Polarization contrast in fluorescence scanning near-field optical microscopy in reflection

Polarization contrast is presented in fluorescence images of a Langmuir-Blodgett monolayer obtained with a scanning near-field optical microscope operated in reflection. A tapered optical fiber is used both to excite and to collect the fluorescence. The lateral resolution in the reflection fluorescence image is estimated at 200 nm. Shear-force detection controls the tip-to- surface distance and simultaneously gives a topographic map. Direct correlation between topography and the fluorescent domain is thus obtained. We show that the fluorescence is polarized along the molecular orientation in the Langmuir- Blodgett monolayer. Thus we demonstrate the study of the polarization direction in the reflection mode.