摘要 |
A method for making a polarization rotator includes the steps of forming a structure including a semiconductor substrate and a mesa part, forming a first semiconductor layer on a main surface of the semiconductor substrate and around the mesa part, forming a second semiconductor layer on the first semiconductor layer, forming a semiconductor laminate by forming a third semiconductor layer on the second semiconductor layer, forming a mask layer on the third semiconductor layer, forming a mesa including a first semiconductor core by etching the semiconductor laminate, and forming a first semiconductor cladding by forming a fourth semiconductor layer around the mesa. The first semiconductor core and the first semiconductor cladding form a polarization rotating unit. An inclined surface of a mesa-part-adjacent portion extends in a second direction forming an acute angle with the main surface. An inclined portion of the second semiconductor layer extends in the second direction. |