| 摘要 |
PROBLEM TO BE SOLVED: To achieve size reduction.SOLUTION: A waveguide substrate 111 on which a light guide 112 and a plurality of electrodes 121 for applying an electrical signal to the light guide 112; a relay substrate 102a arranged adjacent to the waveguide substrate 111; and a termination substrate 102b arranged opposite to the relay substrate 102a are mounted on a carrier substrate 105. The electrodes 121 each include a first line part extending from the relay substrate 102a to the termination substrate 102b via the waveguide substrate 111, and a second line part extending from the first line part and branched off on the termination substrate 102b. A capacitor 131 and a termination resistor 132 are provided on one branch line part 121Aaa out of branch line parts 121Aaa and 121Aab of the second line part whereas the other branch line part 121Aab is connected to a line of the carrier substrate 105 via a bias resistor 133, passes below the waveguide substrate 111, and extends to a bias adjustment DC electrode on the relay substrate 102a. |
