Plasmon resonance in a metal nanowell and raman scattering in microobjects

An analytical theory of plasmon resonance in a metal nanowell deposited on the microobjects under study has been developed. The theory is based on the decomposition of the electromagnetic field into vector spherical harmonics, which occurs during plasmon resonance at the Stokes frequency. The resonant field leads to increased raman scattering (Raman) in microobjects enclosed in a nanowell. The raman emitted by the internal molecules excites a secondary plasmon resonance, which is also decomposed into spherical harmonics. The electromagnetic amplification mechanism of giant raman scattering (GRS) can be investigated qualitatively and quantitatively in this precisely solvable mathematical model. The theoretical results are in qualitative agreement with the results of the GRS experiment in polystyrene spheres partially coated with a silver nanolayer, which serve as a model of typical biological objects.