Photon density of states for a dielectric superlattice

Abstract

Many useful and interesting optical applications of thin films make use of multilayer stacks of films, or a superlattice. To evaporate multiple layers while maintaining control over both refractive index and individual layer thickness has become a matured technology today. In this work, light scattering in a dielectric superlattice is investigated. The polarization characteristics including the transverse electric (TE) and transverse magnetic (TM) modes are considered in our simulation model. A transfer matrix approach is employed to discretize the dielectric function profile of the dielectric superlattice and the transmission functions are calculated by matching the boundary conditions at each interfaces. In order to solve the dispersion relation, the corresponding band structures are obtained by solving the eigenvalue equations with proper periodic boundary conditions as following the Bloch theorem. The equifrequency surfaces in wave-vector space are employed to facilitate the calculation of the photon density of states (PDOS). The PDOS of the superlattice for the TE and TM modes are obtained, respectively.