Post-deadline Paper on the 42nd European Conference on Optical Communications (ECOC16')

(22-10-2016) Post-deadline Paper: First Demonstration of Real-Time 100 Gbit/s 3-Level Duobinary Transmission for Optical Interconnects

Datacenters require ultra-high-speed optical interconnects between servers to support applications such as high performance computing, network virtualization, social media, and the Internet of Things. For this purpose, the interconnect speed needs to scale up drastically from today’s 100 Gigabit Ethernet (GbE), implemented by four parallel streams of 25Gbit/s, towards 400GbE. Among different approaches, a 4-lane 100Gbit/s scheme is particularly attractive for deployment in 500m and 2km single-mode fiber applications.

However, scaling single-lane data rates towards 100Gb/s involves huge technical challenges for the transceiver circuits and signal processing to overcome the bandwidth limitations in the signal path between the transmitter and receiver circuits. So far, only a few teams managed to demonstrate such fast links without relying on expensive equipment and offline digital signal processing. As such, our work presented in this post deadline paper is among the first real-time demonstrations of a 100Gb/s optical link where all the signal generation and signal processing is done in real-time with custom dedicated integrated circuits. Taking advantage of the reduced bandwidth requirements for duobinary signaling, a more energy efficient approach was developed as an alternative to traditional non-return-to-zero (NRZ) on-off keying and 4-level pulse amplitude modulation (PAM).

The transceiver development is part of an UGent-imec spin-off incubation program, more info on www.bifast.io. The demonstration and test bed integration was a collaboration between UGent-imec IDLab, KTH Royal Institute of Technology (Stockholm) and Acreo Swedish ICT, who provided the externally modulated laser (EML) module.

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