有限开敞介质光子晶体的模式及其带结构分析

Mode and band analysis of finite dielectric photonic crystals

针对光子晶体在行波管中的应用,对有限开敞介质光子晶体的模式和带结构进行了分析和计算.分析表明,有限开敞介质光子晶体中所能存在的模式包括EH和HE混合模式,如果是二维光子晶体,还存在E模式,E1模式即为无限光子晶体中的E极化.计算表明,被用作行波管慢波电路的光子晶体可以不必拥有完全带隙,而只需要具有带间隙即可.

In this article, dielectric photonic crystals （PhC） with finite dimensions and exposed in air is analyzed for its potential value in traveling wave tubes （TWTs）. The modes existing in finite dielectric PhC are EH and HE, and also E if the finite PhC is two-dimensiond. The E1 mode is the E polarization in infinite dielectric PhC. Calculation shows that only the existence of gaps of pass-bands is necessary for PhC in TWTs, while the complete photonic crystal band gaps are superfluous.