Light Propagation in Composite Two-Dimensional Arrays of Polystyrene Spherical Particles

Light propagation in composite two-dimensional spherical arrays in which mixtures of fluorescent and nonfluorescent polystyrene latex particles (3, 1, 0.5 μm) are packed in a highly dense, highly oriented manner on a solid surface was observed by use of fluorescence microscopy and phase-contrast microscopy. In addition, by means of through-focusing, we were able to determine directly the stacking mode, e.g., face-centered-cubic packing or hexagonal close packing, in up to three layers. The propagation modes can be divided into two types: one inside the particles and the other on the particle surfaces. The contribution of these two modes appears to be dependent upon the relative light frequency.