| 摘要 |
<p>Provided is an optical waveguide element module wherein the optical response frequency characteristics can be flattened over a wide band exceeding tens of GHz, even when the impedance of a modulation electrode of an optical waveguide element and the impedance of a transmission line for inputting a modulation signal from outside the optical waveguide element are different from each other, and even when a filter circuit including a capacitor is arranged on a line for inputting the modulation signal into the modulation electrode of the optical waveguide element. The optical waveguide element module is equipped with an optical waveguide element having an optical waveguide (2) formed on a substrate (1), a modulation electrode (3) which modulates light waves propagating in the optical waveguide, a connector (8) connecting an external signal line which inputs the modulation signal to the modulation electrode, and a relay line formed on a relay substrate (7) and which connects the connector and the modulation electrode. The optical waveguide element module is characterised by the relay line being a coplanar line that sandwiches the signal terminal with the earth terminal, by being composed so as to suppress the reflection of the modulation signal in the optical waveguide element module by the continuous or stepwise change in the impedance of the relay line, as well as by the placement of the filter circuit including a capacitor in the middle of the relay line.</p> |
