REFLECTION-SCANNING NEAR-FIELD OPTICAL MICROSCOPY AND SPECTROSCOPY OFOPAQUE SAMPLES

Opaque samples are imaged by Scanning Near-field Optical Microscopy (S NOM) in reflection mode: A quartz glass fiber tip is used both to illu minate the sample and to collect light locally reflected from or emitt ed by the surface. The collected light is coupled out by a 2 x 2 fiber coupler and fed into a grating spectrometer for spectral analysis at each sampled point. The tip-sample distance is controlled by a shear-f orce feedback system. The simultaneous measurement of topography and o ptical signals allows an assessment of imaging artifacts, notably topo graphy-induced intensity changes. It is demonstrated that an optical r eflectance contrast not induced by topographic interference can be fou nd on suitable samples. Local spectral analysis is shown in images of a photoluminescent layer.