晶格常数对光子晶体量子阱透射谱的影响

Effect of lattice constants on transmission spectra of photonic crystal quantum well

为设计高品质光学滤波器、光开关等量子光学器件,用传输矩阵法理论研究晶格常数对一维光量子阱(AB)5(CD)2(BA)5透射谱的影响,结果发现:当A、B介质层的晶格常数偶数倍增加时,禁带中心频率处的窄透射峰变成宽透射带,透射带两侧对称分布着2条透射率为100%的窄透射峰;当A介质层的晶格常数奇数倍增加时,禁带中心频率处出现透射率为100%单条窄透射峰;当B介质层的晶格常数奇数倍增加,或D介质层的晶格常数按整数倍增加时,禁带中心频率处恒定出现3条透射率为100%的窄透射峰,且三者之间距离随着B、D介质层晶格常数的增大而逐步向禁带中心靠拢;当D介质层晶格常数按整数增加时,不仅禁带中心频率处恒定出现3条透射率为100%的窄带透射峰,同时两侧对称出现与晶格常数倍数密切相关的双透射峰结构,且双透射峰的透射率随晶格常数倍数增大而增高。这些特性可实现可调通道光滤波和光开关功能,并为实验制备工作提供理论指导。

To design high-quality optical devices, such as filters and switches, the effect of lattice constant on the transmission spectra of one-dimensional optical crystal quantum well（AB）s（CD）z（BA）~ was studied with transfer matrix method. The result shows that when the lattice constants of layer A and layer B separately increase with even times, the narrow transmission peaks at center frequency of band gap turns into wide transmission band, both sides of which are symmetrically distributed with two narrow transmission peaks of 100% transmittance; when lattice constants of layer A increases with odd times, a single transmission peak of 100% transmittance appears at the center frequency; when the lattice constants of layer B increases with odd times or that of layer D increases with integral multiple, three transmission peaks of 100% transmittance constantly turn up at the center frequency of band gap, and the three ones draw closer to the center of band gap as lattice constants of layer B and D are increasing; when lattice constant of layer D increases with integral multiple, three transmission peaks of 100% transmittance constantly present at the center frequency of band gap, besides, double-transmission-peak structure, which is closely related to the lattice constants,symmetrically appears on its two sides. Meanwhile, the transmittances of each double-transmission-peak enlarge with the integral multiple of lattice constants increasing. All these features can be applied to adjustable-channel optical filtering and switching, and can offer theoretical direction for experiment preparation.