利用传输矩阵法理论,计算、研究周期数对双周期对称结构一维光子晶体透射谱的影响,结果发现:当光子晶体为单周期对称结构时,随着周期数的增大,透射谱中透射峰的带宽会越来越窄;当光子晶体为双周期对称结构时,随着外层光子晶体周期数的增大,透射谱中的能带逐渐振荡最后分裂成分立的窄透射峰,随着内层光子晶体周期数的增大,透射谱中的分立透射峰向禁带中心靠拢,形成简并的趋势,而且透射峰带宽也会越来越窄。周期数对双周期对称结构一维光子晶体透射特性的调制规律,为光子晶体设计光学滤波、光学开关等新型光学器件提供理论依据。
The transmission spectrum of the double periodic symmetric structures is studied by using the transfer matrix method. The results show that: In the single periodic symmetric structure photonic crystal,when the period number increases the bandwidth of the transmission peak becomes narrower. In the double periodic symmetric structure photonic crystal,when the period number of external photonic crystal increases,energy band of the transmission spectrum gradually oscillates and finally fractures into separated narrow transmission peaks; when the period number of internal photonic crystal increases,separated transmission peaks of the transmission spectrum will draw close to the forbidden band center forming a degenerate tendency,and the bandwidth of the transmission peak will become narrower. Modulation of double periodic symmetric structure photonic crystal by period number will provide theoretical foundation for the design of new photonic crystal optical devices such as optical filter,optical switch and so on.