Noncollinear triple acousto-optic diffraction of Bessel light beams by ultrasound in uniaxial crystals is investigated. An expression for the complex vector amplitude of a wave diffracted under exact Bragg synchronism conditions is obtained in vector-matrix form. The diffracted light beams display triple Bragg diffraction with different efficiencies when a Bessel light beam propagates at a small angle to the crystal optical axis. Diffraction where the diffracted light beams have the same intensity is possible if the Bragg synchronism conditions are exactly fulfilled. This diffraction feature is not observed without Bragg synchronism. The light intensity in the third diffraction order is significantly reduced (down to zero) with large frequency detuning of the Bragg synchronism.

研究了单轴晶体中超声波对贝塞尔光束的非共线三重声光衍射。以矢量-矩阵形式获得了在精确布拉格同步条件下衍射的波的复矢量幅度的表达式。当贝塞尔光束以与晶体光轴成小角度传播时，衍射光束显示出具有不同效率的三重布拉格衍射。如果完全满足布拉格同步条件，则衍射光束具有相同强度的衍射是可能的。如果没有布拉格同步，则无法观察到这种衍射特征。随着布拉格同步的大频率失谐，第三衍射级的光强度显着降低（降至零）。