Fluorescence resonant energy transfer in the optical near field

We develop a versatile theoretical framework for the study of fluorescence resonant energy transfer (FRET, or Forster transfer) in complex environments, under arbitrary illumination, including optical near fields. By combining the field-susceptibility formalism with the optical Bloch equations method, we derive general equations for the computation of the energy transfer between pairs of donor-acceptor molecules excited by optical near fields and placed in a complex geometry. This approach allows accounting for both the variations of the molecular population rates and the influence of the environment. Several examples illustrate the ability of the technique to analyze recent FRET experiments performed in the optical near field

Polarization-dependent fluorescence from an anisotropic gold/polymer hybrid nano-emitter

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. (C) 2014 AIP Publishing LLC