标题： 作为具有源的真空的电介质媒介 显示英文标题

标题： Dielectric media considered as vacuum with sources

摘要： 传统教科书在讨论电磁波传播时，将感应电荷和电流密度视为“束缚”的，并因此将其纳入折射率中。 原则上，也应能够将介质视为真空，但带有显式的电荷和电流密度。 这提供了一种更直接、更物理的描述。 然而，在这种观点下，感应波在真空中传播，因此不容易理解波长与真空中波长不同的原因。 我们提供了解释，并附有相关的时间域仿真。 作为额外的收获，结果揭示了超材料的行为。 显示英文摘要

摘要： Conventional textbook treatments on electromagnetic wave propagation consider the induced charge and current densities as "bound", and therefore absorb them into a refractive index. In principle it must also be possible to treat the medium as vacuum, but with explicit charge and current densities. This gives a more direct, physical description. However, since the induced waves propagate in vacuum in this picture, it is not straightforward to realize that the wavelength becomes different compared to that in vacuum. We provide an explanation, and also associated time-domain simulations. As an extra bonus the results turn out to illuminate the behavior of metamaterials.