Abstract
Amorphous structures have attracted increasing research attention due to their interesting characteristics, such as isotropic structures and noniridescent colors. In this work, studies are presented based on finite-difference time-domain (FDTD) method for analyzing the optical characteristics of amorphous structures. In the first part, we present photonic amorphous structures with different characteristic lengths and analyze their structural and topological properties. We present the numerical analysis to characterize the density of state (DOS) of amorphous structures based on different structural parameters. The corresponding spatial Fourier spectra of amorphous structures are calculated to examine the characteristic length, and the photonic band gap properties will be discussed in association with the characteristic length. These results are crucial for the design of new optical materials display devices base on dielectric amorphous photonic structures. In the second part, we investigate the effective optical properties of nanoporous materials with amorphous structures. If the pore sizes are much smaller than the wavelength of visible light, the nanoporous structure can be considered as a homogeneous medium with the same effective refractive index. By changing the properties of effective media, the optical properties of films can be controlled.