论文标题
光子对来源的光谱表征通过经典的频率产生
Spectral characterization of photon-pair sources via classical sum-frequency generation
论文作者
论文摘要
对于光量子信息和测量应用，光子对的光谱特性非常重要。高分辨率光谱测量是光子工程光谱特性的关键技术，使其非常适合各种量子应用。在这里，我们使用自发参数下调（SPDC）产生的频谱测量和优化，利用频率分辨的总和频率产生（SFG），这是SPDC的反向过程。与传统的频率分辨巧合测量值相比，以40 pm的分辨率和> 40 dB的信噪比捕获了1580 nm左右的非线性晶体的联合相匹配光谱，并以40 dB的信号噪声比率捕获。此外，我们的方案适用于共线变性源的表征，而先前证明的差异频率产生（DFG）很困难。我们还说明，观察到的相匹配函数可用于查找最佳泵光谱，以最大程度地提高SPDC光子的光谱不可区分性。我们预计我们的精确光谱特征技术将是对广泛的光学量子应用的表征和调整SPDC源的有用工具
Tailoring spectral properties of photon pairs is of great importance for optical quantum information and measurement applications. High-resolution spectral measurement is a key technique for engineering spectral properties of photons, making them ideal for various quantum applications. Here we demonstrate spectral measurements and optimization of frequency-entangled photon pairs produced via spontaneous parametric downconversion (SPDC), utilizing frequency-resolved sum-frequency generation (SFG), the reverse process of SPDC. A joint phase-matching spectrum of a nonlinear crystal around 1580 nm is captured with a 40 pm resolution and a > 40 dB signal-to-noise ratio, significantly improved compared to traditional frequency-resolved coincidence measurements. Moreover, our scheme is applicable to collinear degenerate sources whose characterization is difficult with previously demonstrated stimulated difference frequency generation (DFG). We also illustrate that the observed phase-matching function is useful for finding an optimal pump spectrum to maximize the spectral indistinguishability of SPDC photons. We expect that our precise spectral characterization technique will be useful tool for characterizing and tailoring SPDC sources for a wide range of optical quantum applications
