Application of the discrete dipole approximation to extreme refractive indices: Filtered coupled dipoles revived

We compared three formulations of the discrete dipole approximation (DDA) for simulation of light scattering by particles with refractive indices m = 10 + 10i, 0.1 + i, and 1.6 + 0.01i. These formulations include filtered coupled dipoles (FCD), lattice dispersion relation (LDR) and radiative reaction correction (RRC). We compared number of iterations (proportional to simulation time) and accuracy of final results. We showed that LDR performance for m = 10 + 10i is especially bad, while FCD, which we have implemented in the ADDA computer code, is a good option for all cases studies. Now these extreme refractive indices can be routinely simulated using modern desktop computers.