Subwavelength self-imaging in cascaded waveguide arrays  

作　　者：Wange Song Hanmeng Li Shenglun Gao Chen Chen Shining Zhu Tao Li 

机构地区：[1]Nanjing University,College of Engineering and Applied Sciences,National Laboratory of Solid State Microstructures,Key Laboratory of Intelligent Optical Sensing and Integration,Jiangsu Key Laboratory of Artificial Functional Materials,Nanjing,China [2]Collaborative Innovation Center of Advanced Microstructures,Nanjing,China

出　　处：《Advanced Photonics》2020年第3期29-34,共6页先进光子学（英文）

基　　金：The authors acknowledge the financial support from the National Key R&D Program of China(2017YFA0303701,2016YFA0202103);National Natural Science Foundation of China(91850204,11674167).Tao Li acknowledges support from Dengfeng Project B of Nanjing University.The authors have no conflicts of interest to disclose.

摘　　要：Self-imaging is an important function for signal transport,distribution,and processing in integrated optics,which is usually implemented by multimode interference or diffractive imaging process.However,these processes suffer from the resolution limit due to classical wave propagation dynamics.We propose and demonstrate subwavelength optical imaging in one-dimensional silicon waveguide arrays,which is implemented by cascading straight and curved waveguides in sequence.The coupling coefficient between the curved waveguides is tuned to be negative to reach a negative dispersion,which is an analog to a hyperbolic metamaterial with a negative refractive index.Therefore,it endows the waveguide array with a superlens function as it is connected with a traditional straight waveguide array with positive dispersion.With a judiciously engineered cascading silicon waveguide array,we successfully show the subwavelength self-imaging process of each input port of the waveguide array as the single point source.Our approach provides a strategy for dealing with optical signals at the subwavelength scale and indicates functional designs in high-density waveguide integrations.

关 键 词：SELF-IMAGING resolution limit silicon waveguide array photonic integration 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] O439[自动化与计算机技术—计算机科学与技术]