Polarized Nonlinear Nanoscopy of Metal Nanostructures
Artikel i vetenskaplig tidskrift, 2017
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 nanoscale. 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 form of polarization resolved microscopy, named polarization nonlinear nanoscopy, which reveals subdiffraction scale vectorial variations of electromagnetic fields, even though the intensity image is diffraction-limited. We show that by exploiting, at a single subdiffraction pixel level, the information gained by the polarization-induced modulation, it is possible to spatially map the vectorial nature of plasmonic nonlinear optical interactions in nanostructures, revealing in particular surface contributions, retardation effects, and anisotropic spatial confinements.
metal
Optics
resonances
Science & Technology - Other Topics
light
optical-properties
plasmonics
nonlinear microscopy
2nd-harmonic generation microscopy
Physics
second harmonic generation
scattering
polariiation
interference
modes
Materials Science
particles
oligomers
gold nanoparticles