Open AccessFree-space quantum key distribution in urban daylight with the SPGD algorithm control of a deformable mirror
Author(s) -
Yun-Hong Gong,
Kui-Xing Yang,
Hai-Lin Yong,
Jian-Yu Guan,
Guo-Liang Shentu,
Chang Liu,
Fengzhi Li,
Yuan Cao,
Juan Yin,
Sheng-Kai Liao,
Ji-Gang Ren,
Qiang Zhang,
Cheng-Zhi Peng,
Jian-Wei Pan
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.018897
Subject(s) - quantum key distribution , daylight , computer science , optics , free space optical communication , key (lock) , noise (video) , signal to noise ratio (imaging) , quantum cryptography , physics , quantum , algorithm , photon , optical communication , quantum information , computer vision , image (mathematics) , computer security , quantum mechanics
Free-space quantum key distribution (QKD) is important to realize a global-scale quantum communication network. However, performing QKD in daylight against the strong background light noise is a major challenge. Here, we develop the stochastic parallel gradient descent (SPGD) algorithm with a deformable mirror to improve the signal-to-noise ratio (SNR). We then experimentally demonstrate free-space QKD in the presence of urban daylight. The final secure key rate of the QKD is 98∼419 bps throughout the majority of the daylight hours.