Silicon-integrated dual-mode fiber-to-chip edge coupler for 2 × 100 Gbps/lambda MDM optical interconnection

Abstract

In this work, a silicon-integrated edge coupler supporting dual-mode fiber-to-chip coupling was designed and fabricated on 220-nm-thick SOI wafer with standard CMOS-compatible fabrication process. The proposed low-complexity structure consists of a multimode interference and triple-tip inverse taper. Both LP₀₁ and LP₁₁ modes in the few mode fiber (FMF) can be stimulated simultaneously by the edge coupler from TE₀ and TE₁ modes in silicon waveguide. Such a design is compatible with broadband wavelength division multiplexing and can be scaled up to 4-polarization-mode coupling as well. Using the proposed edge coupler, 2×100-Gbps/lambda PAM4 multimode interface through dual-mode fiber was demonstrated successfully.