Beyond Exabit Optical Communications: Towards Transceiver Integration
Funder: UK Research and Innovation
Lead partner: UCL
Partners: Corning Inc.; Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut; National Institute of Information and Communications Technology; OFS Fitel, LLC
Lead academic: Dr Filipe Marques Ferreira
Project amount: £708,738
Research themes: Future Communications; AI & Intelligent Systems
Project period: 1 November 2024 - 31 October 2027
Project description: The aim of this fellowship is to develop disruptive approaches through theory and experiment to unlock the capacity of future information systems. To go beyond current optical fibre channel limits is arguably the greatest challenge faced by digital optical communications. To target it, the proposed research will combine techniques from information theory, coding, higher-dimensional modulation formats, digital signal processing, advanced photonic design, and machine learning to make possible breakthrough developments to ensure a robust communications infrastructure beyond tomorrow. Optical communications have to-date been able to fulfil the ever-growing data demand whilst simultaneously reducing cost and energy-per bit. However, optical communications have now exceeded the fundamental capacity of existing single-mode technology a trend leading to a rapid duplication of line systems which in time will translate in less affordable broadband access.
To meet future demands with prospective cost and energy savings and avoid the impending exhaust of fibre capacity, this fellowship offers a scalable path towards parallelism in optical fibre communications resembling the advent of parallel computing using multiple cores to sustain Moore’s law - once we were unable to double the number of transistors in a single-core microprocessor. The emergent technology of spatial division multiplexing (SDM) provides much wider conduits of information by offering additional means for transporting channels over one single fibre, using multi-mode and multi-core fibres. The fellow has shown that the internal structure of optical fibres can be optimised to support thousands of different spatial paths, each with full transmission capacity. And, critically, that there are principal launching conditions that allow for full transmission rate over each path with a small fraction of the equalisation cost assumed before. These discoveries offer the potential to foster a revolution in how optical fibre communications networks operate to meet the ever-increasing traffic demand with decreasing cost and energy consumption per bit, enabling ubiquitous and universal broadband access.
This fellowship renewal envisages how to achieve chip-scale integration for multimode SDM transceivers packing intelligent optical beamforming powered by generalised machinelearning and principled digital signal processing for highly spatially diverse fibre channels. Moreover, this fellowship renewal will initiate a new class of low crosstalk multi-mode fibres using elliptical cores and a new class of multimode optical fibre amplifiers with adaptive mode gain profile - opening fundamentally new theoretical and experimental possibilities up to now unexplored for SDM systems. These new developments will push multimode SDM technology far beyond that of the standard single-mode fibre infrastructure and bring it to an industry-ready development stage, unlocking decades of capacity growth in future optical networks with sustainable cost- and energy-per-bit
