Maxim Yurkin
Corea Rouen
website
The discrete dipole approximation for light-scattering simulations
Abstract: Electromagnetic scattering is widely used in remote sensing of various objects ranging from metal nanoparticles and macromolecules to atmospheric aerosols and interstellar dust. All these applications require accurate simulations, which are not trivial for particles of arbitrary shape and internal structure. The discrete dipole approximation (DDA) is one of the versatile methods to handle such problems. This talk will begin with an introduction to the DDA, covering both the basic underlying physical picture and a rigorous derivation starting from the integral form of Maxwell’s equation for the electric field. This derivation emphasizes that the DDA is a numerically exact method and a special case of volume-discretization method of moments. Notably, the DDA is applicable to almost any electromagnetic problem involving non-magnetic particles. It can handle arbitrary shaped beams, particles in complex environments (e.g., on a multi-layered substrate), and simulate a broad range of quasi-classical electromagnetic phenomena (such as emission enhancement, near-field radiative heat transfer, and electron energy-loss spectroscopy). I will also discuss computational aspects and modern DDA formulations. The latter are implemented in open-source DDA codes, such as ADDA, which largely explains the method’s popularity. Finally, I will highlight current capabilities and limitations (open questions) of the DDA.
