Elastic back-scattering patterns via particle surface roughness and orientation from single trapped airborne aerosol particles

DOI: 
10.1016/j.jqsrt.2016.09.018
Publication date: 
01/01/2017
Main author: 
Fu R.
IAA authors: 
Muñoz, O.
Authors: 
Fu R., Wang C., Muñoz O., Videen G., Santarpia J.L., Pan Y.-L.
Journal: 
Journal of Quantitative Spectroscopy and Radiative Transfer
Refereed: 
Yes
Publication type: 
Article
Volume: 
187
Pages: 
224-231
Number: 
Abstract: 
We demonstrate a method for simultaneously measuring the back-scattering patterns and images of single laser-trapped airborne aerosol particles. This arrangement allows us to observe how the back-scattering patterns change with particle size, shape, surface roughness, orientation, etc. The recoded scattering patterns cover the angular ranges of θ=167.7–180° (including at 180° exactly) and ϕ=0–360° in spherical coordinates. The patterns show that the width of the average speckle intensity islands or rings is inversely proportional to particle size and how the shape of these intensity rings or islands also depends on the surface roughness. For an irregularly shaped particle with substantial roughness, the back-scattering patterns are formed with speckle intensity islands, the size and orientations of these islands depend more on the overall particle size and orientation, but have less relevance to the fine alteration of the surface structure and shapes. The back-scattering intensity at 180° is very sensitive to the particle parameters. It can change from a maximum to a minimum with a change of 0.1% in particle size or refractive index. The method has potential use in characterizing airborne aerosol particles, and may be used to provide back-scattering information for LIDAR applications. © 2016
Database: 
SCOPUS
ADS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991704681&doi=10.1016%2fj.jqsrt.2016.09.018&partnerID=40&md5=e5f92118777323e436be23a5d0c62f8a
ADS Bibcode: 
2017JQSRT.187..224F
Keywords: 
Elastic backscattering pattern; Image monitoring; Laser trapping; Single airborne particle; Surface roughness