Max Planck Institute for the Science of Light, Erlangen, Germany.
Phys Rev Lett. 2011 Mar 18;106(11):113901. doi: 10.1103/PhysRevLett.106.113901. Epub 2011 Mar 15.
Optical parametric down-conversion has proven to be a valuable source of nonclassical light. The process is inherently able to produce twin-beam correlations along with individual intensity squeezing of either parametric beam, when pumped far above threshold. Here, we present for the first time the direct observation of intensity squeezing of -1.2 dB of each of the individual parametric beams in parametric down-conversion by use of a high quality whispering-gallery-mode disk resonator. In addition, we observed twin-beam quantum correlations of -2.7 dB with this cavity. Such resonators feature strong optical confinement and offer tunable coupling to an external optical field. This work exemplifies the potential of crystalline whispering-gallery-mode resonators for the generation of quantum light. The simplicity of this device makes the application of quantum light in various fields highly feasible.
光参量下转换已被证明是一种有价值的非经典光源。当泵浦远高于阈值时，该过程固有地能够产生双光束相关以及两个参量光束中任意一个的强度压缩。在这里，我们首次通过使用高质量 whispering-gallery-mode 盘式谐振器直接观察到参量下转换中每个参量光束的强度压缩-1.2 dB。此外，我们还观察到该腔的双光束量子相关-2.7 dB。这种谐振器具有很强的光学限制，并提供可调谐的与外部光场的耦合。这项工作展示了晶体 whispering-gallery-mode 谐振器在产生量子光方面的潜力。该器件的简单性使得量子光在各个领域的应用变得非常可行。
