Shashank Kumar
visits VQCC.

From 21 June to 25 July 2026, Shashank Kumar, an MSCA QSI doctoral researcher at the University of Geneva, carried out a research visit at VQCC in Vigo.

During his stay, Shashank contributed to the implementation and experimental validation of a high-speed polarization encoder for quantum key distribution (QKD). Based on a balanced Sagnac-loop architecture, the system can encode at repetition rates of up to 1 GHz and generate polarization states in the X and Z bases.

The results obtained during the visit demonstrated the potential of this approach for high speed polarization encoding. The setup will now undergo further optimization to improve its timing, polarization stability, and extinction ratio, supporting VQCC’s future development of polarization-based free-space quantum communication links and optical ground-station experiments.