论文标题
使金纳米颗粒在超材料等离激元镊中的自我引起的反作用捕获
Enabling self-induced back-action trapping of gold nanoparticles in metamaterial plasmonic tweezers
论文作者
论文摘要
对具有低功率的高效纳米颗粒捕获的追求导致光学镊子技术从传统的自由空间配置转变为先进的等离子镊子系统。但是，即使对于等离子镊子，捕获小于10 nm的纳米颗粒仍然是一个挑战。适当的纳米腔设计和激发导致了自我诱导的反作用（SIBA）效应，从而提高了激光功率，从而增强了捕获刚度。在这项工作中，我们研究了超材料镊子的SIBA效应及其与展览的Fano共鸣的协同作用。我们展示了20 nm金颗粒的稳定捕获，可用于抗谐振和抗谐振的条件，实验性陷阱刚度高达4.18 fn/（nm*mw/$ $ $ $ m $^2 $，激发强度的非常低的激发强度，约1 mw/$ $ $ m $ m $ m $ m $^2 $。陷阱刚度，这是这些系统的独特特征。
The pursuit for efficient nanoparticle trapping with low powers has led to optical tweezers technology moving from the conventional free-space configuration to advanced plasmonic tweezers systems. However, trapping nanoparticles smaller than 10 nm still remains a challenge even for plasmonic tweezers. Proper nanocavity design and excitation has given rise to the self-induced back-action (SIBA) effect offering enhanced trapping stiffness with decreased laser power. In this work, we investigate the SIBA effect in metamaterial tweezers and its synergy with the exhibited Fano resonance. We demonstrate stable trapping of 20 nm gold particles for on-resonant and off-resonant conditions with experimental trap stiffnesses as high as 4.18 fN/(nm*mW/$μ$m$^2$ and very low excitation intensity of about 1 mW/$μ$m$^2$. Simulations reveal the existence of two different groups of hotspots per unit cell of the metamaterial array. The two hotspots exhibit tunable trap stiffnesses and this is a unique feature of these systems. It can allow for sorting of particles and biological molecules based on their size, shape, and refractive index.
