Configurational resonances phenomena in optical scattering spectroscopy of nano-objects

The light scattering from a nano-sized object formed by two or three dipole atoms (polarizable components) is studied in detail using a microscopic approach. The atoms are considered to be linear Lorenz oscillators interacting via the electromagnetic field only. For simple configuration of nano-object, the self-consistent electromagnetic problem is solved analytically. It is shown that the near-field interaction between the dipole atoms can give rise to a dramatic modification of the polarizing characteristics of atoms and the total polarizability of nano-object. We point out the existence of a number of resonance peaks in the frequency dependences. The shift of resonance peaks from the position of the resonances corresponding to the isolated atoms depends mainly on the interatomic distances and can significantly exceed the natural linewidth. Generally, the resonance characteristics of atoms depend on various system parameters such as the atomic polarizabilities (i.e. the eigenfrequencies), the number of atoms, and the interatomic distances. The scattered light intensity detected in wave zone is shown to depend essentially on the configuration of nano-object, the light frequency, polarization, and direction of external wave.