The distributed feedback of counter-propagating waves in a periodically modulated medium with relaxing cubic nonlinearity

An interaction of two counter-propagating waves in a periodically modulated medium with relaxing cubic nonlinearity is considered. On the basis of analytical solutions of the equations under the weak distributed feedback (DFB) approximation, we show that an increase in the reflectivity of ‘nonlinear’ DFB-structures takes place due to phase mismatching between the radiation and the light-induced grating. We carry out a numerical simulation of the obtained equations for arbitrary values of the coupling coefficient, Bragg detuning and incident pulse intensity. We also analysed the dynamics of the regular temporal modulation of initially continuous wave radiation caused by the ‘nonlinear’ grating.