2. Understanding scattering media

2.1 Wave propagation in linear media

The foundations of geometrical optics were laid as far back as antiquity. This discipline interprets optical phenomena by considering only the direction of propagation of light energy, or light beam. A number of practical problems can be interpreted by geometrical optics: propagation through a diopter, systems using lenses, or wave confinement in an optical fiber with index hopping. However, geometrical optics does not take into account the wave-like nature of light, from which diffraction arises. This phenomenon is particularly important when light interacts with objects of characteristic dimensions of the same order of magnitude (or smaller) than the wavelength, and when we are interested in the resolution of an imaging system.

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