C-DOT & STL Achieve India’s First QKD Over Multi-Core Fibre

18 Apr 2025 CW Team

Multi-Core Fibre technology enables simultaneous transmission of data across multiple cores within a single fibre, significantly reducing physical space and infrastructure costs. Notably, QKD traditionally requires a dedicated dark fibre for quantum signal transmission. However, this achievement marks a paradigm shift, as MCF allows for the physical separation of quantum and classical signals within the same fibre — with one core carrying quantum signals and the remaining cores supporting high-speed user data.

In this pioneering trial, quantum signals were transmitted through one core, while classical high-capacity data travelled through the other three cores, with a stable QKD link successfully maintained over a distance exceeding 100 km. This demonstrates the robustness and integrity of quantum communication even under concurrent classical data transmission, thereby enhancing the practicality and cost-efficiency of quantum-secured networks.

C-DOT, India’s premier telecom R&D centre under the Department of Telecommunications (DoT), has developed and deployed industry-grade QKD systems that have received Technology Approval from the Telecommunication Engineering Centre (TEC). This latest accomplishment further strengthens its role in advancing the country’s quantum ecosystem.

Sterlite Technologies Ltd. (STL), a global leader in optical networking solutions, has pioneered the development of Multi-Core Fibre leveraging Space Division Multiplexing to significantly increase transmission capacity. With a presence in over 100 countries and 10+ global manufacturing plants, STL remains at the forefront of building future-ready, scalable digital infrastructure.

Commenting on the success, Dr Rajkumar Upadhyay, CEO, C-DOT, remarked, “This initiative marks a key milestone for India’s telecom ecosystem. It establishes the feasibility of integrated quantum-classical networks over next-gen optical fibres, drastically reducing QKD deployment costs.”

Rahul Puri, CEO, Optical Networking Business, STL, added, “This breakthrough collaboration with C-DOT highlights India’s advancing capabilities in secure digital infrastructure. By integrating QKD with STL’s indigenous MCF technology, we are setting a new benchmark in secure communication and global optical leadership.”

Both C-DOT and STL reaffirm their commitment to strengthening India’s position in the global quantum and optical networking landscape. This achievement lays a vital foundation for building a cost-effective, secure, and resilient national quantum communication infrastructure

In a landmark milestone for India's digital and quantum future, the Centre for Development of Telematics (C-DOT), in collaboration with Sterlite Technologies Limited (STL), has achieved the nation’s first successful Quantum Key Distribution (QKD) transmission over a 4-core Multi-Core Fibre (MCF). This breakthrough underscores India's growing capabilities in the realm of quantum-secured communication networks. Multi-Core Fibre technology enables simultaneous transmission of data across multiple cores within a single fibre, significantly reducing physical space and infrastructure costs. Notably, QKD traditionally requires a dedicated dark fibre for quantum signal transmission. However, this achievement marks a paradigm shift, as MCF allows for the physical separation of quantum and classical signals within the same fibre — with one core carrying quantum signals and the remaining cores supporting high-speed user data. In this pioneering trial, quantum signals were transmitted through one core, while classical high-capacity data travelled through the other three cores, with a stable QKD link successfully maintained over a distance exceeding 100 km. This demonstrates the robustness and integrity of quantum communication even under concurrent classical data transmission, thereby enhancing the practicality and cost-efficiency of quantum-secured networks. C-DOT, India’s premier telecom R&D centre under the Department of Telecommunications (DoT), has developed and deployed industry-grade QKD systems that have received Technology Approval from the Telecommunication Engineering Centre (TEC). This latest accomplishment further strengthens its role in advancing the country’s quantum ecosystem. Sterlite Technologies Ltd. (STL), a global leader in optical networking solutions, has pioneered the development of Multi-Core Fibre leveraging Space Division Multiplexing to significantly increase transmission capacity. With a presence in over 100 countries and 10+ global manufacturing plants, STL remains at the forefront of building future-ready, scalable digital infrastructure. Commenting on the success, Dr Rajkumar Upadhyay, CEO, C-DOT, remarked, “This initiative marks a key milestone for India’s telecom ecosystem. It establishes the feasibility of integrated quantum-classical networks over next-gen optical fibres, drastically reducing QKD deployment costs.” Rahul Puri, CEO, Optical Networking Business, STL, added, “This breakthrough collaboration with C-DOT highlights India’s advancing capabilities in secure digital infrastructure. By integrating QKD with STL’s indigenous MCF technology, we are setting a new benchmark in secure communication and global optical leadership.” Both C-DOT and STL reaffirm their commitment to strengthening India’s position in the global quantum and optical networking landscape. This achievement lays a vital foundation for building a cost-effective, secure, and resilient national quantum communication infrastructure

Infrastructure Energy

17 Dec 2025

Vedanta Aluminium Uses 1.57 bn Units of Green Energy in FY25

Vedanta Aluminium, India’s largest aluminium producer, recently reported consumption of 1.57 billion units of renewable energy in FY25, marking a significant milestone in its 2030 decarbonisation roadmap. The company also achieved an 8.96 per cent reduction in greenhouse gas (GHG) emissions intensity compared to FY21, reinforcing its leadership in India’s low-carbon manufacturing transition. During FY25, Vedanta Aluminium expanded its renewable energy portfolio through long-term power purchase agreements, strengthening its strategy to source nearly 1,500 MW of renewable power over the lon..

Real Estate

17 Dec 2025

Oberoi Group to Develop Luxury Resort at Makaibari Tea Estate

EIH Limited, the flagship company of The Oberoi Group, has announced the signing of a management agreement to develop an Oberoi luxury resort at the iconic Makaibari Tea Estate in Darjeeling. The project marks a key milestone in the Group’s long-term strategy of creating distinctive hospitality experiences in rare and environmentally significant locations. Established in 1859, Makaibari is one of the world’s oldest tea estates and is globally recognised for its Himalayan landscape, primary forests and exceptional biodiversity. Spread across 1,236 acres, the estate houses one of the world�..

Real Estate

17 Dec 2025

GHV Infra Secures Rs 1.09 Bn EPC Order in Jamshedpur

GHV Infra Projects Ltd, a fast-growing EPC company in India’s infrastructure and construction sector, has recently secured a Rs 1.09 billion work order in Jamshedpur, Jharkhand. Awarded by a reputed group entity, the contract covers end-to-end civil construction, mechanical, electrical and plumbing (MEP) systems, along with high-quality finishing works for a large building development. The project will be executed over a 30-month period, with defined benchmarks for quality, safety and timely delivery. The order strengthens GHV Infra’s footprint in Jamshedpur, a key industrial hub known fo..