基于源偶极子的扫描近场光学显微镜的数值模拟  

Numerical simulation of scanning nearfield optical microscopy based on the source dipole model

作　　者：吴昌林 王长[1,2] 曹俊诚 WU Chang-Lin;WANG Chang;CAO Jun-Cheng(Key Laboratory of Terahertz Solid-State Technology,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海微系统与信息技术研究所太赫兹固态技术重点实验室,上海200050 [2]中国科学院大学材料科学与光电工程中心,北京100049

出　　处：《红外与毫米波学报》2023年第5期643-651,共9页Journal of Infrared and Millimeter Waves

基　　金：Supported by the National Natural Science Foundation of China(61927813,61975225);Science and Technology Commission of Shanghai Municipality(21DZ1101102)。

摘　　要：红外和太赫兹范围内的扫描近场光学显微镜能够突破衍射极限,实现更小的空间分辨率,在纳米尺度结构的光学特性分析检测方面具有重要应用。为了进一步理解探针与样品的相互作用,对探针近场的分析和数值描述是必不可少的。基于真实的探针形状的解析模型,结合数值模拟的开发了源偶极子模型(SDM),能够直接获得近场检测信息,提高计算效率。基于模拟结果,解释了天线效应、尖端半径影响和电荷量的影响,并将SDM模型结果与全波仿真(FWS)结果进行了比较。为进一步理解近场光学显微镜中的针尖-样品结提供了新的视角。Scanning near-field optical microscopy in the infrared and terahertz ranges has attracted much interest in studying objects far below the diffraction limit,particularly in the detection of optical properties of structures on the nanoscale.To further understand the tip-sample interaction,analytical and numerical description of the near fields from the probe is essential.Here,we established and analytically solved a more realistic analytical model based on the real probe shape.Based on the combination of the analytical model and numerical simulation to develop the source dipole model(SDM),a comparison with the new method to full-wave simulation(FWS)re⁃sults was performed.In simulations combined with the theoretical model,the detection information is obtained di⁃rectly,and the computational efficiency is improved.Based on simulation results,the antenna effect,tip apex ra⁃dius influence,and the influence of charge amount are explained.This paper provides a new perspective to fur⁃ther understand the tip-sample junction in optical nanoscopy.

关 键 词：太赫兹 近场显微技术 数值模拟 偶极模型 光学性质 

分 类 号：O472.3[理学—半导体物理]