STL and Colt Successfully Trial Multi-Core Fiber in London, Advancing Next-Gen Optical Networks
India-based STL, a global provider of optical connectivity solutions, and Colt Technology Services have successfully completed field trials of multi-core fiber (MCF) technology on Colt’s London metro optical network, according to a recent announcement. The trial demonstrated that STL’s Multiverse™ four-core MCF can significantly increase per-fiber capacity while maintaining compatibility with existing infrastructure, offering a cost-efficient solution for carriers aiming to scale network capacity in space-constrained environments.
Validation of MCF Technology on Operational Networks
The trial, conducted on Colt’s metro network, tested STL’s MCF under both short-haul (9 km) and long-haul metro-regional (63 km) use cases. The MCF achieved a line rate of 800 Gbps, while successfully validating 100GE and 400GE interfaces, aligning with high-capacity demands for data center interconnects. In terms of design, STL’s MCF mimics conventional single-mode fiber (SMF) with the same 125 µm cladding diameter but integrates four independent cores, effectively multiplying spatial capacity without increasing cable size. This innovative architecture simplifies deployment for carriers by leveraging existing duct and cable designs.
Key performance metrics such as chromatic dispersion, polarization mode dispersion, inter-core crosstalk, and energy efficiency met expected benchmarks. These findings bolster confidence in MCF’s operational viability while offering a pathway for carriers to enhance network density without costly civil infrastructure upgrades.
Implications for Telecom Operators and Future-Ready Networks
The success of this trial has far-reaching implications for operators navigating growing bandwidth demand fueled by AI, cloud computing, and 5G deployments. Metro networks, which are often constrained by limited duct space and aging infrastructure, stand to benefit from MCF’s higher bit-per-duct and bit-per-mm² profile. By reducing the need for expensive and disruptive civil works, MCF presents a compelling route to achieving cost and energy efficiency in congested urban areas.
For STL, the trial reinforces their position as a leader in developing advanced optical connectivity solutions for the digital era. Industry analysts see this as further evidence of STL’s commitment to addressing the challenges of scaling networks for AI and cloud-driven digital services while managing capital and operational expenses effectively.
Expert Outlook and Broader Context
STL’s collaboration with Colt places it among the early adopters of space-division multiplexing (SDM) technology—a key enabler of next-generation networks. The ability to integrate seamlessly with brownfield infrastructure positions MCF as a practical solution for carriers worldwide. STL’s broader ecosystem, including fiber, cabling, and connectivity hardware, aligns with its strategy to deliver AI-ready and 5G-capable optical infrastructure.
This trial emphasizes the growing importance of joint innovation efforts between technology providers and carriers. As demand for AI workloads and hyperscale cloud services accelerates, such breakthroughs will be crucial in addressing the resulting bandwidth strain. According to STL’s CTO, Dr. Badri Gomatam, partnerships like this “accelerate adoption of next-generation connectivity technologies,” signaling a major shift in the industry’s approach to optical network modernization.
As operators around the world grapple with balancing capacity growth and sustainability, the success of trials like this could pave the way for widespread adoption of MCF technology. Is this the next big leap in optical networking?
