Rukhlenko Ivan D, Handapangoda Dayan, Premaratne Malin, Fedorov Anatoly V, Baranov Alexander V, Jagadish Chennupati
Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Victoria 3800, Australia.
Opt Express. 2009 Sep 28;17(20):17570-81. doi: 10.1364/OE.17.017570.
In this paper, we theoretically analyze the emission of guided polaritons accompanying spontaneous recombination in a semiconductor quantum dot coupled to metallic nanowire. This study is aimed to shed light on the interaction between optically excited quantum emitters and metallic nanowaveguides beyond the validity of dipole approximation. To the best of our knowledge, this is the first time the geometry of quantum emitter and spatial inhomogeneity of the electric field constituting the fundamental polariton mode are fully taken into account. Even though we performed the analysis for disk-like quantum dot, all the conclusions are quite general and remain valid for any emitter with nanometer dimensions. Particularly, we found that the strong inhomogeneity of the electric field near the nanowire surface results in a variety of dipole-forbidden transitions in the quantum dot energy s ctra. It was also unambiguously shown that there is a certain nanowire radius that gives maximum emission efficiency into the fundamental polariton mode. Since the dipole approximation breaks for nanowires with small radii and relatively big nanoemitters, the above features need to be considered in the engineering of plasmonic devices for nanophotonic networks.
在本文中，我们从理论上分析了与耦合到金属纳米线的半导体量子点中的自发复合相关的导模极化激元发射。本研究旨在阐明光激发量子发射体与金属纳米波导之间的相互作用，这超出了偶极近似的有效性范围。据我们所知，这是首次充分考虑构成基本极化激元模式的量子发射体的几何形状和电场的空间不均匀性。尽管我们对盘状量子点进行了分析，但所有结论都相当普遍，对任何纳米尺寸的发射体都仍然有效。特别地，我们发现纳米线表面附近电场的强烈不均匀性导致量子点能谱中出现各种偶极禁戒跃迁。还明确表明，存在某个纳米线半径，它能使进入基本极化激元模式的发射效率达到最大值。由于对于小半径纳米线和相对较大的纳米发射体，偶极近似不再适用，因此在用于纳米光子网络的等离子体器件工程中需要考虑上述特性。
