STL showcases multi-core fibre at Connected Britain

Author: Joe Peck

STL, an optical and digital systems company, has demonstrated its Unitube Single Jacket Indoor Optical Fibre Cable with four-core multi-core fibre (MCF) at Connected Britain 2025.

The technology places four cores within the same cladding diameter as standard single-mode fibre, maintaining a coating size of 250/200 micrometres.

STL is among the first companies to show real-world deployments of MCF technology, with use cases spanning underground and duct networks. Building on this work, the new cable has been designed specifically for indoor environments such as data centres, campus networks, and commercial buildings.

Fire safety and performance features

The cable is certified under the Construction Products Regulation (CPR) EuroClass Cca-s2, d1, a1 standard, providing a high level of fire resistance for critical infrastructure.

STL has also developed optical distribution units and connectivity solutions to complement the product, aiming to simplify integration into existing network architectures.

Key features of the indoor cable include:

• Enhanced security — support for quantum key distribution (QKD) to enable tamper-evident encryption
• Future-ready bandwidth — four times the throughput of legacy fibres, supporting applications such as AI, 5G, and quantum technologies
• Compact design — higher fibre counts within a smaller footprint, with examples including 864 fibres scaled to 3,456 using MCF
• Scalability — a single deployment providing higher backbone capacity for long-term use

Dr Badri Gomatam, CTO at STL, comments, “Through continuous innovation and global partnerships, STL is accelerating the adoption of advanced optical technologies.

“Our Unitube Single Jacket Indoor Optical Fibre Cable with MCF is engineered to meet the growing demands of high-capacity, secure, and future-ready networks.

“With our ongoing global standardisation efforts and real-world deployments, we are proud to lead the evolution of optical infrastructure that powers next-generation applications.”