單光子源研究為量子光學的核心要素之一，而單光子源的產生效率及訊號提升一直是科學家追求的目標。本論文便是著重於產生高純度的單光子源，我們運用基於電磁波引發透明的自發四波混頻系統，在冷原子系統中產生一對具有時間關聯性的雙光子對，並且可利用格勞伯(Roy J. Glauber)提出的二階關聯性函數(second-order correlation function)解析兩顆光子之間的關聯性。在我們的觀察下，在光學密度（OD）為10，驅動光拉比頻率（Rabi frequency）1Γ、耦合光拉比頻率4Γ的情況，其符合計數之訊號背景比高達61，產生率為2.3×10^5每秒；而若改變驅動光拉比頻率為2$Gamma$，其訊號背景比約為25，產生率可達到9.1×10^5每秒，顯現其具有高度的量子特性及良好的產生效率。

Single-photon source is an essential building block in quantum information sciences. In this thesis, we demonstrate the generation of the high purity, correlated single-photon sources through electromagnetically-induced-transparency (EIT)-based spontaneous four-wave mixing (SFWM) in cold atomic ensemble. In experiment, time correlations between the generated Stokes and anti-Stokes photons are measured using Glauber second-order correlation function. Under an optical depth (OD) of 10 , we observe the photon pair generation of around 9.1×10^5. Moreover, high purity paired photon sources with a signal- to-background ratio (SBR) of 61 are obtained by further decreasing the driving Rabi frequency. All the experimental results are in good agreement with the theoretical predictions.

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