Finite-difference time-domain solution of light scattering by dielectric particles with a perfectly matched layer absorbing boundary condition

摘要

A three-dimensional finite-difference time-domain (FDTD) program has been developed to provide a numerical solution for light scattering by nonspherical dielectric particles. The perfectly matched layer (PML) absorbing boundary condition (ABC) is used to truncate the computational domain As a result of using the PML ABC; the present FDTD program requires much less computer memory and CPU time than those that use traditional truncation techniques. For spheres with particle-size parameters u large as 40, the extinction and-absorption efficiencies from the present FDTD program match the MIS results closely, with differences of less than~1%. The difference in the scattering phase function is typically smaller than ,~5%. The FDTD program has also been checked by use of the exact solution for light scattering by use of the exact solution for light scattering by a pair of spheres in contact. Finally, applications of the PML FDTD to hexagonal particles and to spheres aggregated into tetrahedral structures are presented. #1999 Optical Society of America. OCIS codes: 010.1290, 010.1310, 010.3920, 290.5850, 290,1090, 280.1100.