We report a large area photo-diode based homodyne detector for free-space quantum coherent communication. The detector's performance is studied in terms of detection bandwidth and electronic noise for shot-noise limited quantum signal detection. Using large area photo-diodes increases signal collection efficiency from turbulent atmospheric channels, in comparison with typical fibre based free-space homodyne detectors. Under identical atmospheric turbulence and receiver aperture conditions, our homodyne detector based on 1mm diameter photo-diode experiences 0dB loss due to turbulence while a 10um fibre based detector experiences 13.5dB of signal loss over a 700km free-space link, at 90 degree elevation angle.
@article{arxiv.2011.03843,
title = {Increasing the link-distance of free-space quantum coherent communication with large area detectors},
author = {Rupesh Kumar and Igor Konieczniak and Gerald Bonner and Tim Spiller},
journal= {arXiv preprint arXiv:2011.03843},
year = {2020}
}