 978-0123969606 (2016).
3. U. Holzle, "A Ubiquitous Cloud Requires a Transparent Network", IEEE/OSA Conference on Optical Fiber Communications
(OFC), Plenary (2017), and V. Vusirikala, "SDN Enabled Programmable, Dynamic Optical Layer", European Conference on
Communications (ECOC), Plenary (2017).
4. James Hamilton, "How Many Data Centers Needed World-Wide", https://perspectives.mvdirona.com/2017/04/how- manydata-centers-needed-world-wide (last accessed 2021/01/24).