| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical modulator for suppressing a deterioration in an extinction ratio, and for suppressing a temperature drift phenomenon.SOLUTION: In an optical modulator comprising: a substrate having electro-optical effects; an optical waveguide formed on the substrate; and a control electrode for controlling an optical wave propagated through the optical waveguide, the optical waveguide has at least one Mach-Zehnder type optical waveguides (A1 to A3, B1 to B3), and the control electrode has DC electrodes (C1 to C4) for applying DB bias, and wiring for supplying the DB bias to the DC electrodes crosses one of two branch waveguides of the Mach-Zehnder type optical waveguides, and a first dummy electrode (dotted lines E5, E6) is provided at a specific position of the other branch waveguide, that is, a specific position which is relatively symmetrical to the position where the wiring crosses one branch waveguide.SELECTED DRAWING: Figure 2 |
