Design of a high-efficiency tapered silicon-cored-fiber coupler for fiber-to-chip coplanar edge coupling

A silicon-cored-fiber (SCF) is used in, what we believe to be, a novel way for coplanar light coupling from an incoming fiber to a silicon waveguide on a chip. Two schemes of utilizing SCFs are investigated, namely a tapered SCF coupler and a D-shaped SCF coupler. A tapered SCF coupler is chosen for further optimization, leading to a coupling efficiency of ∼97% obtained from the results of 3D FDTD simulation.