“…Although the vector KKR for the periodic system of cylindrical rods can perform the numerical computation most in a short time (Ohtaka et al, 1998), in this research, the periodic fast multipole method with higher flexibility (periodic FMM) is employed. In general, when the Maxwell equations are numerically solved in a large-scale system, the fast multipole method, which is the boundary element method to which multipole expansion is applied, is well used, where, in the boundary element method, the differential equations, i.e., the Maxwell equations, are transformed into an integral equation by means of a tensor Green function.…”