| 摘要 |
<p>PROBLEM TO BE SOLVED: To impart an excellent response characteristic to light waves guided through optical waveguides. SOLUTION: A signal electrode 26 is formed between two branch optical waveguides 24-1, 24-2 which constitute a Mach-Zehnder optical waveguide, and a first grounding electrode 27-1 and a second grounding electrode 27-2 are formed oppositely to the signal electrode 26 across the branch optical waveguides 24-1, 24-2. The signal electrode 26 is formed so that its electrode width varies continuously along a light wave guiding direction P and gets smaller along the wave guiding direction. Thus, the intervals between the side face 26A of the signal electrode 26 and the side faces 27-1A, 27-1B of the first grounding electrode 27-1 and the intervals between the side face 26B of the signal electrode 26 and the side faces 27-2A, 27-2B of the second grounding electrode 27-2 vary along the wave guiding direction P.</p> |
