Dual-Mode GVD Tailoring in a Convex Waveguide

Weicheng Chen,Gongcheng Yue,Tiegen Liu,Guo-Wei Lu,Haofeng Hu,Zhenzhou Cheng

doi:10.1109/jphot.2020.3005690

Abstract

Mode division multiplexing (MDM) silicon photonic integrated circuits (PICs) have been widely developed for achieving high-speed optical interconnects and communications. As an excellent nonlinear optical platform, silicon PICs also receive great attention in applications of optical parametric devices and nonlinear optical signal processing. However, it is still challenging to develop MDM optical parametric devices due to the strong mode dependence of the group velocity dispersion (GVD) in a silicon waveguide. Here, we theoretically design a convex waveguide exhibiting almost the same GVD profiles for quasi-TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and quasi-TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> modes based on the standard fabrication flow of silicon photonic foundries. Specifically, flat GVD curves varying from -1500 ps/nm/km to -1000 ps/nm/km are obtained for the two modes in a convex waveguide within a spectral region of 1.37 μm to 1.75 μm covering from E-band to U-band. The study is expected to open an avenue for exploring unprecedented MDM nonlinear applications.

Highlights

Mode divisionmultiplexing (MDM) silicon photonic integrated circuits (PICs) have great potential for scaling the bandwidth of optical interconnects and communications [1], [2]
Flat group velocity dispersion (GVD) curves varying from −1500 ps/nm/km to −1000 ps/nm/km are obtained for the two modes in a convex waveguide within a spectral region of 1.37 μm to 1.75 μm covering from E-band to U-band
It can be expected that a multi-mode waveguide with flat and overlap GVD profiles for all spatial modes could be useful for achieving Mode division multiplexing (MDM) optical parametric devices

Summary

Introduction

Mode division (de)multiplexing (MDM) silicon photonic integrated circuits (PICs) have great potential for scaling the bandwidth of optical interconnects and communications [1], [2] In such technique, spatial orthogonal modes in a multimode waveguide are utilized as distinct information channels, providing an additional degree of freedom to boost information capacity of optical networks together with other (de)multiplexing techniques, such as time division (de)multiplexing [3], wavelength division (de)multiplexing [4] and polarization division (de)multiplexing [5]. It can be expected that a multi-mode waveguide with flat and overlap GVD profiles for all spatial modes could be useful for achieving MDM optical parametric devices. Our study is expected to open an avenue for exploring unprecedented MDM optical parametric devices and nonlinear optical signal processing applications on a chip

Design Principle and GVD Tailoring

Conclusions