Plasmon-Exciton Energy Transfer in Metal Nanocavities

技术描述：本项目从实验和理论上研究了金属纳米粒子和激光染料分子在光激发下的能量传递机制。在这种情况下，金属激子(等离子激子)可以与分子激子(激子)相互作用，产生具有足够密度(增益)的激子群，以显示激光。纳米粒子阵列和孤立的纳米粒子都是这些研究中感兴趣的，因为它们都定义了可以使光局部化的光学腔，以提高增益并降低激光的阈值。我们正在研究金属结构附近分子发射体的位置和取向的影响，以确定在微观和纳米水平上哪些光腔最有利于布居反转，以及在宏观水平上确定激光阈值。正在开发的理论模型将电动力学计算与控制激子光物理的速率过程相结合，以模拟实验。这项工作建立在理解一系列纳米等离子体系统中光-物质相互作用的既定实验-理论记录的基础上。它将以前考虑的无源结构扩展到有源和混合等离子体结构，用于激光、增强的增益特性和传感应用。非技术描述：这项工作开发了一种至少在一维上具有亚波长尺寸的新类型的激光器，这将为制造超小型光电子器件提供新的机会。这样的设备可以对高速光通信、高密度信息存储和纳米光刻产生直接和实质性的影响。与这项基础研究相结合的是一个初中/高中和本科生课程开发计划，旨在带来纳米制造和纳米世界中操纵光的前沿科学活动。所有课程都可以在网上获得，也可以通过材料世界模块网站获得。此外，一个关于出版实践和伦理的外展项目旨在发表更好的科学论文，并最终提高科学水平。

Technical Description: This project investigates, experimentally and theoretically, mechanisms of energy transfer between metal nanoparticles and laser dye molecules when both are photoexcited. Under these circumstances, metal excitations (plasmons) can interact with molecular excitations (excitons) to produce exciton populations with sufficient density (gain) to exhibit lasing. Both nanoparticle arrays and isolated nanoparticles are of interest in these studies, as both define optical cavities that can localize light to enhance gain and reduce the threshold for lasing. The effect of position and orientation of molecular emitters near the metal structures are being studied to determine which optical cavities optimize population inversion at the microscopic and nanoscopic levels and the lasing threshold at the macroscopic level. Theoretical models are being developed which couple electrodynamics calculations to the rate processes which govern exciton photophysics to simulate experiment. This work builds on an established experiment-theory track-record on understanding light-matter interactions in a range of nano-plasmonic systems. It extends passive structures considered previously to active and hybrid plasmonic architectures for applications in lasing, enhanced gain properties, and sensing.Non-technical Description: This work develops a new class of lasers having subwavelength dimensions in at least one dimension, which will provide new opportunities for making ultrasmall optoelectronic devices. Such devices can have a direct and substantial impact on high-speed optical communication, high-density information storage, and nanolithography. Coupled with this basic research is a program in middle/high school and undergraduate curriculum development aimed at bringing leading-edge scientific activities in nanofabrication and manipulating light in the nanoworld. All the curricula are available online and through the Materials World Modules site. Also, a program of outreach on publication practices and ethics is aimed at producing better scientific papers and ultimately better science.