Аннотация:The influenct of optical nonlinearity of the parameters of dynamic scattering in cholesteric liquid crystals is described theoretically. The effect of nonlinear variation of the period of pendulum beatsin two-wave interaction is postulated and analyzed. A proceddure for second condensation of the wave equation is developed and then used to show that nonlinearity accelerates the process of difraction separation of energy between tha transmitted and scattered beams.