周期性分层介质高反射区范围的分析与估计

Estimation method of high-reflecting region of periodic layered media

对于具有周期单元的分层介质材料高反射区的波长范围,提供一种简明的估计分析方法.基于Floquet定理,分析了有限周期单元分层介质的光子带隙特性,给出分层介质的高反射区波长范围.讨论了分层介质高反射区和周期单元禁带之间的关系.计算表明,高反射区和周期单元禁带的中心波长彼此一致.并且,随着分层介质周期单元数的增多,高反射区的深度和带宽就越接近于周期单元禁带的深度和宽度.最后,讨论周期分层介质的光子带隙特性与入射角及其与极化的变化关系.

A concise method of estimating high-reflection range for layered media composed of finite periodic unit is presented. Based on the Floquet theorem, the photonic bandgap properties of periodic layered media are analyzed, and the wavelength range of high-reflection region for periodic layered media is discussed. The relation between high-reflection region of layered media and forbidden band of the periodic unit is discussed. Numerical results show that the center wavelength of high-reflection region coincides with the one of the forbiddan band of periodic unit. Furthermore, as the periodic unit number of layered media is increased, the depth and width of high-reflection region become close to those of forbidden band of the periodic unit. Finally, the variations of photonic bandgap properties of periodic layered media with respect to the incidence angle and polarization have also been discussed.