论文标题
等离子体 - 脱离核心壳颗粒的光学非线性：热的作用
Optical Non-linearities in Plasmon-Exciton Core-Shell Particles: the Role of Heat
论文作者
论文摘要
等离子体和激子之间的强耦合会导致具有各种潜在应用领域的新混合极化状态。尽管对等离子体系统进行了大量研究，但它们的瞬时行为尚未完全理解。除了在光激发之后，除了第一个飞秒之后的Rabi振荡外，耦合系统在Picsecond Time量表上显示出有趣的非线性特征。在这里，我们最终证明了这些特征的来源是粒子内部产生的热量。到目前为止，该假设仅基于现象学论据。我们通过记录血浆核心 - 壳纳米颗粒的瞬时光谱来研究热量的作用，并在极化共振上激发。我们提出了仅通过假设颗粒内电子气体的初始温度升高来精确地重新创建测量结果的分析模拟。这些仿真结合了描述未偶联的等离子体颗粒与最近发表的静态光谱模型的既定策略。这些模拟对于各种激发能力是一致的，确认颗粒的加热确实是瞬态信号变化的根源。
Strong coupling between plasmons and excitons gives rise to new hybrid polariton states with various fields of potential applications. Despite a plethora of research on plasmon--exciton systems, their transient behaviour is not yet fully understood. Besides Rabi oscillations in the first femtoseconds after an optical excitation, coupled systems show interesting non-linear features on the picosecond time scale. Here, we conclusively show that the source of these features is heat that is generated inside the particles. Until now, this hypothesis was only based on phenomenological arguments. We investigate the role of heat by recording transient spectra of plasmon--exciton core--shell nanoparticles with excitation off the polariton resonance. We present analytical simulations that precisely recreate the measurements solely by assuming an initial temperature rise of the electron gas inside the particles. The simulations combine established strategies for describing uncoupled plasmonic particles with a recently published model for static spectra. The simulations are consistent for various excitation powers confirming that indeed heating of the particles is the root of the changes in the transient signals.
