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Dielectric constant distribution
|A small point with a different refractive index to its surroundings oscillates as a dipole under the influence of the incident electric field, and reradiates energy in all directions. In this case the dielectric constant of 1.78 corresponds to a refractive index of 1.333, which is the value for liquid water illuminated by visible light. The scattered energy is much less than the incident energy, so the scattered amplitude in the animation is shown at 50 times its true amplitude (although the colours in the Poynting vector of the total and scattered fields are correct relative to each other). In 3D this is known as Rayleigh scattering and atmospheric examples are scattering of sunlight by molecules and scattering of weather radar beams by cloud and rain droplets. Now see what happens when the same particle is illuminated by two frequencies simultaneously.|
Wikipedia link: Rayleigh scattering
This is an animation of the component of the electric field out of the plane of the page.
The direction in which energy is travelling at any instant is proportional to the cross product of the electric and magnetic fields, known as the Poynting vector. The arrows show the direction of the Poynting vector averaged over the simulation, while the colours show its strength.