Anisotropic leaky-like perturbation with subwavelength gratings enables zero crosstalk

作     者：Md Faiyaz Kabir Md Borhan Mia Ishtiaque Ahmed Nafiz Jaidye Syed Z.Ahmed Sangsik Kim Md Faiyaz Kabir;Md Borhan Mia;Ishtiaque Ahmed;Nafiz Jaidye;Syed Z.Ahmed;Sangsik Kim

作者机构：Department of Electrical and Computer EngineeringTexas Tech UniversityLubbockTX 79409USA Department of Physics and AstronomyTexas Tech UniversityLubbockTX 79409USA School of Electrical EngineeringKorea Advanced Institute of Science and TechnologyDaejeon 34141South Korea 

出 版 物：《Light(Science & Applications)》 (光（科学与应用)（英文版）)

年 卷 期：2023年第12卷第6期

页      面：1153-1161页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：This material is based upon work supported by the National Science Foundation under Grant No.2144568 and No.1930784 This work was performed,in part,at the Center for Integrated Nanotechnologies(CINT),an Office of Science User Facility operated for the U.S.Department of Energy Office of Science by Los Alamos National Laboratory and Sandia National Laboratories.This work was partially supported by the National Research Foundation of Korea(NRF)funded by the Korea government(MSIT)(No.RS2023-00210997).S.K.acknowledge the support from the KAIST new faculty research fund. 

主　　题：crosstalk coupling enable 

摘      要：Electromagnetic coupling via an evanescent field or radiative wave is a primary characteristic of light,allowing optical signal/power transfer in a photonic circuit but limiting integration density.A leaky mode,which combines both evanescent field and radiative wave,causes stronger coupling and is thus considered not ideal for dense integration.Here we show that a leaky oscillation with anisotropic perturbation rather can achieve completely zero crosstalk realized by subwavelength grating(SWG)metamaterials.The oscillating fields in the SWGs enable coupling coefficients in each direction to counteract each other,resulting in completely zero crosstalk.We experimentally demonstrate such an extraordinarily low coupling between closely spaced identical leaky SWG waveguides,suppressing the crosstalk by≈40 dB compared to conventional strip waveguides,corresponding to≈100 times longer coupling length.This leaky-SWG suppresses the crosstalk of transverse–magnetic(TM)mode,which is challenging due to its low confinement,and marks a novel approach in electromagnetic coupling applicable to other spectral regimes and generic devices.