论文标题
具有可调式纠缠的宽带光子对的扁平化生成
Flat-optics generation of broadband photon pairs with tunable polarization entanglement
论文作者
论文摘要
“平面光学”的概念正在迅速征服不同的光子学领域，但其在量子光学器件中的实现仍处于起步阶段。尤其是，由于偏振量子乘的编码和控制的简单性，极化纠缠是量子光子学的核心，到目前为止尚未在平坦平台上实现。同时，平坦非线性光学源的松弛相位匹配可以在定制其极化特性方面具有巨大的自由度。在这里，我们利用这种自由来通过自发参数下转换（SPDC）在$ 400 $ nm $ nm的间隙膜中生成具有可调节极化纠缠的光子对。通过更改泵极化，我们将光子对的极化状态从最大纠缠到几乎散开的偏振状态，这在SPDC的单个大量源中是不可能的。极化纠缠与宽带频率谱相结合，导致Ultranarrow（12 fs）Hong-ou-mandel效应，并承诺扩展到过度牙周牙线。
The concept of `flat optics' is quickly conquering different fields of photonics, but its implementation in quantum optics is still at infancy. In particular, polarization entanglement, which is central to quantum photonics due to the simplicity of polarization qubit encoding and control, is so far not realized on flat platforms. Meanwhile, relaxed phase matching of flat nonlinear optical sources enables enormous freedom in tailoring their polarization properties. Here we use this freedom to generate photon pairs with tunable polarization entanglement via spontaneous parametric down-conversion (SPDC) in a $400$ nm GaP film. By changing the pump polarization, we tune the polarization state of photon pairs from maximally entangled to almost disentangled, which is impossible in a single bulk source of SPDC. Polarization entanglement, in combination with the broadband frequency spectrum, results in an ultranarrow (12 fs) Hong-Ou-Mandel effect and promises extensions to hyperentanglement.
