Finite-difference time-domain solution of light scattering by dielectric particles with large complex refractive indices

The finite-difference time-domain (FDTD) technique is examined for its suit ability for studying light scattering by highly refractive dielectric parti cles. It is found that, for particles with large complex refractive indices , the FDTD solution of Light scattering is sensitive to the numerical treat ments associated with the particle boundaries. Herein, appropriate treatmen ts of the particle boundaries and related electric fields in the frequency domain are introduced and examined to improve the accuracy of the FDTD solu tions. As a result, it is shown that, for a large complex refractive index of 7.1499 + 2.914i for particles with size parameters smaller than 6, the e rrors in extinction and absorption efficiencies fi om the FDTD method are g enerally less than similar to 4%. The errors in the scattering phase functi on are less than similar to 5%. We conclude that the present FDTD scheme wi th appropriate boundary treatments can provide a reliable solution for ligh t scattering by nonspherical particles with large complex refractive indice s. (C) 2000 Optical Society of America OCIS codes: 010.1290, 010.1310, 010. 3920, 290.5850, 290.1090, 280.1100.