Highly efficient and perfectly vertical chip-to-fiber dual-layer grating coupler

摘要: A novel high-efficiency silicon-chip-to-fiber grating coupler is investigated here. By introducing a dual layer structure with an inter-layer lateral shift to mimic 45° tilted mirror behavior, perfectly vertical coupling successfully demonstrated. Our numerical results show that peak efficiency about 70% possible near 1550 nm. Meanwhile, for the entire telecom C-band, i.e. wavelengths from 1530 nm 1565 nm, > 50% and back reflection less than < 1%. proposed high-performance silicon suitable interfacing multi-core fiber platform, which may play important role in future CMOS photonic integration technology.