Di Domenico Giuseppe, Pearl Shaul, Karnieli Aviv, Trajtenberg-Mills Sivan, Juwiler Irit, Eisenberg Hagai S, Arie Ady
Opt Express. 2022 Jun 6;30(12):21535-21543. doi: 10.1364/OE.451641.
Optical N00N states are N-photon path entangled states with important applications in quantum metrology. However, their use was limited till now owing to the difficulties of generating them in an efficient and robust manner. Here we propose and experimentally demonstrate two new simple, compact and robust schemes to generate path entangled N00N states with N = 2 that emerge directly from the nonlinear interaction. The first scheme is based on shaping the pump beam, and the second scheme is based on modulating the nonlinear coefficient of the crystal. These new methods exhibit high coincidence count rates for the detection of a N00N state, reaching record value of 2 × 10 coincidences per second. We observe super-resolution by measuring the second order correlation on the generated N = 2 state in an interferometric setup, showing the distinct fringe periodicity at half of the optical wavelength. Our findings may pave the way towards scalable and efficient sources for super-resolved quantum metrology applications and for the generation of bright squeezed vacuum states.
光学N00N态是N光子路径纠缠态，在量子计量学中有重要应用。然而，由于难以高效且稳健地产生它们，其应用至今仍受到限制。在此，我们提出并通过实验证明了两种新的简单、紧凑且稳健的方案，用于产生N = 2的路径纠缠N00N态，该态直接源于非线性相互作用。第一种方案基于对泵浦光束进行整形，第二种方案基于调制晶体的非线性系数。这些新方法在检测N00N态时展现出高符合计数率，达到每秒2×10次符合的记录值。我们通过在干涉测量装置中测量所产生的N = 2态的二阶关联来观测超分辨率，在光波长的一半处显示出明显的条纹周期性。我们的研究结果可能为超分辨量子计量应用以及产生明亮压缩真空态的可扩展且高效的光源铺平道路。
