Dyshlyuk Anton V, Proskurin Alexey, Bogdanov Andrey A, Vitrik Oleg B
Institute of Automation and Control Processes (IACP) FEB RAS, Far Eastern Federal University (FEFU) and Vladivostok State University of Economics and Service (VSUES), 690041 Vladivostok, Russia.
School of Physics and Engineering, ITMO University, 197101 St. Petersburg, Russia.
Nanomaterials (Basel). 2021 Nov 2;11(11):2937. doi: 10.3390/nano11112937.
Since surface plasmon polaritons (SPPs) are surface waves, they cannot be excited by an incident plane wave, because free-space photons do not possess a sufficient in-plane momentum. Phase matching between the incident light and SPP can be achieved using a high-refractive-index prism, grating, or nanoantennas. In this work, we found an expression for the amplitude of SPP excited by an arbitrary 3D current distribution placed near a metal interface. The developed method is based on the well-known technique used in waveguide theory that enables finding the amplitudes of waveguide modes excited by the external currents. It reduces the SPP excitation problem to the summation of the set of emitters. As a particular example, we considered a spherical dipole nanoantenna on a metal substrate illuminated by a normally incident plane wave. The analytical calculations were in good agreement with the full-wave numerical simulations.
由于表面等离激元极化激元（SPP）是表面波，它们不能被入射平面波激发，因为自由空间光子不具备足够的面内动量。使用高折射率棱镜、光栅或纳米天线可以实现入射光与SPP之间的相位匹配。在这项工作中，我们找到了由置于金属界面附近的任意三维电流分布激发的SPP振幅的表达式。所开发的方法基于波导理论中使用的著名技术，该技术能够找到由外部电流激发的波导模式的振幅。它将SPP激发问题简化为一组发射器的求和。作为一个具体例子，我们考虑了由垂直入射平面波照射的金属基底上的球形偶极子纳米天线。解析计算结果与全波数值模拟结果吻合良好。
