STL, a leader in optical and digital solutions, in collaboration with the Centre for Development of Telematics (C-DOT), has successfully demonstrated India’s first Quantum Key Distribution (QKD) transmission over a 100-k, 4-core multi-core fibre (MCF) network. This milestone represents a critical advancement in building India’s quantum-secured, future-ready communication infrastructure.

This breakthrough was achieved at the Advanced Optical Communications (AOC) Test Bed at IIT-Madras, sponsored by the Department of Telecommunications (DoT) and aligned with Telecommunication Engineering Centre (TEC) standards. STL’s homegrown MCF cable, designed for both aerial and underground deployment, served as a fully integrated end-to-end solution, including cabling, connectivity, and installation.

By transmitting quantum signals through one core and high-speed classical data through the other three, STL and C-DOT have successfully enabled simultaneous transmission without compromising the integrity of the quantum channel. This dual-capability solution enhances both security and efficiency, addressing two major challenges in quantum communication—form factor limitations and the exponential rise in data traffic.

This achievement places STL and C-DOT at the forefront of secure digital infrastructure innovation, bringing India closer to realizing scalable and secure quantum communication networks.