光学学报, 2020, 40 (12): 1205001, 网络出版: 2020-06-03
层叠亚波长光栅中的模式匹配分析法 下载: 1541次封面文章
Analytical Mode Matching in Stacked Subwavelength Gratings
光纤光学 层叠亚波长光栅 模式匹配分析法 严格耦合波分析 导模共振 fiber optics stacked subwavelength grating analytical mode matching rigorous coupled wave analysis guide mode resonance
摘要
模式匹配分析法是计算亚波长光栅衍射效应的一种高效方法。对于亚波长层叠光栅,相邻的不同介质层边界处电磁场切向分量连续,每层中电磁场的各个波导模式对该层中电磁场的贡献与相邻层中电磁场切向分量的贡献相等,相邻层间模式匹配,故可将模式匹配分析法应用于亚波长层叠光栅中。通过具体实例比较了由模式匹配分析法与严格耦合波分析法计算得到的光栅衍射效率和电磁场强度分布,对比结果表明模式匹配分析法在分析亚波长层叠介质光栅方面相较于严格耦合波分析法更为高效,在收敛性以及计算速度方面有着独特的优势,且对于深刻理解层叠光栅对电磁波的衍射效应以及结合优化方法设计新型亚波长光栅、新型超表面方面具有重要意义。
Abstract
Analytical mode matching is an efficient method to calculate the diffraction of subwavelength grating. For stacked subwavelength gratings, the tangential component of an electromagnetic field is continuous at the boundary of adjacent different dielectric layers, and the contribution of each waveguide mode of the electromagnetic field in each layer to the electromagnetic field in the layer is equal to that of the tangential component of the electromagnetic field in the adjacent layer. The modes between adjacent layers are matched. Thus, the analytical mode matching can be applied to stacked subwavelength dielectric gratings. The diffraction efficiencies and the electromagnetic field distributions calculated using the analytical mode matching and the rigorous coupled wave analysis method are compared in this study. Comparison results show that the proposed analytical mode matching is an effective method for calculating the diffraction of stacked subwavelength dielectric gratings owing to its unique advantage in convergence and calculation speed and it offers a profound understanding of the diffraction effects of stacked subwavelength gratings on electromagnetic waves. The proposed method combined with optimization methods can be used to design new stacked subwavelength gratings and metasurfaces.
张锦龙, 史帅凯, 焦宏飞, 程鑫彬. 层叠亚波长光栅中的模式匹配分析法[J]. 光学学报, 2020, 40(12): 1205001. Jinlong Zhang, Shuaikai Shi, Hongfei Jiao, Xinbin Cheng. Analytical Mode Matching in Stacked Subwavelength Gratings[J]. Acta Optica Sinica, 2020, 40(12): 1205001.