Enhancement effect of phase-conjugate waves of third order nonlinear medium in the Bragg microcavity

The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a (AB)~N(D)~2(BA)~N Bragg microcavity made of one-dimensional photonic crystals is studied.The gain factor of the phase-conjugate wave is derived when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode.Because of stronger resonance enhancement to incident pump beam given by the Bragg microcavity,the enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium inside Bragg microcavity is more outstanding than that caused by the naked third order nonlinear optical medium.The theoretical analysis and the numerical calculation show the Bragg microcavity with larger number N of periods is identical with a Fabry-Perot cavity when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode.