Overcoming atmospheric turbulence effects in urban environment for quantum optical communication networks

This project aims to develop a robust urban quantum communication channel by addressing one of the main challenges of free-space optical links: atmospheric turbulence. Quantum networks enable secure communications via quantum key distribution (QKD), but urban environments present significant obstacles due to dynamic atmospheric conditions.
The research, a collaboration between the QComms Lab at the Universitat de Barcelona (UB) and La Salle–Universitat Ramon Llull (URL), focuses on establishing a 2.7 km optical quantum link between both institutions. The project will develop a Portable Intelligent Stabilization Unit (ISU) to mitigate beam distortions caused by turbulence, ensuring reliable quantum transmission. The ISU integrates Adaptive Optics (AO) and Machine Learning (ML) techniques to optimize photon detection fidelity.
The work plan consists of four phases:
1.Lab-based turbulence simulation – Constructing and characterizing a controlled turbulence chamber to study optical distortions.
2.Development of the ISU – Designing a portable system with fast-moving optical elements for real-time turbulence correction.
3.Quantum light injection – Calibrating the ISU with single-photon beams to validate its performance.
4.Urban implementation – Deploying the ISU at the receiving end of the optical quantum link between UB and URL.
This project pioneers free-space quantum communication in urban settings, providing a scalable and flexible model for future city-wide quantum networks. The outcomes will contribute to the advancement of quantum-secure communication, setting the foundation for broader metropolitan and satellite-based quantum networks.