The third-order non-linearity of silicon gives rise to a spontaneous four-wave mixing process in which correlated photon pairs are generated. Sources based on this effect can be used for quantum computation and cryptography, and can in principle be integrated with standard CMOS fabrication technology and components. However, one of the major challenges is the on-chip demultiplexing of the photons, and in particular the filtering of the pump power, which is many orders of magnitude larger than that of the signal and idler photons. Here, we propose a photonic crystal coupled-cavity system designed so that the coupling of the pump mode to the output channel is strictly zero due to symmetry. We further analyze this effect in presence of fabrication disorder and find that, even then, a pump suppression of close to 40 dB can be achieved in state-of-the art systems. Due to the small mode volumes and high quality factors, our system is also expected to have a generation efficiency much higher than in standard micro-ring systems. Those two considerations make a strong case for the integration of our proposed design in future on-chip quantum technologies.

翻译：硅的三阶非线性产生自发四波混合过程,产生相配光子。基于此效应的来源可用于量子计算和加密,原则上可以与标准的 CMOS 制造技术和组件结合。然而,一个重大挑战是光子在芯上脱钩,特别是泵功率的过滤,其规模比信号和闲置光子大得多。在这里,我们提出一个光学晶体结合孔系统,其设计是,由于对称性,泵模式与输出通道的连接完全为零。我们进一步分析这种效果,发现即使这样,在最新艺术系统中也可以达到近40 dB 的压压压。由于模式量小和高品质因素,我们的系统还可望产生比标准的微环系统要高得多的发电效率。这两个因素有力地证明,将我们拟议的设计纳入未来的芯压量技术。