LAUSR

We present the design of a diffractive grating structure and get the optimal parameters which can achieve more than 75% coupling efficiency (CE) between single-mode fiber and silicon-on-insulator (SOI) waveguide through 2D finite-different time-domain (FDTD) simulation. The proposed architecture has a uniform structure with no bottom reflection element or silicon overlay. The structure, including grating couplers, adiabatic tapers and interconnection waveguides can be fabricated on the SOI waveguide with only a single electron-beam lithography (ICP) step, which is CMOS-compatible. A relatively high coupling efficiency of 47.2% was obtained at a wavelength of 1562 nm.