Interaction of Light with Ordered Dielectric Spheres: Finite-Difference Time-Domain Analysis

Using the finite-difference time-domain (FDTD) method, interaction between a gaussian wave and ordered dielectric spheres has been numerically calculated for the first time. Real-time images of the spatial distribution of the intensity of light coupling to the dielectric spheres have been presented for gaussian wave and plane-wave incidences. From the images for gaussian wave incidence, we have been able to clearly confirm a remarkable reduction in the light velocity for a flat photon band, i.e., a heavy photon band. It has been pointed out that the situation of the propagation of the gaussian wave is similar to that of the plane-wave. The transmittance T and reflectance R for the normal incidence of light to the ordered spheres have also been evaluated from the FDTD analyses. It has been found that T and R for the gaussian wave can be exactly estimated for the heavy photon band, differing from the plane-wave case.