Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, Bau 24, Erlangen 91058, Germany.
Nat Commun. 2013;4:1818. doi: 10.1038/ncomms2838.
The generation of high-quality single-photon states with controllable narrow spectral bandwidths and central frequencies is key to facilitate efficient coupling of any atomic system to non-classical light fields. Such an interaction is essential in numerous experiments for fundamental science and applications in quantum communication and information processing, as well as in quantum metrology. Here we implement a fully tunable, narrow-band and efficient single-photon source based on a whispering gallery mode resonator. Our disk-shaped, monolithic and intrinsically stable resonator is made of lithium niobate and supports a cavity-assisted spontaneous parametric down-conversion process. The generated photon pairs are emitted into two highly tunable resonator modes. We verify wavelength tuning over 100 nm of both modes with controllable bandwidth between 7.2 and 13 MHz. Heralding of single photons yields anti-bunching with g(2)(0)<0.2.
生成具有可控窄谱带宽和中心频率的高质量单光子态是实现任何原子系统与非经典光场有效耦合的关键。这种相互作用在基础科学实验以及量子通信和信息处理以及量子计量学等领域的应用中至关重要。在这里，我们实现了一种完全可调谐、窄带且高效的基于回音壁模式谐振器的单光子源。我们的盘状、单片且固有稳定的谐振器由铌酸锂制成，支持腔辅助的自发参量下转换过程。产生的光子对被发射到两个高度可调谐的谐振器模式中。我们验证了两个模式的波长调谐超过 100nm，带宽可在 7.2 和 13MHz 之间控制。单光子的信号产生了具有 g(2)(0)<0.2 的反聚束。
