| 摘要 |
PROBLEM TO BE SOLVED: To provide a coherent mixer reducing a deviation between channels.SOLUTION: The coherent mixer has a multimode semiconductor waveguide. The multimode semiconductor waveguide includes: a first side face 13a that extends from a side face 19a of a first semiconductor region 19 extending along the first side face 13a of the multimode semiconductor waveguide, with an interval W1 of a reference value or less; and a second side face 13b that extends from a side face 21a of a second semiconductor region 21 extending along the second side face 13b of the multimode semiconductor waveguide, with an interval W2 of a reference value or less. Thus, a difference between the heights of the first side face 13a and the second side face 13b of the multimode semiconductor waveguide and the heights of first to m-th semiconductor waveguides (for example, semiconductor regions 15a, 15b, 15c, 15d) is reduced when the multimode semiconductor waveguide, a first group of semiconductor regions 15, the first semiconductor region 19, and the second semiconductor region 21 are processed by etching collectively, thereby reducing the deviation of the coherent mixer. |
