Suppression of light propagation in a medium made of randomly arranged dielectric spheres

TL;DR

This paper demonstrates that densely packed dielectric spheres can significantly suppress light propagation at specific resonant frequencies, leading to potential applications in fabricating omnidirectional photonic bandgap materials.

Contribution

It introduces a rigorous diffraction theory to analyze light suppression in random dielectric sphere arrangements and shows the feasibility of creating omnidirectional photonic gaps with simple fabrication.

Findings

Local density of states decreases exponentially at Mie resonances.

Suppression occurs in spectral domains where single spheres resonate.

Self-sustaining random core-shell sphere arrangements exhibit similar suppression characteristics.

Abstract

Light propagation in a medium made of densely packed dielectric spheres is investigated by using a rigorous diffraction theory. It is shown that a substantial suppression of the local density of states occurs in spectral domains where the single constituents exhibit Mie resonances. The local density of states decreases exponentially at the pertinent frequencies with a linearly increasing spatial extension of the aggregated spheres. It is shown that a self-sustaining random arrangement of core-shell spheres shows the same fundamental characteristics. Such approach offers a path towards easy to fabricate photonic materials with omnidirectional gaps that may find use in various applications.