Mugnai D, Mochi I
Nello Carrara Institute of Applied Physics CNR, Via Panciatichi 64, 50127 Firenze, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Jan;73(1 Pt 2):016606. doi: 10.1103/PhysRevE.73.016606. Epub 2006 Jan 13.
The electromagnetic propagation of a Bessel-X wave is analyzed on the basis of a vectorial treatment in order to obtain information about the propagation of energy flux and the velocity of the energy. Knowledge of these quantities is of great interest since they are connected to the production of localized electromagnetic energy and to the topic of superluminality, respectively. The electric and magnetic fields are obtained in the far-field approximation by considering a realistic situation able to generate a Bessel-X wave. The vectorial treatment confirms the capability of this kind of wave to localize energy, while, quite surprisingly, even if the group velocity is superluminal, the energy velocity is equal to the light speed.
为了获取有关能流传播和能量速度的信息，基于矢量处理方法对贝塞尔-X波的电磁传播进行了分析。了解这些量非常重要，因为它们分别与局域电磁能的产生以及超光速主题相关。通过考虑一种能够产生贝塞尔-X波的实际情况，在远场近似下得到了电场和磁场。矢量处理方法证实了这种波具有局域能量的能力，而令人惊讶的是，即使群速度是超光速的，能量速度却等于光速。
