Vol. 42, Issue 3, pp. 455-465 (2012)
Keywords
nonlinear optics, photorefractive medium, isotropic Kerr medium
Abstract
It is shown that the interaction of two strong pumps with four weak signal beams, not coplanar with the pump beam, gives rise to the exponential amplification of the weak beams in a Kerr-type negative medium. The theory developed is applied to the case of noise formation in iron-doped lithium niobate.