Study of light-matter interaction in the near field of nanostructured objects by fluorescence super-resolved microscopy. ; Étude de l'interaction rayonnement-matière en champ proche de nanostructures par microscopie de fluorescence super-résolue.

In this thesiswe study the interaction of lightwith the environment at the nanoscale. Fluorescent emitters are ideal candidates to probe this interaction because their emission properties strongly depend on the surrounding environment. The emitters’ decay rate is directly linked to the local density of electromagnetic states, which is therefore the most appropriate parameter to quantify the interactions with the environment.This thesis is organized into two parts. The first one concerns the development and the implementation of a wide-field super-resolved lifetime microscopy technique at the single molecule level. This technique is based on the simultaneous measurement of single-molecules’ decay rate with a linear matrix of single photon detectors and of their position with an amplified camera. Experimental results obtained in the near-field of a silver nanowire are analyzedand compared with numerical simulations. Such comparison provides the evidence of the plasmonicmirage effect induced by the presence of the nanowire.Moreover we show that, by making a selection on the measured decay rate and on the size of the corresponding point spread function, it is possible to deduce the orientation of the molecular dipole moments and their real position on the sample. The second part of this thesis is focused on the study of nanostructured optical waveguides. We report on the measurement, performed with a fluorescent scanning near-field microscope, of the field generated around a tapered silica nanofiber by a collimated beam perpendicular to it. The results are in very good agreement with numerical simulations based on Mie theory. We also study a dielectric/plasmonic hybrid waveguide. A plasmonic nanoantenna fabricated on top of a dielectric optical waveguide enhances the coupling of the emission of a fluorescent emitter to the guided mode. The design and fabrication of an optimized device are achieved thanks to numerical simulations. An experimental approach is also proposed to characterize this device. ; Au cours de ...