Lorenz-Mie Theory-Type Solution for Light Scattering by Spheroids with Small-to-Large Size Parameters and Aspect Ratios

There has been a long-term endeavor in the light-scattering research community to develop a Lorenz-Mie theory-type method for simulating light scattering by the spheroidal particles with small-to-large sizes, which is a very important nonspherical shape in modeling the optical properties of many realistic particles. For the first time, we develop a computationally feasible separation of variable method (SVM) in the spheroidal coordinates to compute optical properties of spheroids with small-to-large sizes compared to the wavelength of the incident light (λ). The method is applicable to spheroids with size parameters (2π⁄λ times the major semiaxis) up to 600, and is not restricted by particle aspect ratios. Therefore, the work reported here represents a breakthrough in solving the optical properties of a nonspherical particle in an analytical form.