Near-field scanning optical microscopy: Single channel imaging of selected gold nanoparticles through two photon induced photoluminescence

Mohammad Kamal Hossain, Masahiro Kitajima, Kohei Imura, Hiromi Okamoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)


Near-field scanning optical microscopy (NSOM) is known to be a technique of choice to investigate nanometric materials and their properties beyond far-field diffraction limit resulting high spatial, spectral and temporal resolution. Here in this report, a state of art facility, aperture-NSOM was used to probe single nanoparticle, dimer, trimer and small nanoaggregate of gold nanoparticles. Shear force topography and two photon induced photoluminescence (TPI-PL) images captured simultaneously by the system facilitated to clarify the correlation between the local geometry and the emitted photon of TPI-PL. Small gold aggregates including trimer showed strong optical confinement of TPI-PL with reference to that of single gold nanoparticles. It was also evident that the interparticle gap does have a great influence in localized electromagnetic (EM) field mediated optical confinement of TPI-PL. Such observations were also supported by finite different time domain (FDTD) analysis keeping the simulation parameter nearly identical to that of experiment. FDTD simulation demonstrated that incident excitation parallel to the interparticle axis induces strong near-field distribution at the interstitials whereas out of plane excitation modifies such confinement depending on the nanometric geometry of the nanoaggregates. Such an observation is indispensable to understand the localized EM field-mediated optical confinement in surfaceenhanced spectroscopy.

Original languageEnglish
Title of host publicationNanomaterials
Subtitle of host publicationScience, Technology and Applications
PublisherTrans Tech Publications Ltd
Number of pages5
ISBN (Print)9783038350989
Publication statusPublished - 2014

Publication series

NameAdvanced Materials Research
ISSN (Print)1022-6680
ISSN (Electronic)1662-8985


  • FDTD
  • Gold
  • Localized EM
  • Nano-aggregate
  • Nanoparticles
  • Near-field
  • TPI-PL

ASJC Scopus subject areas

  • Engineering(all)


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