非相干变频转换实现室温下红外单光子源
Incoherent photon conversion to generate infrared single photons at room temperature
-
摘要: 纳米金刚石中的NV-center(Nitrogen-Vacancy center)是目前室温下具有高发射率和稳定性的可见光波段单光子源,而如何实现及优化红外单光子源则是未来实现量子信息和量子通信应用的一大挑战.介绍了一种近期提出的实现红外单光子源的新型机制.该方法以金刚石中的NV-center作为可见光波段的单光子源,利用非相干变频转换实现室温下近红外波段稳定、无闪烁的单光子源.具体的实施方案为在中空芯光子晶体光纤中选择性地填充含有量子点的溶液,以可见光波段的单光子源作为激励源,选择合适的量子点即可得到红外波段的单光子源.中空芯光子晶体光纤保证了较高的单光子吸收效率以及荧光收集效率.该方案的实施在理论上可以达到26%的转换效率,而初步的实验得到了0.1%的转换效率.进一步分析了一些影响转换效率的因素,并提出了一些解决方案.Abstract: At present, there exist a number of on-demand single photon sources with high emission rates and stability even at room temperature such as NV centers in diamonds. However, further improvement of infrared single photon sources is a major challenge for future implementations of quantum information and quantum communication applications. A conceptually novel method for the generation of infrared single photons was concerned which was recently presented. The presented method was applied to realize a stable, non-blinking, room temperature infrared single photon source by converting visible single photons from a defect center in diamond to the near infrared. A hollow core photonic crystal fiber selectively filled with a solution of quantum dots was used to achieve a single photon absorption probability of near unity and a very high re-collection efficiency of Stokes-shifted fluorescence. For this presented implementation, a theoretical conversion efficiency is estimated to be 26%. And a conversion efficiency of 0.1% is achieved in a first prove of principle experiment. To improve this efficiency, the conversion process was taken insights and some solutions were put forward.