单负材料组成的周期结构中的快慢光

本文研究由介电系数和磁导率为负的材料组成的一维光子晶体中的电磁波脉冲的传播特性。利用传输矩阵的方法,计算出了该结构中脉冲传播的透射谱和相时间.数值结果表明,在光子带隙的带边和带底会分别出现脉冲传播速度减慢和加快的现象.若周期结构中间存在缺陷层,光子带隙中会出现极窄的透射峰,因此,对应于该频率的电磁波在该体系中传播时速度会变得更加缓慢.

Subluminal and Superluminal Pulse Propagation in Periodic Structures Containing Single-negative Materials

The propagation properties of an electromagnetic pulse in a one-dimensional photonic crystal (PC)composed of single-negative(permittivity-or permeability-negative)materials are studied in this paper.The transmission spectrum and delay time of the pulse propagating in the structure are calculated by using a transfer matrix method.The numerical results show that the subluminal pulse propagation and superluminal transmission can occur respectively at the band edge and in the photonic band gap.If a defect layer exists in the periodic structure,an extremely narrow transmission peak would appear in the photonic band gap.Therefore,the electromagnetic wave corresponding to that frequency will become slower when propagating in the defect mode.