Finite-difference time-domain (FDTD) method is known as a popular way to perform computational electrodynamics. This method was

originally devised to analyze electromagnetic field distribution

around an antenna. Recently, its outstanding usefulness has mani-

fested itself with the development of nanotechnology, because near

and far electromagnetic fields resulting from the interaction of light

with complicated microstructure are easily simulated, which are

often difficult to obtain in actual measurements. Although a lot of

excellent papers and books describing its principle, algorithm and

applications have been published so far, herewewill briefly describe

its principle of calculation for the reader’s convenience. For this

purpose, we will follow an excellent book written by Uno, where

the comprehensive description of the FDTD method is given [Uno