Light scattering in disordered honeycomb photonic lattices near the Dirac points

TL;DR

This paper investigates how disorder affects light localization in honeycomb photonic lattices, revealing that Anderson localization occurs near Dirac points despite stronger diffraction, with localization characteristics depending on spectral position.

Contribution

It demonstrates that disorder induces Anderson localization in honeycomb lattices near Dirac points, contrasting with normal diffraction at the Brillouin zone center.

Findings

Disorder causes Anderson localization near Dirac points.

Localization width varies with spectral position.

Dirac point excitations show larger output distribution widths.

Abstract

We address Anderson localization in disordered honeycomb photonic lattices and show that the localization process is strongly affected by the spectral position of the input wavepacket within the first Brillouin zone of the lattice. In spite of the fact that in regular lattice the expansion of the beam is much stronger for the excitation near the Dirac points, where light exhibits conical diffraction, than for the excitation at the center of the Brillouin zone, where the beam exhibits normal diffraction, we found that disorder leads to pronounced Anderson localization even around the Dirac points. We found that for the same disorder level the width of the averaged output intensity distribution for excitations around the Dirac points may be substantially larger than that for excitations at the center of the Brillouin zone.