Flourescence and Raman scattering intensities have been measured for different probe molecules positioned at various defined separation distances from a Ag grating carrying a propagating plasmon surface polariton mode. Thus, the evanescent decay length of such a surface–electromagnetic wave could be mapped out, and was found to agree with theoretical predictions based on a Fresnel formalism.
We report on optical waveguide structures containing a thin liquid crystal (LC) film held between two photochromic command surfaces. The command surfaces consist of three monomolecular layers of a polymer with azobenzene side chains deposited according to the Langmuir-Blodgett-Kuhn technique. When exposed to light of appropriate wavelength, the command surfaces undergo a trans-cis photoisomerization process that induces a reversible change in the liquid crystalline orientation. Such an orientation change of the LC alters the optical properties of the optical waveguide. We present experiments on the dynamics of the LC orientation process.-The transition is shown to be continuous, with the degree of orientation dependent on the ratio of the cis-trans chromophore concentration ratio in the command surface.
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.
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