As the use of optical waveguides expands, it would be desirable to have an
explicit three-dimensional simulation method to analyze characteristics and
develop new devices. One such method is the finite-difference time-domain
(FDTD) method. The FDTD method requires a relatively high sampling density
per wavelength, making simulation over distances of several wavelengths dif
ficult. Several techniques are described to make such a simulation possible
with limited computer resources. Among them is a moving problem space, whi
ch holds the pulse in the middle and moves the background medium past the p
ulse. Simultaneously, Fourier and wavelet analyses are used to characterize
the pulse.