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arXiv 1706.06263physics.optics
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全反射条件下电磁场的动力学特性

Dynamical characteristics of electromagnetic field under conditions of total reflection

Aleksandr Bekshaev

摘要:

电磁场的动力学特性包括能量、动量、角动量(自旋)和螺旋度。分析了任意偏振的单色平面波入射到两种透明非色散介质的平面界面附近时,在较低光密度的介质中形成倏逝波时,它们的空间分布。基于最近支持材料介质中电磁动量的Minkowski定义的论点[Phys.Rev.A83,013823(2011); 86,055802(2012); Phys.Rev.Lett.2012],119,073901(2017)],我们推导出两种介质中动力学特性的显式表达式,特别注意它们在界面处的行为。特别是,“非凡的”自旋和动量分量的入射平面正交的描述,和规范(自旋轨道)动量分解进行,不包含奇异项。场能量、螺旋度、自旋动量和轨道动量分量处处规则,但在界面处不连续;平行于界面的自旋分量似乎是连续的,这证明了所采用的闵可夫斯基图像的一致性。该结果为非均匀介质中空间自由度和偏振自由度分离的电磁动量分解提供了一个有意义的例子,可用于工程上设计用于光学分选、调度和微操作的结构场。

英文摘要:

The dynamical characteristics of electromagnetic fields include energy, momentum, angular momentum (spin) and helicity. We analyze their spatial distributions near the planar interface between two transparent and non-dispersive media, when the incident monochromatic plane wave with arbitrary polarization is totally reflected, and an evanescent wave is formed in the medium with lower optical density. Based on the recent arguments in favor of the Minkowski definition of the electromagnetic momentum in a material medium [Phys. Rev. A 83, 013823 (2011); 86, 055802 (2012); Phys. Rev. Lett. 119, 073901 (2017)], we derive the explicit expressions for the dynamical characteristics in both media, with special attention to their behavior at the interface. Especially, the "extraordinary" spin and momentum components orthogonal to the plane of incidence are described, and the canonical (spin - orbital) momentum decomposition is performed that contains no singular terms. The field energy, helicity, the spin momentum and orbital momentum components are everywhere regular but experience discontinuities at the interface; the spin components parallel to the interface appear to be continuous, which testifies for the consistency of the adopted Minkowski picture. The results supply a meaningful example of the electromagnetic momentum decomposition, with separation of spatial and polarization degrees of freedom, in inhomogeneous media, and can be used in engineering the structured fields designed for optical sorting, dispatching and micromanipulation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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