Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength
Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength
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DOI：
10.1364/oe.22.011498
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发表时间：
2014-05-19
期刊：
影响因子：
3.8
通讯作者：
Sasaki, Masahide
中科院分区：
文献类型：
--
作者：
Jin, Rui-Bo;Shimizu, Ryosuke;Sasaki, Masahide
我们在Sagnac干涉仪配置下展示了周期性极化KTiOPO4 （PPKTP）晶体在电信波长下产生的脉冲偏振纠缠光子。由于满足群速度匹配（GVM）条件，在800 nm波长附近光子的本征光谱纯度远高于原方案。Sagnac干涉仪和gmm - ppktp晶体的结合使我们的纠缠源紧凑、稳定、高度纠缠、光谱纯净且超亮。两个超导纳米线单光子探测器（SNSPDs）在暗计数小于1 kcps时检测效率分别为70%和68%。我们分别获得了垂直杆psi(-)>和垂直杆psi(+)>的0.981 +/- 0.0002和0.980 +/- 0.001。GVM-PPKTP-Sagnac方案直接适用于电信波长的量子通信实验，特别是自由空间的量子通信实验。(C) 2014年美国光学学会
We demonstrate pulsed polarization-entangled photons generated from a periodically poled KTiOPO4 (PPKTP) crystal in a Sagnac interferometer configuration at telecom wavelength. Since the group-velocity-matching (GVM) condition is satisfied, the intrinsic spectral purity of the photons is much higher than in the previous scheme at around 800 nm wavelength. The combination of a Sagnac interferometer and the GVM-PPKTP crystal makes our entangled source compact, stable, highly entangled, spectrally pure and ultra-bright. The photons were detected by two superconducting nanowire single photon detectors (SNSPDs) with detection efficiencies of 70% and 68% at dark counts of less than 1 kcps. We achieved fidelities of 0.981 +/- 0.0002 for vertical bar psi(-)> and 0.980 +/- 0.001 for vertical bar psi(+)> respectively. This GVM-PPKTP-Sagnac scheme is directly applicable to quantum communication experiments at telecom wavelength, especially in free space. (C) 2014 Optical Society of America