Comparison of electromagnetic field solvers for the 3D analysis of plasmonic nano antennas

TL;DR

This paper compares different electromagnetic field solvers for 3D analysis of plasmonic nano antennas, highlighting their strengths and limitations in handling complex geometries and material properties at optical frequencies.

Contribution

It provides a comprehensive comparison of time domain and frequency domain solvers, including commercial and semi-analytic methods, for accurate plasmonic nano antenna analysis.

Findings

Frequency domain solvers generally offer higher accuracy for plasmonic structures.

Time domain solvers face challenges with narrow gaps and material dispersion.

Semi-analytic MMP code serves as a high-accuracy reference.

Abstract

Plasmonic nano antennas are highly attractive at optical frequencies due to their strong resonances - even when their size is smaller than the wavelength - and because of their potential of extreme field enhancement. Such antennas may be applied for sensing of biological nano particles as well as for single molecule detection. Because of considerable material losses and strong dispersion of metals at optical frequencies, the numerical analysis of plasmonic antennas is very demanding. An additional difficulty is caused when very narrow gaps between nano particles are utilized for increasing the field enhancement. In this paper we discuss the main difficulties of time domain solvers, namely FDTD and FVTD and we compare various frequency domain solvers, namely the commercial FEM packages JCMsuite, Comsol, HFSS,and Microwave Studio with the semi-analytic MMP code that may be used as a reference due to its fast convergence and high accuracy.