Direct measurements of magnetic and electric optical responses from silicon nanoparticles

We report on our experimental and numerical studies of optically-induced magnetic and electric dipole resonances of spherical silicon nanoparticles. We combine polarization-resolved dark-field spectroscopy and near-field scanning optical microscopy and demonstrate experimentally that electromagnetic fields scattered by nanoparticles exhibit strong sensitivity to the probing beam polarization both in far- and near-field regions. We suggest that our complex experimental approach can be employed as a powerful tool for analysing nanoscale photonic systems possessing both electric and magnetic dipole responses.