Optical antennas attract ever increasing interest due to their ability to manipulate light – matter interaction at the nanoscale. By concentrating electromagnetic fields to dimensions not accessible by free-space propagating waves they create highly localized fields that have found application in near-field microscopy, nanooptical device technologies and higher efficiency solar cells. We exploit the intrinsic nonlinear properties of materials at nanoscale to excite localized fields at wavelength different than the excitation wavelengths. This non-linear optical response can be used for characterization of local hot – spots of metallic nanoparticles , near-field imaging  or dark-field microscopy .
© 2011 Optical Society of AmericaPDF Article