PLC-Based LP11 Mode Rotator With Curved Trench Structure Devised From Wavefront Matching Method

A compact and low-loss PLC-based mode rotator is proposed. The mode rotator with the curved trench structure is designed based on the wavefront matching method, which is an optimization algorithm based on the beam propagation method. The proposed mode rotator is 45% in size (1 mm) and has lower loss (1/5) compared with the conventional structure that has a straight trench. Furthermore, the proposed mode rotator can achieve low-mode crosstalk.