Lisbon is set to become a global hub for fiber optic innovation with the installation of the world’s largest multicore fiber (MCF) terrestrial testbed. This pioneering initiative is led by Adolfo Cartaxo, professor and researcher at the Instituto de Telecomunicações - Iscte and is funded by Iscte University in partnership with a regional public institution. The project is proudly developed in close partnership with Metropolitano de Lisboa, whose support is pivotal to its success, and with Heraeus Covantics, a leading German company specializing in high-purity quartz products for fiber optic manufacturing.

Key partners also include Telcabo, responsible for installing the multicore fiber cable, and Tratos Cavi, an Italian group supplying the protective cable that encases the fibers.

A Unique Underground Test Environment

The testbed is being installed along the Yellow Line of the Lisbon Metro, offering a rare opportunity to test fiber optics in a live, underground environment.

“Tests are carried out inside the tunnels of an operating metro line, exposing the cables to vibrations, temperature changes, humidity, noise, and constant movement,” explains Adolfo Cartaxo, technical lead of the project.

The system will be monitored from the Optical Communications Laboratory at Iscte building, which serves as both the starting point of the cable network and the hub for all testing activities. The infrastructure includes a multicore fiber cable with 144 strands, featuring 74 multi-core optical fibers: 64 with four cores and 10 with seven cores, totaling 326 data transmission channels. Once interconnected, 728 kilometers may be spanned with the same multicore fibre type, equivalent to 28 full loops along a 26 km ring, based on the 13 km stretch between Odivelas and Largo do Rato stations.

Open Access for the Scientific Community

Within just a few months, the system will be fully operational and open to the global scientific community. To the best of our knowledge, this will be the longest deployed terrestrial multicore fiber ring ever reported.

This open-access testbed offers an exceptional opportunity to test cutting-edge MCF technologies, serving as a breakthrough platform for validating new components, equipment, and applications.