Sources of broadband quantum correlated photons present a valuable resource for quantum metrology, sensing, and communication. Here, we report the generation of spectrally broadband correlated photons from frequency nondegenerate spontaneous parametric down-conversion in a custom-designed lithium niobate superlattice. The superlattice induces a nonlinear interference between the pump, signal and idler, resulting in an experimentally observed comb-like emission spanning 0.060μm and 1.4μm of spectral bandwidth at 0.647μm and 3.0μm wavelengths, respectively. While this broad mid-infrared bandwidth is attractive to quantum metrology and sensing due to the enablement of fast spectral multiplexing for data acquisition, the comb-like structure, achieved without an input frequency comb, offers targeted frequencies for quantum communication applications. In addition to useful technological applications, our concept offers an interesting analogy between optical diffraction in quantum and classical optics.

宽带量子相关光子源为量子计量、传感和通信提供了宝贵的资源。在这里，我们报告了在定制设计的铌酸锂超晶格中从频率非简并自发参数下转换产生光谱宽带相关光子。超晶格诱导泵，信号和闲频之间的非线性干扰，导致在实验上观察到梳状发射跨越0.060 μ m和1.4 μ在0.647光谱带宽的米μ m和3.0 μm 波长，分别。虽然这种宽广的中红外带宽对量子计量和传感很有吸引力，因为它可以实现数据采集的快速光谱复用，而无需输入频率梳即可实现的梳状结构为量子通信应用提供了目标频率。除了有用的技术应用之外，我们的概念还提供了量子光学和经典光学中的光学衍射之间的有趣类比。