Hadibrata Wisnu, Wei Heming, Krishnaswamy Sridhar, Aydin Koray
Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Center for Smart Structures and Materials, Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Nano Lett. 2021 Mar 24;21(6):2422-2428. doi: 10.1021/acs.nanolett.0c04463. Epub 2021 Mar 15.
An inverse-designed metalens is proposed, designed, and fabricated on an optical fiber tip via a 3D direct laser-writing technique through two-photon polymerization. A computational inverse-design method based on an objective-first algorithm was used to design a thin circular grating-like structure to transform the parallel wavefront into a spherical wavefront at the near-infrared range. With a focal length about 8 μm at an operating wavelength of 980 nm and an optimized focal spot at the scale of 100 nm, our proposed metalens platform is suitable for two-photon direct laser lithography. We demonstrate the use of the fabricated metalens in a direct laser lithography system. The proposed platform, which combines the 3D printing technique and the computational inverse-design method, shows great promise for the fabrication and integration of multiscale and multiple photonic devices with complex functionalities.
通过双光子聚合的3D直接激光写入技术，在光纤尖端提出、设计并制造了一种逆设计超构透镜。基于目标优先算法的计算逆设计方法被用于设计一种薄的圆形光栅状结构，以在近红外范围内将平行波前转换为球面波前。在980nm的工作波长下，焦距约为8μm，焦斑在100nm尺度上得到优化，我们提出的超构透镜平台适用于双光子直接激光光刻。我们展示了在直接激光光刻系统中使用制造的超构透镜。所提出的平台将3D打印技术与计算逆设计方法相结合，在制造和集成具有复杂功能的多尺度和多种光子器件方面显示出巨大的前景。
