Decoy state quantum key distribution with dual detectors heralded single photon source
Mi Jing-Long, Wang Fa-Qiang, Lin Qing-Qun, Ruisheng Liang, Songhao Liu, 华南师范大学信息光电子科技学院，光子信息技术广东省高校重点实验室，广州 510631 · Acta Physica Sinica · 2008
Decoy state has recently been proved as a useful method for substantially improving the performance of quantum key distribution (QKD). Considering the imperfect extinction ratio and the spontaneous emission of the practical Laser, vacuum states are not prepared easily. So in this paper, the optimal situation of the decoy state protocol applied to the QKD system with heralded single photon source (HSPS) is complemented and extended. The two weak decoy state protocol and the one decoy state protocol are proposed. At last, the theory of “dual detectors" is combined with the QKD system with HSPS. In the simulation, the secure distance is up to 2215 km, which is approximately 50 km more than that of the on-off detectors.