Negative refraction

The negative refraction is an abnormal phenomenon of Réfraction in electromagnetism, for which the wave refracted is propagated same side of the normal on the surface as the incidental wave. That amounts considering that the medium of refraction has an optical index of refraction negative N , or that the speed of phase $V\_\; \{\backslash \; phi\}\; =\; \backslash \; frac\; \{C\}\; \{N\}$ is negative. That does not violate the law of causality only if speed of phase and speed of group are opposite, which occurs in the electromagnetic Métamatériaux.

The negative refraction is a condition which would make it possible to carry out planar lenses with super-resolution (near to the rigorous stigmatism) proposed by John Pendry.

For the moment the negative refraction was observed in experiments that in the field of the microwaves.

See too

Ultra-refraction

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