论文标题
单金属纳米棒的光学特性：分析模型
Optical properties of single metal nanorods: An analytical model
论文作者
论文摘要
众所周知，可以用雷利近似或严格的MIE理论来描述球形金属颗粒的光学特性。但是对于单个金属纳米棒，仍然没有理论捕捉基本共振和散射特征的理论仍然没有。在这项研究中，考虑到纵向不均匀的传导电流和表面电荷，为金属纳米棒开发了一个分析模型。通过从纳米棒的动力学和电磁能推导的电路参数，已经提出了一种与仿真相符的公式，这是针对基本纵向模式的共振波长的。此外，通过引入对电路理论的辐射电阻，偶极矩，灭绝谱和纳米棒的近场增强已被分析并在数值上得出。结果对于理解金属纳米棒的光学特性很重要，并提供了设计光散射和吸收的指南。
It is well known that the optical properties of spherical metal particles can be described with the Rayleigh approximation or rigorous Mie theory. But for the single metallic nanorods, a theory well capturing the fundamental resonance and scattering features is still absent. In this study, an analytical model is developed for the metallic nanorod, considering the longitudinally non-uniform conduction current and surface charges. With the circuit parameters deduced from the kinetic and electromagnetic energy of the nanorod, a formula which agrees well with the simulations has been suggested for the resonance wavelength of the fundamental longitudinal mode. Moreover, by introducing the radiative resistance to the circuit theory, the dipole moment, extinction spectrum, and near-field enhancement of the nanorod have been derived analytically and confirmed numerically. The results are important for understanding the optical properties of the metallic nanorods and provide a guideline for designing the light scattering and absorption.
