An effective holographic amplifier exploiting consistent periodic structures

The energy transfer between interacting laser beams is known as the remarkable effect of self-action of coherent waves in nonlinear optics. We demonstrate both experimentally and theoretically that such an effect can be obtained in a holographic setup based on a permanent phase dual-grating. We have found a new mode of unidirectional energy transfer from a strong pump beam to a weak signal beam, achieved through their diffraction on a set of two matched thin gratings. A theoretical description of this effect is developed based on a system of coupled waves and the formalism of generation of a shifted (nonlocal) dynamic grating with a spatially localized amplitude due to wave-mixing inside a bulk medium. Under the condition of a decrease in the intensity of a weak signal beam, the theory predicts almost complete energy transfer with a diffraction efficiency of ∼ 100