  We study the light propagation in one-dimensional photonic crystal via
nonlinear Four Wave Mixing (FWM) process. The linear and nonlinear refractive
indexes are approximated with the first Fourier harmonic term. A system of the
nonlinear coupled mode equations (NLCMEs), including pump fields depletion is
derived for FWM process and steady state analysis is presented numerically.
Also some of important system parameters' effects on FWM process are
investigated. It has been shown that, although we have considered pump
depletion and used a medium with 3rd order succeptibility which is small
compared to the 2nd order succeptibility, conversion efficiency is enhanced at
least 100 times to the previous works which had used undepleted pump
approximation and amedium with 2nd order succeptibility.
