脉冲波反射折射特性的分析计算

Analysis of pulsed reflection and refraction of electromagnetic waves

利用 FDTD法和 PML技术计算分析了平面分界面对脉冲波的反射和折射 ,充分而形象地描绘平面界面对脉冲波反射的时域过程。通过对折射波的分析获得下述结论 :当入射角小于临界角时 ,折射波波前与几何光学原理一致 ,当入射角大于临界角时 ,沿界面传播的折射波不是慢波 ,而是以媒质 的速度传播。所得结果有助于加深对脉冲波反射和折射性质的理解。

The reflection and the refraction of the pulse electromagnetic waves at a dielectric interface were calculated and analyzed based on the FDTD method and PML technique. The time-domain procedures of the pulse waves reflection were simulated with the contours and wavefront of electric field given. On the basis of analyzing the refracted wave, it was pointed out that the wavefront of the refracted wave corresponds with geometry optics if incidence angle is less than critical angle. On the contrary, the refraction wave propagating along with interface is not slow wave when the incidence angle is larger than critical angle. The results are quite helpful to understanding the reflecting and refracting behaviour of the pulse electromagnetic waves.