STL, in collaboration with India’s Centre for Development of Telematics (C-DOT), has successfully demonstrated India’s first quantum key distribution (QKD) transmission over a 100-kilometer, 4-core Multi-Core Fibre (MCF) network. This achievement, conducted at the Department of Telecommunications’ Advanced Optical Communications Test Bed at IIT-Madras, marks a major milestone in the development of quantum-secured communication infrastructure and positions India at the forefront of secure digital networking.
STL’s end-to-end deployment included both underground and aerial MCF cable networks, making it the first company globally to implement this technology across both environments. The QKD demonstration utilized one core for quantum signal transmission while the remaining three cores carried high-speed classical data, proving that MCF can support simultaneous quantum and traditional data communication without interference. This eliminates the traditional need for a dedicated dark fibre for QKD, significantly improving scalability and cost-efficiency for real-world deployments.
The successful integration of quantum communication and high-capacity classical data in a single fibre validates the readiness of this infrastructure for India’s 5G and 6G future. STL and C-DOT’s collaborative work addresses critical challenges in quantum networking, enabling secure, scalable communication networks essential for a digitally sovereign India.
- STL and C-DOT demonstrate QKD transmission over 100km 4-core Multi-Core Fibre
- First deployment in India combining quantum and classical data on a single fibre
- MCF enables physical separation of quantum and classical signals, eliminating the need for dark fibre
- STL deployed both aerial and underground MCF networks; the first to do so globally
- Demonstration supports future 5G/6G infrastructure and scalable, secure digital communication
“We have demonstrated how cutting-edge optical innovations can revolutionise secure communication by successfully integrating QKD with our indigenously developed MCF,” said Rahul Puri, CEO – Optical Networking Business, STL.