The design of entangled source for free space quantum communications
Wang Shao-Kai, Ji-Gang Ren, Jin Xian-Min, Yang Bin, Yang Dong, Peng Cheng-Zhi, Jiang Shuo, Xiang‐Bin Wang, (1)清华大学物理系,北京 100084; (2)中国科学技术大学近代物理系,合肥 230026 · Acta Physica Sinica · 2008
We design and build an entanglement source suitable for free space quantum communications experiment. The coincidence counting rate after single mode fiber is 20000 cps. The entanglement visibility is more than 95% in horizontal vertical base and more than 90% in diagonal base. The Bell inequality was broken by more than 100 standard deviations in local experiment. The entanglement source satisfies the requirements for 20 km free space quantum communications experiment.