US Scientists have successfully used second harmonic generation (SHG) measurements to probe the complicated plasmon resonances arising from inter-particle interactions within nanoparticle networks.
Kenneth Knappenberger Jr. and Manabendra Chandra from Florida State University performed systematic polarization-resolved single-particle SHG measurements on solid gold nanosphere dimers. In addition, continuous polarization variation (CPV) experiments were used to obtain single particle non-linear optical data. They were able to demonstrate the superiority of their technique over measurements that rely exclusively on linearly polarized light to study structure-specific plasmonics.
A large SHG depolarization ratio was measured when the two nanoparticles forming a dimer were in close vicinity of each other. CPV spectra of single dimers revealed large inter-dimer variations, which can only be described by including magnetic-dipolar interactions.
Their work represents an important step towards a predictive understanding of the optical properties of nanostructured materials.
Read this HOT PCCP article today:
Nanoparticle surface electromagnetic fields studied by single-particle nonlinear optical spectroscopy
Manabendra Chandra and Kenneth L. Knappenberger
DOI: 10.1039/C2CP43271D, Paper