Numerical Modeling of Spoof Localized Surface Plasmons

Kazuhiro FUJITA  

C - Abstracts of IEICE TRANSACTIONS on Electronics (Japanese Edition)   Vol.J99-C   No.5   pp.250-257
Publication Date: 2016/05/01
Online ISSN: 1881-0217
Type of Manuscript: INVITED PAPER
spoof plasmon,  localized surface plasmon,  surface wave,  finite-difference time-domain method,  method of moments,  

Full Text(in Japanese): FreePDF(1.1MB)

The use of surface plasmons (SPs) has been mainly discussed in visible and near-infrared frequency range so far. By contrast, there are spoof surface plasmons (spoof SPs) as a concept for extending the SPs into low frequencies such as microwave and terahertz (THz) bands. The spoof SPs is a kind of electromagnetic surface waves strongly confined near metallic surfaces with subwavelength microstructures. A wide range of applications have been anticipated due to the capability of controlling its physical features by the geometries of the surface. Recently, the concept of SP was applied to structured closing surfaces and the existence of a low frequency phenomenon mimicking the localized surface plasmons was reported. This is called as spoof localized surface plasmons (spoof LSPs). So far, numerical modeling of the spoof LSPs is not studied in detail. In this paper, we focus on the method of moments and the finite-difference time- domain method as electromagnetic numerical methods with different features, and compare both through analyzing the conventional electromagnetic structures supporting spoof LSP modes at a THz band. In numerical examples we evaluate numerical accuracy and computational time for the two, and finally reveal numerical modeling which is suitable for the spoof LSPs.