结构参数对领结型纳米孔等离子体光镊共振效应的影响  

Influences of Structural Parameters on Resonant Effect of Bowtie Nanohole Plasmonic Tweezer

作　　者：李畅畅 王艳红[1,2] 武京治[1,2] Li Changchang;Wang Yanhong;Wu Jingzhi(School of Information and Communication Engineering,North University of China,Taiyuan 030051,China;Academy for Advanced Interdisciplinary Research,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学信息与通信工程学院,太原030051 [2]中北大学前沿交叉科学研究院,太原030051

出　　处：《微纳电子技术》2024年第5期74-78,共5页Micronanoelectronic Technology

基　　金：国防科技创新特区(02-ZT-008)。

摘　　要：等离子体光镊可以将光场能量限制在纳米级的体积内,从而产生较大的梯度力对粒子进行捕获和操纵。使用时域有限差分(FDTD)方法对金膜上的领结型纳米孔进行数值分析,结果表明,在波长为400~2 000 nm范围内存在两种模式的共振,分别为Fabry-Pérot共振和等离子体共振。Fabry-Pérot共振对金膜厚度比较敏感,随着金膜厚度增加,共振峰发生90 nm的红移;而等离子体共振峰随着孔径和孔间距的增加向波长更大的方向偏移;通过模拟粒子捕获,发现与其他材料的粒子相比,金粒子会导致等离子体共振峰发生更大的偏移,且随着粒子从结构外运动至结构底部,共振峰会持续发生红移。本研究对实际应用中纳米结构的制备具有参考价值,且在单分子操纵、生物传感等方面具有重要意义。The plasmonic tweezer can limit the light field energy to a nano-scale volume,resulting in a large gradient force to capture and manipulate the particle.The bowtie nanoholes on the gold film were numerically analyzed by the finite difference time domain(FDTD)method.The results show that there are two types of resonances in the wavelength range of 400-2000 nm,which are Fabry-Pérot resonance and plasmonic resonance,respectively.The Fabry-Pérot resonance is sensitive to the thickness of the gold film,and the resonance peak has a red shift of 90 nm with the increase of the thickness of the gold film.The plasmonic resonance peak shifts to a larger wavelength with the increase of the aperture diameter and pitch of holes.By simulating the particle capture,it is found that gold particles cause a larger shift in the plasmonic resonance peak than particles of other materials,and when the particles move from the outside to the bottom of the structure,the resonance peak will continue to red shift.This study has reference value for the preparation of nanostructures in practical applications,and has important significance in the aspects of single molecule manipulation,biosensing and so on.

关 键 词：等离子体光镊 梯度力 Fabry-Pérot共振 等离子体共振 红移 

分 类 号：O433[机械工程—光学工程]