- Author
-
Markel, V. A.
- Title
- Coupled Dipole Method for Computing the Optical Properties of Fractal Aggregates of Silver Particles. BFRL Fire Research Seminar. VHS Video.
- Coporate
- University of Georgia, Athens
- Report
-
Video
December 8, 1998
- Keywords
-
aggregates
|
optical properties
- Abstract
- The seminar will focus on numerical and experimental results concerning optical properties of fractal aggregates of many little silver particles with typical sizes of 10-30nm. Resonance electromagnetic interactions between the particles lead to a number of interesting optical phenomena such as inhomogeneous broadening of the absorption spectra, localization and enhancement of local electromagnetic fields and nonlinear optical responses, and wavelenght- and polarization-selective spectral hole burning. Recent near-field optical spectroscopy experiments allowed direct imaging of areas of localization and enhancement of EM fields ("hot spots"). Numerical calculations are in good qualitative agreement with the experimental observations and they provide physical insights into the phenomenon. The talk will emphasize numerical approaches including the use and validity of the "dipole approximation" for large fractal structures, which, in general, has a much wider range of actuality than just for silver aggregates, including possible applications to fractal smoke and similar problems.