论文标题
梁的挠度和负面培养基中的负面阻力
Beam deflection and negative drag in a moving nonlinear medium
论文作者
论文摘要
在带有统一以外的折射率的移动介质中传播的光会导致轻度阻力。尽管线性折射率引起的轻拖动效应通常很小，但在具有较大组索引的材料中可以增强它。在这里，我们表明，非线性折射率也可以在移动介质的光传播中发挥关键作用，并导致梁偏转可能与横向阻力效应相混淆。我们对旋转红宝石晶体进行实验，该实验表现出非常大的负组指数和阳性非线性折射率。负组指数将与介质运动相反的光拖动光。然而，阳性非线性折射率使梁偏向介质的运动，并阻碍观察负阻力效应。因此，我们表明，不仅有必要测量梁的横向移位，而且还必须测量其输出角度，以区分光拖层与光束偏转的效果 - 早期实验中缺少的关键步骤。
Light propagating in a moving medium with refractive index other than unity is subject to light drag. While the light drag effect due to the linear refractive index is often negligibly small, it can be enhanced in materials with a large group index. Here we show that the nonlinear refractive index can also play a crucial role in propagation of light in moving media and results in a beam deflection that might be confused with the transverse drag effect. We perform an experiment with a rotating ruby crystal which exhibits a very large negative group index and a positive nonlinear refractive index. The negative group index drags the light opposite to the motion of the medium. However, the positive nonlinear refractive index deflects the beam towards the motion of the medium and hinders the observation of the negative drag effect. Hence, we show that it is necessary to measure not only the transverse shift of the beam, but also its output angle to discriminate the light-drag effect from beam deflection -- a crucial step missing in earlier experiments.
