LAUSR

A compact silicon photonic grating coupler enabling fiber-to-chip light coupling at a minimized footprint is proposed. The proposed coupler, which is partially overlaid at the tapered region, downsizes the effective length of the spot-size converter to 60 μm while reducing the lateral height and width adiabatically to 220 nm and 320 nm, respectively. The incorporation of such a coupler in a photonic integrated circuit requires a total physical length and width of 75 μm and 14 μm, respectively, to enable effective interfacing with single mode fiber. The coupling efficiency and bandwidth of the structure at the light wavelength of 1550 nm are quantified as 68% and 67 nm, respectively, which outperform most recent demonstrations.