Discrete dipole approximation

The Discrete Dipole Approximation (DDA) is a mathematical way to simulate how light interacts with objects that are much smaller than the wavelength of light. Instead of thinking of the object as one big thing, DDA breaks the object up into lots of tiny pieces, and then calculates how each tiny piece interacts with the light. All of these tiny pieces together paint a picture of how the object interacts with the light as a whole.