We measured the polarization-resolved angular elastic scattering intensity distribution of aggregates composed of primary particles with different shapes and packing densities in the near-backward directions (155°–180°). Specifically, we compare aggregates composed of spherical polystyrene latex spheres, cylinder-like Bacillus subtilis particles, and Arizona road dust, as well as tryptophan particles. We observe clearly differentiable polarization aspect ratios and find that the negative polarization dip is more pronounced in more densely packed aggregates or particles. This work indicates that the polarization aspect ratio in the near-backward direction may be used as a fingerprint to discriminate between aggregates with the same size and overall shape by differences in their constituent particles.
© 2014 Optical Society of America
Original Manuscript: May 16, 2014
Revised Manuscript: June 6, 2014
Manuscript Accepted: June 6, 2014
Published: July 2, 2014
Brandon Redding, Yong-Le Pan, Chuji Wang, and Hui Cao, "Polarization-resolved near-backscattering of airborne aggregates composed of different primary particles," Opt. Lett. 39, 4076-4079 (2014)