title: Spontaneous hexagon formation in photorefractive crystal with a single pump wave.
abstract: A new scheme for spontaneous formation of hexagonal optical patterns in photorefractive crystals with dominant reflection gratings and a single pump wave is proposed and realized experimentally. It is shown theoretically that spontaneous hexagon formation results from random small-angle scattering of the pump wave inside the crystal. The threshold of spontaneous hexagon formation is found.
authors: P M
authors: PM
authors: Lushnikov
authors: A V
authors: AV
authors: Mamaev