Light Scattering and Absorption by Particles

Scattering and absorption of electromagnetic radiation such as light by particles are used in many subjects as they can provide information on the size, shape, number, and dynamics of the particles or objects. This is important in fields as diverse as physical chemistry, materials science, nanotechnology, microbiology, astronomy, atmospheric sciences and radar. Accordingly, studying how particles scatter and absorb light has been a subject of interest for many years.

A coherent description and understanding of light scattering, especially by irregularly shaped particles, requires an approach different than previous works. This is not purely an academic concern, most aerosol mass in the atmosphere, including entrained mineral dust, volcanic ash, and soot consists of particles with irregular shapes and the way they scatter and absorb light has implications for many climate models. This book develops a new approach that employs the magnitude of the scattering wave vector, q, with dimensions of inverse length, as the fundamental independent variable. That is, scattering is viewed in reciprocal or Q-space. Q-space analysis has been used extensively in small angle x-ray and neutron scattering where the "refractive indices" are relatively weak. On the other hand, the author in his research studies has applied Q-space analysis to refractive particles of all sorts to find new functionalities and parameters that lead to a universal description of light scattering by particles of all sizes, shapes and refractive indices.

This book provides a thorough overview of how particles of any size or shape scatter and absorb light and introduces the Q-space analysis of light scattering for researchers in physics and related applied sciences. It applies to scattering from spheres of arbitrary size and complex refractive index, fractal aggregates and irregularly shaped particles such as dusts. Q-space analysis provides a simple and comprehensive description of scattering that can compare the similarities and differences of the scattering by different types of particles. It also leads to physical interpretation of the scattering mechanisms and critically it yields additional information and descriptions that may not be readily found through other analyses.