We demonstrate a compact, high-isolation C-band optical ground terminal for satellite QKD, achieving more than 120 dB daylight background suppression and 135 dB crosstalk noise isolation. Successful QKD over an outdoor 100m FSO validate its feasibility for integration of satellite-QKD with urban fiber segments.
@article{arxiv.2509.07667,
title = {SMF Coupled Compact Ground Terminal with Advanced Filtering Towards Daylight C Band Satellite QKD},
author = {Argiris Ntanos and Aristeidis Stathis and Panagiotis Kourelias and Evridiki Kyriazi and Panagiotis Toumasis and Nikolaos K. Lyras and Nikolaos Makris and Sotirios Tsavdaridis and E. M. Xilouris and Athanasios Marousis and Ilias Papastamatiou and Athanasios D. Panagopoulos and Konstantinos Vyrsokinos and Kleomenis Tsiganis and George T. Kanellos and Hercules Avramopoulos and Giannis Giannoulis},
journal= {arXiv preprint arXiv:2509.07667},
year = {2025}
}