Theoretical analysis of the density of states and phase times: Applicationto resonant electromagnetic modes in finite superlattices - art. no. 035312

In this paper, we derive exact relations between the density of states and the reflection and transmission phase times of a scalar mode in a finite la mellar composite system sandwiched between two different homogeneous semi-i nfinite media. We illustrate the results of this analysis by analytical and numerical solutions for a substrate-buffer layer-finite superlattice-air s ystem. We give the density of states and phase times as a function of the f requency omega and the wave vector k(parallel to) parallel to the interface s. Specific applications of our results are given for electromagnetic modes of a SiO2 buffer layer/finite GaAs-AlAs superlattice sandwiched between a GaAs substrate and air.