Search

Based on nanoscale photopolymerization triggered by the dipolar surface plasmon mode, we developed a light-emitting gold nanoparticle/Eosin Y-doped polymer hybrid nanostructure. Due to the anisotropic spatial distribution of the dipolar surface plasmon mode during photopolymerization, this nano-emitter is anisotropic in both geometry and emission. The trapped dye molecules in the hybrid nanostructure display fluorescence intensity that is dependent upon the polarization of the incident excitation light. This nano-emitter further allows the photo-selection of fluorescence configuration (i.e., molecule concentration and refractive index of active medium) by controlling the incident polarization. [ABSTRACT FROM AUTHOR]

Summary We report an apertureless near-field optical study on nanostructured objects formed by J-aggregates adsorbed on silver (Ag) nanoparticles. Near-field images reveal that the enhanced near-field from the dressed particle's (DP) resonantly excited plasmon oscillation is efficiently absorbed by the J-aggregates. The sensitivity of the near-field images recorded at the harmonics of the probe vibration frequency suggests that the DP is releasing part of the absorbed energy radiatively upon interaction with the probe. The role of the probe in providing this new radiative relaxation channel is further confirmed as fluorescence from the J-aggregates on the particle is detected on the particle location only. We based the interpretation of our results on the near-field optical response from a bare Ag particle excited at the plasmon resonance as well as on far-field emission and transient absorption experiments. [ABSTRACT FROM AUTHOR]

Apertureless scanning near-field optical microscopy is a method for obtaining subwavelength optical images of nanostructures. However, great care must be taken to avoid artifactual images. We report on one artifact related to the error signal in cantilever vibration amplitude when operating in tapping mode atomic force microscopy. The artifact is described experimentally and modeled by electromagnetic calculations based on the finite element method. We report specific steps to identify and avoid this artifact with experimental results on gold nanostructures. It is suggested that future apertureless scanning near-field optical microscopy studies verify that optical image does not correlate with error signal. [ABSTRACT FROM AUTHOR]