Nested Equivalent Source Approximation for the Simulation of Surface Enhanced Raman Scattering

A multiregion nested equivalence source approximation (NESA) is presented for the analysis of surface enhance raman scattering (SERS) of the plasmonic nano particles above a substrate. Simulation of SERS is typical near field evaluations with the requirement of high precision. With the NESA, the asymptotic computational costs of the algorithm are compatible with the state-of-the-art factorizations, namely, linear and quasi-linear [O(N) and O(N log N)] for moderate and large scale problems, respectively. Numerical examples validate the accuracy and favorable computational cost of NESA when applied to SERS simulations.