Abstract:
It has been shown that counterpropagating electromagnetic waves with different frequencies generate two lattices in a cubically nonlinear medium, one of which moves at a superluminal velocity. When weak radiation reflects from the superluminal lattice, the wavefront is quasi-conjugated with distortions owing to the Doppler frequency shift. These effects occur both in insulators with fast nonlinearity and in an electron-positron vacuum.
Citation:
N. N. Rozanov, “Superluminal parametric Doppler effect in insulators and in an electron-positron vacuum”, Pis'ma v Zh. Èksper. Teoret. Fiz., 95:12 (2012), 689–692; JETP Letters, 95:12 (2012), 609–612