Inverse scattering of dispersive stratified structures

TL;DR

This paper investigates the inverse scattering problem for dispersive stratified media, showing conditions for uniqueness and proposing a layer peeling method, with applications to THz technology.

Contribution

It introduces a condition under which the inverse scattering problem becomes unique and provides a layer peeling solution for dispersive media.

Findings

Uniqueness of solution when dispersion is small enough

Layer peeling method effectively retrieves structure

Numerical examples demonstrate practical applicability

Abstract

We consider the inverse scattering problem of retrieving the structural parameters of a stratified medium consisting of dispersive materials, given knowledge of the complex reflection coefficient in a finite frequency range. It is shown that the inverse scattering problem does not have a unique solution in general. When the dispersion is sufficiently small, such that the time-domain Fresnel reflections have durations less than the round-trip time in the layers, the solution is unique and can be found by layer peeling. Numerical examples with dispersive and lossy media are given, demonstrating the usefulness of the method for e.g. THz technology.