Polarized nonlinear nanoscopy of metal nanostructures

Naveen Kumar Balla , Carolina Rendon , Luong Mai Hoang , Pawel Karpinski , Esteban Bermudez Urena (1) , Sophie Brasselet (2)

1 ICFO - Institut de Ciencies Fotoniques [Castelldefels]
2 MOSAIC - MOSAIC

Nonlinear signals from metal nanostructures are known to be highly polarization-dependent, due to the intrinsic vectorial nature of nonlinear optical coupling. Nonlinear optical polarization responses contain important information on the near-field properties of nanostructures; however they remain complex to monitor and to model at the nano-scale. Polarization resolved nonlinear optical microscopy can potentially address this question, however the recorded signals are generally averaged over the diffraction-limited size of a few hundreds of nanometers, thus missing the spatial specificity of the nanostructure's optical response. Here we present a method of polarized nanoscopy that exploits sub-diffraction resolution information down to a few tens of nanometer. Even though the resulting image is diffraction-limited, the information gained by polarization-induced modulation provides a higher level of selectivity that is directly related to vectorial optical responses at a scale below the diffraction limit. We show that polarized nonlinear nanoscopy permits to spatially map the vectorial nature of plasmonic nonlinear optical interactions in nanostructures.

Domaines: Optique / photonique

Naveen Kumar Balla, Carolina Rendon, Luong Mai Hoang, Pawel Karpinski, Esteban Bermudez Urena, et al.. Polarized nonlinear nanoscopy of metal nanostructures. ACS photonics, 2017, 7, pp.292-301. ⟨10.1021/acsphotonics.6b00635⟩. ⟨hal-01537953⟩