The structure and dynamics of the four-wave mixing transmission grating in a photorefractive crystal were investigated. The steady-state grating’s amplitude distribution looks like a motionless soliton. When the value of coupling strength is more than 2, there are three solutions for the steady-state grating: two stable and one unstable. The dynamics of all these gratings are described by the sine-Gordon equation. The four-wave mixing grating’s structure and location in space are determined by the input beams’ ratio, phase difference, or both.
[Optical Society of America ]
S. A. Bugaichuk and A. I. Khizhnyak, "Steady state and dynamic gratings in photorefractive four-wave mixing," J. Opt. Soc. Am. B 15, 2107-2113 (1998)