The passive approach to quantum key distribution (QKD) consists of removing all active modulation from the users' devices, a highly desirable countermeasure to get rid of modulator side-channels. Nevertheless, active modulation has not been completely removed in QKD systems so far, due to both theoretical and practical limitations. In this work, we present a fully passive time-bin encoding QKD system and report on the successful implementation of a modulator-free QKD link. According to the latest theoretical analysis, our prototype is capable of delivering competitive secret key rates in the finite key regime.
@article{arxiv.2304.11655,
title = {Experimental demonstration of fully passive quantum key distribution},
author = {Feng-Yu Lu and Ze-Hao Wang and Víctor Zapatero and Jia-Lin Chen and Shuang Wang and Zhen-Qiang Yin and Marcos Curty and De-Yong He and Rong Wang and Wei Chen and Guan-Jie Fan-Yuan and Guang-Can Guo and Zheng-Fu Han},
journal= {arXiv preprint arXiv:2304.11655},
year = {2023}
}