Light Scattering Reviews 5

Viac o knihe

Light scattering by densely packed inhomogeneous media presents significant challenges in optics, typically requiring approximate methods for calculations. However, when only a few macroscopic scattering particles are in contact, exact results can be achieved by solving Maxwell’s equations. Simulations are feasible for a limited number of particles, especially if their sizes exceed the wavelength of incident light. The first review chapter in Part I, authored by Yasuhiko Okada, discusses modern numerical techniques for simulating the optical characteristics of densely packed spherical particle groups. Mie theory falls short in accuracy due to the strong interactions among particles in their near field, necessitating the solution of Maxwell’s equations for the entire ensemble rather than individual particles. The author outlines methods for generating aggregate shapes and performs orientation averaging through numerical integration with respect to Euler angles. Various numerical techniques are detailed, including the T-matrix method, discrete dipole approximation, finite difference time domain method, effective medium theory, and generalized multi-particle Mie solution. Recent advancements, such as the grouping and adding method and Monte Carlo-based numerical orientation averaging, are also thoroughly examined.