Spatial intensity correlation functions are obtained from near-field scanning optical microscope measurements of semicontinuous metal-dielectric films. The concentration of metal particles on a dielectric surface is varied over a wide range to control the scattering strength. At low and high metal coverages where scattering is weak, the intensity correlation functions exhibit oscillations in the direction of incident light due to excitation of propagating surface waves. In the intermediate regime of metal concentration, the oscillatory behavior is replaced by a monotonic decay as a result of strong scattering and anomalous absorption. Significant differences in the near-field intensity correlations between metallic and dielectric random systems are demonstrated.
K. Seal et al., "Near-Field Intensity Correlations in Semicontinuous Metal-Dielectric Films," Physical Review Letters, American Physical Society (APS), Jan 2005.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevLett.94.226101
United States. Army Research Office
National Science Foundation (U.S.)
Keywords and Phrases
Dielectric Thin Films; Discontinuous Metallic Thin Films; Near-Field Scanning Optical Microscopy; Surface Plasmons
Article - Journal
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