Diffractive grating based out-of-plane coupling between silicon nanowire and optical fiber

A diffractive grating in silicon was demonstrated for near vertical off-chip coupling between Silicon-on-insulator (SOI) photonic nanowire and optical fiber. By simulation, the coupling efficiency of 46% from nanowire to fiber was predicted. Finally, the grating coupler with the efficiency of 25% and 3-dB bandwidth of 45 nm was obtained.