Design and Optimization of MDM Fibers Using a Tunable Difference of Gaussian (DoG) Profile for Robust Cylindrical Vector Mode Transmission

Abstract

Mode-division multiplexing (MDM) using fiber cylindrical vector (CV) modes holds significant potential for enhancing optical communication capacity. However, designing fibers that effectively guide and separate CV modes with optimized performances remains challenging. This work presents a novel MDM fiber based on the Difference of Gaussian (DoG) function. It incorporates four tunable shape parameters to guide robust CV modes. The design trade-offs and performance metrics of the proposed DoG fiber are numerically investigated. The results demonstrate that the fiber supports CV modes with high modal separation (∆n<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</inf> > 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup>), indicating minimal channel crosstalk across the C+L ITU-T bands. Furthermore, the guided CV channels exhibit low differential group delays (DGD) and chromatic dispersion (CD), making the DoG fiber an excellent candidate for optical communication systems and/or other applications involving CV mode transmission through fibers.