Wave front reversal with angular tilting-theory and experiment for the four wave mixing

A scheme of wave front reversal in four wave mixing (WFR-FWM) with angular tilting of the reversed wave is proposed, theoretically discussed and experimentally realized. It is based on detuning from counterpropagation of reference waves. Unlike the proper WFR-FWM, tilting on the angle γx reversal is effective only for the signal directions near the synchronism cone. when γx ⪡ 1 this cone is almost the plane which is perpendicular to the turning direction, and the angular width of effective reversal across the plane is δθx ∽ (kLγx)-1 where L is the depth of the nonlinear medium, k = 2π/λ. The experimental investigation of the interaction of λ = 1.06 μm radiation with the saturable dye solution for the tilting angle γx up to 10-2 rad was carried out. The measured angular selectivity of tilting reversal corresponds to the theoretical one. The energetic fraction of an ideally reversed field in the whole reflected wave was quantitatively measured.