Electromagnetic scattering from absorbing spheres

Area of Science:

• Optical Physics
• Materials Science
• Computational Electromagnetics

Background:

• Mie theory is fundamental for understanding light scattering by particles.
• Calculating cross sections for absorbing particles is computationally intensive.
• The optical properties of particles depend significantly on their size and refractive index.

Purpose of the Study:

• To present an efficient computational method for Mie cross sections.
• To investigate the dependence of scattering and absorption efficiency factors on particle size and refractive index.
• To analyze the angular intensity function's half-width.

Main Methods:

• Development of an efficient algorithm for Mie cross section calculations.
• Systematic computation of efficiency factors (Q) for absorption and scattering.
• Analysis of the relationship between Q, size parameter (x), and refractive index (n1, n2).

Main Results:

• Scattering efficiency (Qsca) is proportional to the imaginary part of the refractive index (n2) within a specific range.
• Qsca exhibits a minimum and then a maximum as n2 increases for x >= 1.
• The half-width of the angular intensity function varies inversely with size parameter (x^-1) for x >= 10 and is largely independent of n1 and n2.

Conclusions:

• The developed method provides efficient calculation of Mie cross sections for absorbing particles.
• The study quantifies the influence of particle size and complex refractive index on scattering and absorption.
• Angular intensity characteristics are primarily size-dependent for larger particles.