Wedge Waveguides and Resonators for Quantum Plasmonics.
Wedge Waveguides and Resonators for Quantum Plasmonics.
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DOI：
10.1021/acs.nanolett.5b03051
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发表时间：
2015-09-09
期刊：
影响因子：
10.8
通讯作者：
Norris DJ
中科院分区：
文献类型：
--
作者：
Kress SJ;Antolinez FV;Richner P;Jayanti SV;Kim DK;Prins F;Riedinger A;Fischer MP;Meyer S;McPeak KM;Poulikakos D;Norris DJ
等离子体结构可以提供有助于增强光-物质相互作用的深亚波电磁场。然而，由于这些局域模式也是耗散的，人们一直在寻找在场限制和损耗之间提供最佳折衷的结构。金属楔形波导最初被认为是一种理想的候选材料，但由于到目前为止其实验性能一直受到限制，因此在很大程度上被放弃了。我们将最先进的金属楔子与集成反射器和精确放置的胶体量子点(精确到单发射器级别)结合在一起，展示了性能接近理论极限的量子等离子体波导和谐振器。通过利用楔形等离子体激元传输(19μm，真空波长，λvac，630 nm)、高效反射器(93%)和有效耦合(估计为70%)到高发射率(∼90%)量子点的近10倍的改进，我们获得了品质因数接近200(3.3 nm线宽)的可见光波长的银等离子体谐振器。由于我们的结构在裸露的单模波导-谐振器几何结构中提供了低至∼0.004λVA3的模式体积，因此它们在增强光与物质的相互作用方面比传统的光子微腔和局域等离子体谐振器都具有优势。我们的结果证实了楔形体在制造等离子体器件和研究相干量子等离子体效应方面的前景，例如长距离等离子体介导的纠缠和强等离子体-物质耦合。
Plasmonic structures can provide deep-subwavelength electromagnetic fields that are useful for enhancing light–matter interactions. However, because these localized modes are also dissipative, structures that offer the best compromise between field confinement and loss have been sought. Metallic wedge waveguides were initially identified as an ideal candidate but have been largely abandoned because to date their experimental performance has been limited. We combine state-of-the-art metallic wedges with integrated reflectors and precisely placed colloidal quantum dots (down to the single-emitter level) and demonstrate quantum-plasmonic waveguides and resonators with performance approaching theoretical limits. By exploiting a nearly 10-fold improvement in wedge-plasmon propagation (19 μm at a vacuum wavelength, λvac, of 630 nm), efficient reflectors (93%), and effective coupling (estimated to be >70%) to highly emissive (∼90%) quantum dots, we obtain Ag plasmonic resonators at visible wavelengths with quality factors approaching 200 (3.3 nm line widths). As our structures offer modal volumes down to ∼0.004λvac3 in an exposed single-mode waveguide–resonator geometry, they provide advantages over both traditional photonic microcavities and localized-plasmonic resonators for enhancing light–matter interactions. Our results confirm the promise of wedges for creating plasmonic devices and for studying coherent quantum-plasmonic effects such as long-distance plasmon-mediated entanglement and strong plasmon–matter coupling.