Optical fibre transmission of the highest-order

In a paper published in Optics Express, TRANSNET researchers in collaboration with KDDI Research set a new record for achievable information rates of any standard optical transmission system to date.

Optical networks underpin the Internet, but to support an increasingly digital society and its constant demand for information, the amount of data transmitted across the network must increase. Every link in the network contains an optical transceiver, a key piece of optical hardware that strongly influences the data capacity of that link. To boost capacity, the transmission system can be tailored to make the best use of the transceiver, but with so many unique transceivers across global optical networks, the optimisation of every individual link is a serious challenge.

In a paper recently published in Optics Express, members of the TRANSNET team from UCL in collaboration with KDDI Research, propose a general technique to address this problem by combining geometric constellation shaping, a computational method used to increase the capacity of optical networks, with digital signal processing.

The team developed a geometrically shaped modulation format with 2048 constellation points, the largest ever demonstrated, designed to optimise the transmitted data for any given optical transceiver. With this approach, they were able to maximise the information rate of a standard transmission system without changing any of the optical hardware, making the technique applicable to any conventional setup in use today.

The research shows that it’s possible to customise each optical link in the network based on its unique transceiver to reach the highest achievable information rate possible. The proposed method would allow the capacity of optical networks to increase in order to support the global demand for data and keep the operating costs of an internet connection affordable.

The work was led by Yuta Wakayama from KDDI Research (Japan) and Thomas Gerard from UCL (led by TRANSNET PI Polina Bayvel) and was published on 1 June 2021 in Optics Express.

KDDI press release

2048-QAM transmission at 15 GBd over 100 km using geometric constellation shaping
Yuta Wakayama, Thomas Gerard, Eric Sillekens, Lidia Galdino, Domanic Lavery, Robert Killey and Polina Bayvel

For a full list of published TRANSNET research, including journal and conference papers, please take a look at our publications page.