Optical self-switching of unidirectional distributively coupled waves

Theoretical and experimental fundamentals of the phenomenon of optical self-switching of unidirectional distributively coupled waves are presented. This waves represent a whole class of waves in optics: waves in tunnel-coupled optical waveguides, waves undergoing the Bragg diffraction, waves with different polarisations in an anisotropic (birefringent) waveguide or crystal, waves with different frequencies in a quadratically nonlinear medium, etc.