ABSTRACT
Photonic crystals (PC) are artificial multidimensional periodic structures whose period is of the order of optical wavelength. Fundamentally, they are based on a concept extended from conventional diffraction gratings and have a unique analogy to solid state crystals. This enables one to use solid state physics theory for the analysis of PCs. For example, one can calculate photonic bands, photonic bandgaps (PBG), impurity, defect and surface states, etc., for any PCs. The structure that consists of airholes in a high index slab is called PC slab. It is widely used for various device applications, because it confines light by the PBG effect in the slab plane, and by the total internal reflection in the out-of-plane direction. The most common use of the Finite-Difference Time-Domain method is the simulation of lightwaves in a finite size structure. It gives fundamental characteristics such as electromagnetic field distributions, transmission spectrum, time response, and so on.
