Geometric Loss Reduction in Tight Bent Waveguides for Silicon Photonics

A low-loss bent waveguide with a Clothoid shape whose width is adjusted along the curvature is demonstrated. For a bend radius of 1.6 μm, the loss is reduced by 0.34 dB to less than 0.04 dB for a single S-shape bend when compared to a standard circular waveguide bend.