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 spheroidal particles with small-to-large sizes. A spheroid is a very important nonspherical shape in modeling the optical properties of many natural particles. For the first time, we develop a computationally feasible separation of variables method (SVM) in spheroidal coordinates to compute optical properties of spheroids with small-to-large sizes compared to the wavelength of the incident light (lambda). The method is applicable to spheroids with size parameters (2 pi/lambda times the major semiaxis) up to at least 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.