Frequency domain analysis for optical propagation using Yee lattice

We developed a frequency domain simulator using the Yee lattice, which is compatible with the FDTD method. An S-matrix approach for quantum physics was applied to this simulator for the first time, as far as we know. It can then obtain arbitrary S-matrix elements where the S-matrix always satisfies unitarity within numerical error less than 10^-8 for double precision format.