Microsphere Assisted Super-resolution Optical Imaging of Plasmonic Interaction between Gold Nanoparticles.

ABSTRACT: Conventional far-field microscopy cannot directly resolve the sub-diffraction spatial distribution of localized surface plasmons in metal nanostructures. Using BaTiO3 microspheres as far-field superlenses by collecting the near-field signal, we can map the origin of enhanced two-photon photoluminescence signal from the gap region of gold nanosphere dimers and gold nanorod dimers beyond the diffraction limit, on a conventional far-field microscope. As the angle ? between dimer's structural axis and laser polarisation changes, photoluminescence intensity varies with a cos4? function, which agrees quantitatively with numerical simulations. An optical resolution of about ?/7 (?: two-photon luminescence central wavelength) is demonstrated at dimer's gap region.

SUBMITTER: Hou B 

PROVIDER: S-EPMC5653755 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature