Spot-Size-Adjustable Optical Mediator using 3D-Tapered Silica Waveguides for SiPh/SMF Low-Loss Connection

We propose an optical mediator using 3D-tapered silica waveguides for standard-singlemode fiber to silicon-waveguide connections, achieving adjustable spot sizes ($3-9 \mu \mathrm{~m}$), precise pitch conversion, and ${\lt}0.7-\mathrm{dB}$ coupling loss for TE-mode in the LAN-WDM band.