Anomalous Light Absorption by Small Particles

TL;DR

This paper reports a novel resonant light absorption phenomenon in small particles that cannot be explained by simple models, showing giant maxima near plasmon resonances due to a balance of damping mechanisms.

Contribution

It introduces a new type of anomalous light absorption in small particles, analyzed using exact Mie solutions, highlighting phenomena beyond dipole approximation.

Findings

Absorption cross-section exhibits giant maxima near plasmon resonances.

Maxima occur when dissipative damping equals radiative damping.

Phenomenon is similar to anomalous scattering previously reported.

Abstract

A new type of resonant light absorption by a small particle (nanocluster) is reported. The problem cannot be described within the commonly used dipole scattering approximation and should be studied with methods based upon the exact Mie solution. It is shown that the absorption cross-section has giant maxima realized at small values of the imaginary part of the complex dielectric permittivity of the particle. The maxima are situated in the vicinity of the plasmon (polariton) resonances and correspond to the regions where the dissipative damping equals the radiative one. The case is similar to the recently introduced anomalous scattering [PRL vol. 97, 263902 (2006)] and exhibits similar peculiarities.