Mode mapping of plasmonic stars using TPL microscopy

We investigate the far-field and near-field optical properties of a complex plasmonic system made of gold disks forming a star-like pattern. Scattering spectroscopy first enabled us to monitor the resonant behavior of the structures. Two-photon luminescence (TPL) microscopy was then used to probe the local fields under different orientations of the incident linear polarization. Unlike the scattering spectrum, the TPL distribution over the structure is found to depend drastically on the incident polarization state, in good agreement with a full 3D theoretical simulation of the electric near-field intensity.