Snell law

Snell's Law

Refraction

Snell's law (also called Snell-Descartes law) is a formula used to calculate the refractive angle of light by traversing the separation surface between two means of propagating light (or any electromagnetic wave) with a refractive index. different. The name comes from its discoverer, the Dutch mathematician Willebrord Snel van Royen (1580-1626). They named her "Snell" because of her last name but they put two "l" for her name Willebrord which carries two "l".

It affirms that the multiplication of the refractive index by the sine of the angle of incidence with respect to the normal is constant for any ray of light incident on the separating surface of two media. That is, the component of the refractive index parallel to the surface is constant. Although Snell's law was formulated to explain the phenomena of refraction of light it can be applied to all types of waves crossing a separation surface between two media in which the velocity of propagation of the wave varies.