Design of high-efficiency and broadband SiN-on-SOI grating couplers based on CUMEC’s process platform

Silicon nitride-on-SOI grating couplers are specifically designed for the O- and C-bands, utilizing CUMEC's advanced process platform. Through simulation, we have achieved an impressive maximum coupling efficiency of -1.4 dB and -1.8 dB to standard single-mode fiber for the O- and C-bands respectively, accompanied by a remarkable 1-dB bandwidth of 70 nm and 78 nm. Furthermore, we have conducted an analysis on fabrication variation tolerance.