Plasmonic Networks for Nanoscale Light Control (PINpOiNT)

纳米尺度量子光学是一个很有前途的新领域，旨在对纳米结构光子环境中单个量子发射体发射的单光子进行相干控制和操纵。单个发射体的尺寸比光的波长小得多，因此与辐射的相互作用缓慢而全方位，限制了光子的吸收和发射。当光源被放置在纳米结构的光子材料中时，这些固有的荧光限制可以被克服。多尺度(分形)结构是一类特别有趣的新的光子材料，因为它们导致电磁能量在宽光谱范围内的空间局域化到亚波长区域(10s nm的热点)，这些区域是由不同尺度上的光激发耦合到网络上的。我将研究天然黄金网络和人工设计的网络。我将使用网络理论方法来处理这些结构，这是一种以网络拓扑为中心的统计方法，由链路和节点组成。该方法能够从丰富的微观细节中提取较少的稳健参数来描述复杂系统，从而提供更深入的理解。网络光学特性的研究将集中在探索最稳健的模式特性之一：光态的局域密度。这是光-物质相互作用中的一个关键基本量，因为它提供了对自发光发射(珀塞尔效应)、光吸收和散射的概率的直接测量。我建议通过研究人工等离子体网络中LDOS的统计特性来识别复杂等离子体网络中不同光学模式的出现性质。我计划了解复杂等离子体模的内在特征，并揭示亚波长“热点”、临界局域态和混沌模式特征。这些知识将被用来设计和设计用于局部荧光增强的LDOS，并将该网络用作一种非传统天线来控制单个胶体量子点的荧光、提高其辐射率、增强和操纵其方向性。我将致力于展示等离子体网络结构、它们的光学性质和它们对发光体的影响之间的强烈联系。

Nanoscale quantum optics is a promising new field aimed at coherent control and manipulation of single photons emitted by individual quantum emitters in a nanostructured photonic environment. Single emitters have dimensions much smaller than the wavelength of light, and therefore interact slowly and omni-directionally with radiation, placing limits on photon absorption and emission. These intrinsic fluorescence limits can be overcome when the source is placed in a nanostructured photonic material.Multi-scale (fractal) structures are a new class of particularly interesting photonic materials, since they lead to spatial localisation of the electromagnetic energy into subwavelength areas (hot spots of 10s of nm) over a wide spectral range, which are driven by optical excitations coupled to the network on different scales.Here I propose to investigate collective plasmonic systems, based on plasmon multiple scattering and interference on metallic networks. I will study natural gold networks and artificially designed one. I will approach these structures using a network theory approach, a statistical method centred on the network topology, made of links and nodes. This method has the potentiality of describing the complex system with few robust parameters, extracted from the rich microscopic details, and thus provides much deeper understanding.The study of network optical properties will focus on probing one of the most robust modal properties: the local density of optical states. This is a key fundamental quantity involved in light-matter interaction, as it provides a direct measure for the probability of spontaneous light emission (the Purcell effect), light absorption and scattering. I propose to identify the emergent nature of the different optical modes of complex plasmonic networks by studying the statistics of the LDOS in artificial plasmonic networks. I plan to understand the inner character of the complex plasmonic modes, and to reveal subwavelength "hot-spots", critically localized states and chaotic mode signatures. This knowledge will be exploited to design and engineer the LDOS for local fluorescence enhancement and to exploit the network as an unconventional antenna to control the fluorescence of an individual colloidal quantum dot, enhance its radiation rate, boost and manipulate its directionality.I will aim at demonstrating a strong link between the plasmonic network structures, their optical properties and their effect on a light emitter.