Fabrication for Single-Mode Tapered Optical Waveguides for Spot-Size-Converter

For low-loss connection between silicon waveguides and conventional single-mode fibers, single-mode tapered polymer optical waveguides are fabricated using the Mosquito method, which work as a spot-size converter (SSC). In this research, the axially tapered shaped core is formed by accelerating the needle scan during the core dispense. In addition, the degradation of cross-sectional core shape from circle to ellipse is addressed by using a curved needle. The fabricated 12-mm long tapered waveguide with perfect circular core cross section exhibits an effective MFD conversion from 4.1 μm to 8.1 μm.