Second harmonic generation by metal core - Dielectric shell spherical nanoparticles: Spatial vs. plasmon resonances

Abstract

An analytical study of the second harmonic generation by metal core - dielectric shell spherical nanoparticles was performed. Dependences of the second harmonic intensity on the dielectric shell thickness were calculated. We demonstrated that the thin coating allows tuning surface plasmon resonance wavelength, whereas in presence of the thick shell spatial Mie resonances occur. Estimated efficiency of these resonances surpasses the impact of the plasmon enhancement in the second harmonic generation. Possibility to combine plasmon (metal) and spatial (dielectric) resonances to achieve even more advantage in the second harmonic generation was shown.