| abstract: |
We have investigated the optical properties of solid grains by means of aerosol technology. So far, laboratory measurements on real particle ensembles have not been able to provide exact band profiles for a direct comparison due to the use of an embedding medium (KBr, CsI) in the sample preparation, which changes the band profile substantially by the influence of its electromagnetic polarization.We have adopted aerosol technology for laboratory measurements of extinction spectra avoiding the influence of electromagnetic interaction with solid embedding media. We have created an environment that small-sized particles (< 1 micron) are freely suspended in a gas cell (N2-gas), which has13.6 cm in diameter and 55.7 cm in total length. While the particles are freely flying the cell, the extinction spectra of these suspended particles are successfully measured. We have used electron-microscopic investigation (SEM & TEM) of the grains to associate morphological (size, shape, agglomeration) influences on the measured profile as well. As a result of that, it has been revealed that peak positions, bandwidth, and strength of extinction spectra are strongly influenced by particle morphology. Results obtained by aerosol spectroscopy and experimental methods will be reported.
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