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Maxwell2D: Circle smaller than the wavelength

Dielectric constant distribution

When the particle size approaches the wavelength of the radiation then the front and back of the particle do not experience the same incident electric field and so there is interference of the scattered wave from the different parts of the particle. The result is that forward scattered waves constructively interfere and backscattered waves destructively interfere, i.e. there is a preference for forward scattering. The scattered amplitude in the animation is shown at five times its true amplitude. Atmospheric examples are a reduced backscatter for high-frequency cloud radars when looking at larger particles such as raindrops and large snowflakes and the corona around the sun when it passes through aerosol and haze particles.

Electric field animation

This is an animation of the component of the electric field out of the plane of the page.

Total field (incident plus scattered)       |      Scattered field (total minus incident)

Average Poynting vector

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.

Total field (incident plus scattered)       |      Scattered field (total minus incident)