TY - Chin. Phys. Lett. A1 - LI Gang, LI Li-Ping, DU Zhi-Jing, LIU Tao, ZHANG Tian-Cai, WANG Jun-Min T1 - Ultra-Low Mean-Photon-Number Measurement with Balanced Optical Heterodyne Detection Y1 - 2004-04-01 JF - Chinese Physics Letters JO - Chin. Phys. Lett. SP - 671-674EP - 674 VL - 21 IS - 4 UR - https://cpl.iphy.ac.cn N1 - ER -