Kupreychik Maxim I, Balakshy Vladimir I
Appl Opt. 2018 Jul 10;57(20):5549-5555. doi: 10.1364/AO.57.005549.
With the example of an alpha-iodic acid crystal, we demonstrate the unusual peculiarities of acousto-optic interaction in gyrotropic biaxial crystals. Basic attention is given to the most interesting cases of anisotropic diffraction in geometry, when the wave vector of ultrasound is directed almost orthogonally to one of the optical axes, and the directions of incident and diffracted light beams are close to the optical axis. It is shown that in this case a peculiar character of optical anisotropy originates unique variants of acousto-optic interaction that are fundamentally impossible in uniaxial crystals. A wide variety of frequency dependences of the Bragg angles allows choosing optimal configurations of crystal cuts for each specific acousto-optic device. The influence of the effect of optical activity on diffraction characteristics is examined as well.
以α-碘酸晶体为例，我们展示了旋光性双轴晶体中声光相互作用的异常特性。重点关注了几何结构中各向异性衍射最有趣的情况，即超声的波矢几乎垂直于其中一个光轴，且入射光束和衍射光束的方向接近光轴。结果表明，在这种情况下，光学各向异性的特殊性质产生了声光相互作用的独特变体，这在单轴晶体中根本不可能出现。布拉格角的多种频率依赖性使得能够为每个特定的声光器件选择最佳的晶体切割配置。同时也研究了旋光效应对衍射特性的影响。
