Bidirectional wavelength-division multiplexing transmission over installed fibre using a simplified optical coherent access transceiver

Abstract

High-speed broadband services require optical fibres in access networks, in which multiple subscribers are connected to service providers, to satisfy the continuously growing bandwidth demand. The primitive signaling scheme used in access networks enables the use of low-cost equipment but diminishes the bandwidth available to end-users. Thus, current technology will be unable to support future broadband demands. Coherent communication systems offer significantly improved power- and bandwidth-efficiency, but require fundamental simplifications to become economically viable for access networks. Here, we demonstrate a promising simplified coherent receiver exhibiting a robust performance against polarisation fluctuations over an installed fibre network. It enables the realisation of high-order modulation formats and offers high sensitivities, achieving a four-fold increase in the supported number of subscribers and approximately doubling the transmission distance compared to the recently standardized access technology. The proposed solution indicates that digital coherent technology can be feasible and transform the access networks, enabling ubiquitous new services and applications with uncontended, multi-gigabits/user broadband connections.This work was supported by the EPSRC Programme Grant UNLOC EP/J017582/1, and EP/J008842/1. Dr. Domaniç Lavery thanks the Royal Academy of Engineering under the Research Fellowships scheme for funding his fellowship. We also wish to acknowledge Dr. Will Yang and the EPSRC National Dark Fibre Infrastructure Service (NDFIS) NS/A000021/1 for providing access to the Aurora2 dark fibre network. We would like to thank Arın Lavery for his contribution to Fig.1