Maher Abdullah, Swillam Mohamed A
Department of Physics, The American University in Cairo, New Cairo, 11835, Egypt.
Sci Rep. 2025 Jan 15;15(1):2008. doi: 10.1038/s41598-024-83728-2.
Inverse design with topology optimization considers a promising methodology for discovering new optimized photonic structure that enables to break the limitations of the forward or the traditional design especially for the meta-structure. This work presents a high efficiency mid infra-red imaging photonics element along mid infra-red wavelengths band starts from 2 to 5 µm based on silicon nitride optimized material structures. The first two designs are broadband focusing and reflective meta-lens under very high numerical aperture condition (NA = 0.9). The two designs are modeled by inverse design with topology optimization problem with Kreisselmeier-Steinhauser (k-s) aggregation objective function, while the final design is depended on novel inverse design optimization problem with double aggregation objective function that can target bifocal points along the wavelength band producing high efficiency achromatic broadband multi-focal meta-lens under very high numerical apertures ([Formula: see text]).
基于拓扑优化的逆向设计是一种很有前景的方法，可用于发现新的优化光子结构，这种结构能够突破正向或传统设计的限制，特别是对于超材料结构而言。这项工作基于氮化硅优化材料结构，展示了一种高效的中红外成像光子元件，其工作波长范围为2至5微米的中红外波段。前两种设计是在非常高的数值孔径条件（NA = 0.9）下的宽带聚焦和反射超透镜。这两种设计通过带有Kreisselmeier-Steinhauser（k-s）聚集目标函数的拓扑优化问题进行逆向设计建模，而最终设计则依赖于具有双聚集目标函数的新型逆向设计优化问题，该函数能够在非常高的数值孔径下（[公式：见原文]）沿着波段瞄准双焦点，从而产生高效消色差宽带多焦点超透镜。
