Resonance-domain effects in second-harmonic generation from metal nanostructures

Summary form only given. We study second-harmonic generation from arrays of anisotropic metal nanoparticles (metamolecules) as a function of their mutual arrangement. The overall second-harmonic response of such samples cannot be simply described by the orientational average of the individual metamolecules. Instead, the response can vary by more than an order of magnitude for the same average orientational distribution depending on the detailed ordering of the metamolecules in the array. The results are explained by diffractive long-range coupling between the metamolecules.