Finite-difference time-domain solution of light scattering by arbitrarily shaped particles and surfaces

The scattering and absorption of electromagnetic waves by irregularly shaped particles and arbitrary surfaces occur in the atmosphere, ocean, and optical devices. In this chapter, we present the finite-difference time-domain (FDTD) method [1–6] that can be used to calculate light scattering by arbitrary particles and surfaces. The FDTD technique is a numerical solution to Maxwell’s equations and is formulated by replacing temporal and spatial derivatives in Maxwell’s equations with their finite-difference equivalences. This method can be accurately applied to general electromagnetic structures including arbitrary particles and surfaces. The FDTD technique has been successfully applied to calculate light scattering and absorption by particles of different shapes in free space [5] and in absorbing medium [6]. Recently, an advanced FDTD model to calculate the interaction of electromagnetic radiation with arbitrary dielectric surfaces has been developed [7]. In the following sections, these FDTD light-scattering models are reviewed.