Demonstration of a SiN Grating Coupler with a Metal Reflector on a Glass Substrate

초록

Realizing high-efficiency grating couplers (GCs) on glass substrates for high-bandwidth Co-packaged Optics (CPO) systems is challenging due to optical leakage into the substrate. In this work, we address this challenge by designing, fabricating, and characterizing a uniform silicon nitride (SiN) GC with an aluminum bottom reflector on a glass substrate. The device achieves a peak coupling efficiency of -5.1 dB and a 1-dB bandwidth of 47 nm, a 4.3 dB improvement over the non-reflector device. Furthermore, we demonstrate 106 Gbps Pulse Amplitude Modulation 4-level (PAM-4) transmission, confirming practical applicability. These results provide a valuable foundation for high-performance SiN GCs on a glass substrate platform, enabling their integration into advanced CPO for glass substrate-based optical interconnects in System-on-Wafer (SoW). © 1989-2012 IEEE.

키워드