The negative refraction in uniaxialcrystal is different from that in left-handed materials, it is one special property of the uniaxialcrystal, and the other one is negative reflection.
单轴晶体中的负折射现象和左手材料中的负折射有着本质上的区别，它是单轴晶体的一种特殊属性。
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The refractive indices at 12 wave lengths in the visible region were measured with the minimum deviation method, showing that KABO is a negativeuniaxial optical crystal with moderate birefringence.