Yet another look at light scattering from particles in absorbing media

Area of Science:

• Optics and Photonics
• Materials Science
• Computational Physics

Background:

• Traditional scattering analysis often relies on energy flux measurements through integrating spheres.
• Existing models can be complex, involving arbitrary reference planes and particle locations.
• Understanding particle interactions within absorbing media is crucial for various optical applications.

Purpose of the Study:

• To fundamentally redefine the concept of extinction for particles within absorbing media.
• To develop a more robust and location-independent definition of the extinction cross section.
• To simplify the theoretical framework for analyzing light scattering phenomena.

Main Methods:

• Examined extinction based on the fundamental definition: energy removed from the incident plane wave.
• Analyzed the energy detected after traversing the absorbing medium with and without the particle.
• Derived the extinction cross section by considering pathlength dependence and particle position independence.

Main Results:

• The detected energy comprises two terms: baseline transmission and a particle-induced correction.
• Both energy terms exhibit identical pathlength dependence.
• The extinction cross section definition was found to be independent of particle location and reference planes.

Conclusions:

• The study provides a simplified and more fundamental definition of extinction cross section.
• This new definition enhances the analysis of scattering properties in absorbing media.
• The findings offer a more versatile approach to optical characterization of particles.