T-matrix approach to calculating circular polarization
of aggregates made of optically active (chiral) materials
and its applications to cometary dust observations
D. W. Mackowski*,1, L. Kolokolova2 and W. Sparks3
- 1 Department of Mechanical Engineering, Auburn University, Auburn, AL, USA.
- 2 Department of Astronomy, University of Maryland, College Park, MD, USA.
- 3 Space Telescope Science Institute, Baltimore, MD, USA.
Optical activity is a typical property of the biological materials where left-handed aminoacids and right-handed carbohydrates dominate (so called homochirality). Observationally, optically active materials reveal themselves through the circular polarization in the light they scatter. Thus, circular polarization produced by the optically active particles can serve as a biomarker. This and other applications stimulated a development of the T-matrix code presented in this paper. It allows us to calculate the scattering matrix, and, specifically circular polarization, of the light scattered by aggregated optically active particles. The code can be used for modeling the light scattering by biological objects (e.g., colonies of bacteria, blood cells) and for interpretation of the circular polarization produced by the cosmic dust that contains (pre)biological organic molecules, e.g., comet dust or planetary aerosols.
- * Corresponding author