Hentschel Michael, Hübel Hannes, Poppe Andreas, Zeilinger Anton
Institute for Quantum Optics and Quantum Information - IQOQI, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria.
Opt Express. 2009 Dec 7;17(25):23153-9. doi: 10.1364/OE.17.023153.
We demonstrate a compact and stable source of polarization-entangled pairs of photons, one at 810 nm wavelength for high detection efficiency and the other at 1550 nm for long-distance fiber communication networks. Due to a novel Sagnac-based design of the interferometer no active stabilization is needed. Using only one 30 mm ppKTP bulk crystal the source produces photons with a spectral brightness of 1.13 x 10(6) pairs/s/mW/THz with an entanglement fidelity of 98.2%. Both photons are single-mode fiber coupled and ready to be used in quantum key distribution (QKD) or transmission of photonic quantum states over large distances.
我们展示了一种紧凑且稳定的偏振纠缠光子对源，一个光子的波长为810纳米，用于实现高探测效率，另一个光子的波长为1550纳米，用于长距离光纤通信网络。由于采用了基于新型萨尼亚克干涉仪的设计，无需主动稳定化。该源仅使用一块30毫米的周期极化磷酸钛氧钾（ppKTP）块状晶体，就能产生光谱亮度为1.13×10⁶对/秒/毫瓦/太赫兹的光子，纠缠保真度为98.2%。两个光子均耦合到单模光纤中，可随时用于量子密钥分发（QKD）或长距离光子量子态传输。
