Density of modes and tunneling times in finite one-dimensional photonic crystals: A comprehensive analysis

Abstract

We present a unified treatment of density of modes and tunneling times in finite, one-dimensional photonic crystals. We exploit connections and differences between the various approaches used to calculate the density of modes, which include the Green function, the Wigner phase time, and the electromagnetic energy density, and conclude that the Green function is always the correct path to the true density of modes. We also find that for an arbitrary structure the density of modes can always be found as the ratio between the power emitted by a source located inside the structure and the power emitted by the same source in free space, regardless of absorption or dispersion. © 2004 The American Physical Society.