We consider collinear acousto-optic diffraction of circularly polarized optical waves at circularly polarized acoustic waves in the crystals that reveal both acoustic conical refraction and optical activity. We find that, due to the conical refraction of acoustic waves, these waves produce vector-vortex beam. In this process, the orbital angular momentum (OAM) of the conically refracted acoustic wave is transformed into the OAM of the diffracted optical wave. At the same time, the spin angular momentum of conically refracted phonons is transferred to diffracted photons. The possibility of phonon-photon entanglement is discussed in the work.

中文翻译：

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在共线声光衍射中声波和光波之间的角动量交换

我们考虑圆偏振光波在晶体中的圆偏振声波处的共线声光衍射，这揭示了声锥折射和光学活动。我们发现，由于声波的锥形折射，这些波产生矢量涡旋光束。在这个过程中，锥形折射声波的轨道角动量（OAM）转化为衍射光波的OAM。同时，锥形折射声子的自旋角动量被转移到衍射光子。工作中讨论了声子-光子纠缠的可能性。