Low loss modified Bezier bend waveguide.

We proposed and experimentally demonstrated a low loss modified Bezier bend for silicon and silicon nitride photonic integrated circuits. Both simulation and experimental results confirm that the modified Bezier bend can effectively reduce the bend loss for silicon and silicon nitride platform. At a bend radius of 1 µm, the reduction of bend loss from 0.367 dB/90° of circular bend and 0.35 dB/90° of traditional Bezier bend to 0.117 dB/90° of modified Bezier bend for silicon platform was experimentally demonstrated. For a 12-µm radius silicon nitride bend, the bend loss reduction from 0.65 dB/90° of circular bend and 0.575 dB/90° of traditional Bezier bend to 0.32 dB/90° was achieved. The proposed modified Bezier bend design can also be applied to other material systems, such as InP, LN, GaAs, etc., to effectively reduce the bend waveguide loss.