Dispersive surface plasmon microscopy for the characterization of ultrathin organic films

We report on experiments, applying a novel microscopy method for ultrathin-film characterization which uses the dispersion properties of plasmon surface polaritons (PSP) as a contrast giving mechanism. In contrast to prior methods, we apply white light instead of a laser for resonant PSP excitation. For a given incident angle and an area of given thickness, a narrow spectral band of the incident light is at resonance for PSP excitation. Therefore, we obtain images with areas of different thickness appearing in different color. As an example, we present microscopic images taken from a thin Cu-phthalocyanine film, evaporated onto solid support through a mask. In addition, we compare the obtained images to theoretical considerations on the contrast mechanism. (C) 1996 American Institute of Physics.