SEMICONDUCTOR OPTICAL WAVEGUIDE ELEMENT AND METHOD FOR MANUFACTURING SEMICONDUCTOR OPTICAL WAVEGUIDE ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor optical waveguide element including a spot size converter.SOLUTION: A semiconductor optical waveguide element 81 includes a third semiconductor mesa 55 in which a 31-st mesa portion 55b has an end face 55d that can be optically coupled, located at an edge of a substrate 11. The end face 55d can be optically coupled to an external optical waveguide. As the width of the 31-st mesa portion 55b and the width of a 32-nd mesa portion 55c of the third semiconductor mesa 55 are larger than the width of a second semiconductor mesa 49 in the semiconductor optical waveguide element 81, a mode field diameter equal to or close to a mode field diameter of the external optical waveguide can be imparted to an optical waveguide relating to the third semiconductor mesa 55. The width of the second semiconductor mesa 49 is smaller than the width of the 31-st mesa portion 55b and the width of the 32-nd mesa portion 55c of the third semiconductor mesa 55; and a first core layer 41 and a second core layer 53 are optically coupled to each other. Thereby, propagation of light proceeds from the first core layer 41 to the second core layer 53 or from the second core layer 53 to the first core layer 41.