Time-division phase modulated single-photon interference in a Sagnac interferometer
WU Guang, ZHOU Chunyuan & ZENG Heping Key Laboratory of Optical and Magnetic Resonance Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, China Correspondence should be addressed to Zeng Heping (e-mail: hpzeng @phy.ecnu.edu.cn)
We introduce a stable, long-distance single- photon Sagnac interferometer, which has a balanced con-figuration to efficiently compensate phase drift caused by change of the fiber-optic path. By using time-division phase modulation, single-photon interference was realized at 1550 nm in a 5-km-long as well as 27-km-long Sagnac fiber loops, with a fringe visibility higher than 90% and long-term sta-bility. The stable performance of the single-photon interfer-ence indicated that the time-division phase-modulated Sag- nac interferometer might readily lead to practical applica-tions in single-photon routing and quantum cryptography.
【CateGory Index】： O431.2