Pan Feng, Smith Kevin C, Nguyen Hoang L, Knapper Kassandra A, Masiello David J, Goldsmith Randall H
Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706-1322 , United States.
Department of Physics , University of Washington , Seattle , Washington 98195-1560 , United States.
Nano Lett. 2020 Jan 8;20(1):50-58. doi: 10.1021/acs.nanolett.9b02796. Epub 2019 Aug 26.
Control of light-matter interactions is central to numerous advances in quantum communication, information, and sensing. The relative ease with which interactions can be tailored in coupled plasmonic-photonic systems makes them ideal candidates for investigation. To exert control over the interaction between photons and plasmons, it is essential to identify the underlying energy pathways which influence the system's dynamics and determine the critical system parameters, such as the coupling strength and dissipation rates. However, in coupled systems which dissipate energy through multiple competing pathways, simultaneously resolving all parameters from a single experiment is challenging as typical observables such as absorption and scattering each probe only a particular path. In this work, we simultaneously measure both photothermal absorption and two-sided optical transmission in a coupled plasmonic-photonic resonator consisting of plasmonic gold nanorods deposited on a toroidal whispering-gallery-mode optical microresonator. We then present an analytical model which predicts and explains the distinct line shapes observed and quantifies the contribution of each system parameter. By combining this model with experiment, we extract all system parameters with a dynamic range spanning 9 orders of magnitude. Our combined approach provides a full description of plasmonic-photonic energy dynamics in a weakly coupled optical system, a necessary step for future applications that rely on tunability of dissipation and coupling.
光与物质相互作用的控制对于量子通信、信息和传感等众多领域的进展至关重要。在耦合等离子体光子系统中，相互作用能够相对轻松地进行调控，这使得它们成为理想的研究对象。为了对光子与等离子体之间的相互作用施加控制，必须识别影响系统动力学的潜在能量路径，并确定关键的系统参数，如耦合强度和耗散率。然而，在通过多种竞争路径耗散能量的耦合系统中，从单个实验中同时解析所有参数具有挑战性，因为诸如吸收和散射等典型可观测量各自仅探测特定路径。在这项工作中，我们在一个由沉积在环形回音壁模式光学微谐振器上的等离子体金纳米棒组成的耦合等离子体光子谐振器中，同时测量光热吸收和双侧光学透射。然后，我们提出了一个分析模型，该模型预测并解释了所观察到的不同线形，并量化了每个系统参数的贡献。通过将该模型与实验相结合，我们在跨越9个数量级的动态范围内提取了所有系统参数。我们的综合方法全面描述了弱耦合光学系统中的等离子体光子能量动力学，这是未来依赖于耗散和耦合可调性的应用的必要步骤。
