Crosstalk reduction of integrated optical waveguides with nonuniform subwavelength silicon strips

Yang Yang,Yijia Huang,Yanqin Wang,Mingbo Pu,Yinghui Guo,Xiaoliang Ma,Xiong Li,Xiangang Luo

doi:10.1038/s41598-020-61149-1

Abstract

Suppression of the crosstalk between adjacent waveguides is important yet challenging in the development of compact and dense photonic integrated circuits (PICs). During the past few years, a few of excellent approaches have been proposed to achieve this goal. Here, we propose a novel strategy by introducing nonuniform subwavelength strips between adjacent waveguides. In order to determine the widths and positions of nonuniform subwavelength strips, the particle swarm optimization (PSO) algorithm is utilized. Numerical results demonstrate that the coupling length between adjacent waveguides is increased by three (five) orders of magnitude in comparison with the case of uniform (no) subwavelength strips. Our method greatly reduces crosstalk and is expected to achieve a highly compact integrated density of PICs.

Highlights

Suppression of the crosstalk between adjacent waveguides is important yet challenging in the development of compact and dense photonic integrated circuits (PICs)
Much attention has been paid on the development of silicon photonics because of its compatibility with complementary metal oxide semiconductor (CMOS) technology[1,2]
Subwavelength silicon gratings have been brought into optical waveguide and on-chip architectures to provide new degrees of freedom to control the guided wave in PICs18–21

Summary

Introduction

Suppression of the crosstalk between adjacent waveguides is important yet challenging in the development of compact and dense photonic integrated circuits (PICs). Experimental results indicated that all-dielectric metamaterials can achieve a highly constrained mode and the coupling length is increased by ten times compared to the case without subwavelength strips.

Results

Conclusion