Quasi Normal Modes description of transmission properties for Photonic Band Gap structures

TL;DR

This paper applies the Quasi Normal Modes approach to analyze transmission in 1D Photonic Band Gap structures, introducing a novel method for calculating QNM norms and exploring the dynamical nature of mode density.

Contribution

It introduces a new method for calculating QNM norms in 1D PBG structures and discusses the dynamical variability of mode density under different boundary and initial conditions.

Findings

QNM approach effectively describes transmission properties.

A new simple method for QNM norm calculation is proposed.

Mode density is shown to be a dynamical variable.

Abstract

In this paper, we use the 'Quasi Normal Modes' (QNM) approach for discussing the transmission properties of double-side opened optical cavities: in particular, this approach is specified for one dimensional (1D) 'Photonic Band Gap' (PBG) structures. Moreover, we conjecture that the density of the modes (DOM) is a dynamical variable which has the flexibility of varying with respect to the boundary conditions as well as the initial conditions; in fact, the e.m. field generated by two monochromatic counter-propagating pump waves leads to interference effects inside a quarter-wave (QW) symmetric 1D-PBG structure. Finally, here, for the first time, a large number of theoretical assumptions on QNM metrics for an open cavity, never discussed in literature, are proved, and a simple and direct method to calculate the QNM norm for a 1D-PBG structure is reported.