论文标题
从自发参数下转换中未关闭单个光子的二阶相关性和纯度
Second-order correlations and purity of unheralded single photons from spontaneous parametric down-conversion
论文作者
论文摘要
各种量子技术应用需要高生成速率的高纯度单光子。尽管采用了不同的方法来生成这种光子，但自发参数下调（SPDC）的预示了单个光子是最常用的方法。来自预示的单光子源的光子生成速率受到检测器的效率的限制，以记录光子对的复合检测，该光子对低于每个检测器上分别记录的单光子计数。在本文中，我们提出了一个修订的表达式，以计算二阶时间相关函数，对于任何固定时间窗口（bin），$ g^{（2）} $，并报告了SPDC过程中未保密和预示的单光子的纯度的实验表征。有了适当的时间箱作为给定的泵功率，在没有预示的情况下，我们表明，具有$ g^{（2）}（0）= 0 $的单个光子的速率更高，可以以很高的概率生成。
Various quantum technology applications require high-purity single photons with high generation rate. Although different methods are employed to generate such photons, heralded single photons from spontaneous parametric down-conversion (SPDC) is the most commonly used approach. Photon generation rate from the heralded single-photon sources are limited by the efficiency of the detectors to record coincidence detection of the photon pairs which are lower than the single-photon counts recorded separately on each detector. In this paper we present a revised expression to calculate second-order temporal correlation function, $g^{(2)}$ for any fixed time window (bin) and report the experimental characterization of purity of unheralded and heralded single photons from the SPDC process. With an appropriate choice of time bin for a given pump power, without heralding we show that higher rate of single photons with $g^{(2)}(0) = 0$ can be generated with very high probability.
