Exploring properties of few molecules in tightly-confined plasmonic nanocavities

本项目旨在研究磁场、温度梯度和红外光对捕获光的金属部件之间亚纳米等离子激元间隙中分子的光学性质的影响。在直径为60-100 nm的金纳米粒子的镜面下，自组装单分子膜中的100个分子经历了一个高度受限的光场。它们的复杂折射率控制着在暗场散射中看到的光学模式，以及在表面增强拉曼光谱(SERS)中看到的信号。在这个项目中，你将探索一些可以改变这些分子的折射率的控制参数，以便快速调整光学模式，并潜在地提供低能光学开关。同时，这应该会发展对光-物质耦合在纳米尺度上的基本理解，在环境环境的许多方面都是未知的。第一个控制参数将是施加到系统的磁场。第二个有待开发的领域是跨单分子层的温度梯度的影响。第三个要探索的领域是在NPOM内部的分子上使用可调红外激光(波长为5-11微米)。所有这些都对在低能量IT设备和基础科学中使用分子等离子激元具有重要意义。

This project aims to study the influence of magnetic fields, thermal gradients, and infra-red light on the optical properties of molecules in the sub-nm plasmon gaps between metallic components that trap light. Underneath a 60-100nm diameter Au nanoparticle on mirror, the 100 molecules in a self-assembled monolayer experience a highly confined optical field. Their complex refractive index controls the optical modes seen in dark field scattering, as well as the signatures seen in surface-enhanced Raman spectroscopy (SERS).In this project you will explore some of the control parameters that can modify the refractive index of these molecules, in order to tune the optical modes rapidly, and potentially to deliver low energy optical switching. At the same time, this should develop fundamental understandings of light-matter coupling on the nanoscale in ambient environments in many aspects are unknown. The first control parameter will be the magnetic field applied to the system. The second area to develop is the effect of thermal gradients across single molecule layers. A third area to explore is the use of tuneable infrared lasers (5-11um wavelength) on the molecules inside the NPoM. These all have implications for using molecular plasmonics in low energy IT devices as well as fundamental science.