MLFMA for large-scale nanoplasmonics modeling

The advance in nanoplasmonics is oftentimes limited by the availability of electromagnetic analysis tools capable of addressing large, complex realistic systems that encompass multiple wavelength scales. The present work shows that surface integral equation (SIE) method of moments (MoM) formulations, expedited via the multilevel fast multipole algorithm (MLFMA), can effectively model the interaction of light with large nanoplasmonic assemblies. We illustrate this by simulating realistic gold-nanostar dimers and analyzing the application of their plasmons for sensing, thanks to spatial confinement and field enhancement. We further simulate surface-enhanced Raman scattering (SERS) intensity maps from a thin film containing ~1500 of these nanostars. The proposed methodology raises the bar of full-wave simulations in the field of nanoplasmonics to an unprecedented level of complexity.