Quantum Engineering Technology Labs, H. H. Wills Physics Laboratory and Department of Electrical &Electronic Engineering, University of Bristol, BS8 1FD, UK.
Hewlett-Packard Laboratories, 1501 Page Mill Rd., Palo Alto, CA 94304-1126, USA.
Sci Rep. 2016 Dec 20;6:38908. doi: 10.1038/srep38908.
We generate photon pairs in a-Si:H microrings using a CW pump, and find the Kerr coefficient of a-Si:H to be 3.73 ± 0.25 × 10m/W. By measuring the Q factor with coupled power we find that the loss in the a-Si:H micro-rings scales linearly with power, and therefore cannot originate from two photon absorption. Theoretically comparing a-Si:H and c-Si micro-ring pair sources, we show that the high Kerr coefficient of this sample of a-Si:H is best utilized for microrings with Q factors below 10, but that for higher Q factor devices the photon pair rate is greatly suppressed due to the first order loss.
我们使用连续波泵浦在非晶硅微环中产生光子对，并发现非晶硅的克尔系数为 3.73±0.25×10m/W。通过测量耦合功率的 Q 因子，我们发现非晶硅微环中的损耗与功率呈线性关系，因此不可能源于双光子吸收。通过理论比较非晶硅和单晶硅微环对光源，我们表明，这种非晶硅样品的高克尔系数最适合用于 Q 因子低于 10 的微环，但对于更高 Q 因子的器件，由于一阶损耗，光子对速率会大大抑制。
