Color Imaging of Aerosol Particles with Backscatter Multiple Wavelength Digital Holography

RAMESH GIRI, Matthew J Berg, Kansas State University

     Abstract Number: 36
     Working Group: Aerosol Physics

Abstract
Course mode aerosol particles with sizes greater than 1 um are common in nature and contribute to various atmospheric changes. To better understand the impact of aerosols on the local and global climate, as well as the global radiation budget, it is critical to understand the way these particles interact with light of various wavelengths. Generally, materials of different composition interact differently across the visible spectrum, yet in situ observations of the material composition of aerosol particles is limited. In previous work, we observe the color images of opaque microparticles fixed to a glass window using backscatter multiple wavelength digital holography [1]. This is extended in this work, to produce color images of aerosol particles without trapping or collecting the particles. A chromaticity analysis is then applied to assess whether particles with different material compositions can be differentiated based on their images’ color content.

References:
[1] R. Giri and M. Berg, “Backscatter multiple wavelength digital holography for color micro-particle imaging,” Appl. Opt. 61, B83-B95 (2022).