A Fluorescence Scanning Near-Field Optical Microscope operated in reflection is presented. A pulled optical fiber is used both as an emitter for the exciting light and a collector for the generated fluorescence. The advantage of this set-up is the use of the fiber tip as an emitter and a collector. The sample is locally illuminated and no extra optical elements are needed for the detection. We will describe the shear force set-up which is used to control the tip to surface distance. Direct correlation between force map and optical signal is thus possible. Fluorescence images have been obtained on Langmuir-Blodgett films where we estimate the resolution at 200 nm. Moreover the anisotropic property of the monolayer allows polarization contrast measurements. Thus, we show true optical contrast due to fluorescence and polarization is applicable to this configuration. Artifacts in LB films shear force image are discussed. Shear force approach curves obtained on glass and polymer domains are presented to explain the chemical origin of the phenomenon.
|Name||Proceedings of SPIE|
|Conference||SPIE's International Conference on Optical Science, Engineering, and Instrumentation 1995|
|Period||9/07/95 → 14/07/95|