Design of three-dimensional tapered SOI-based spot-size converter for C band

A three-dimensional tapered silicon-based spot-size converter is studied to improve the butt-jointed efficiency between the laser diode and the single-mode silicon waveguide. This kind of the spot-size converter can be fabricated while the ridge waveguide is etched. There is no need to regrow SiN or SiON on silicon. The optimized coupling efficiency between the spot-size converter and laser diode is over 0.8 at the wavelength of 1550 nm. This spot-size converter is useful for silicon photonics.