G225 Reflectance of close-packed structures of silica micro-spheres

The reflection property of the close-packed structure of silica micro-spheres consists of specular and diffuse component. The characteristic of close-packed structure appears in specular component. On the other hand, the particulate systems exhibit scattering property. In this paper, the specular and diffuse reflection properties of the close-packed structure assembled with 3μm silica micro-spheres are investigated. The experimental setup is developed for the measurement of spectral reflectance. The measurement is carried out by using an FT-IR spectrometer. The specular component of spectral reflectance is compared with previous experimental result measured by microscopic FT-IR spectrometer. The diffuse reflection is observed blow 5μm in wavelength.