Localization of Light: Dual Symmetry between Absorption and Amplification

TL;DR

This paper reveals that in disordered waveguides, systems with opposite signs of the imaginary dielectric constant exhibit identical localization lengths, showing that absorption and amplification similarly suppress wave transmission despite their physical differences.

Contribution

It uncovers a duality between absorption and amplification in disordered media, demonstrating they have equivalent effects on localization length.

Findings

Dual systems with opposite imaginary parts of dielectric constant share the same localization length.

Absorption and stimulated emission similarly reduce waveguide transmittance.

The study highlights a fundamental symmetry in wave propagation through disordered media.

Abstract

We study the propagation of radiation through a disordered waveguide with a complex dielectric constant $\epsilon$, and show that dual systems, which differ only in the sign of the imaginary part of $\epsilon$, have the same localization length. Paradoxically, absorption and stimulated emission of radiation suppress the transmittance of the waveguide in the same way.