| 摘要 |
PURPOSE:To execute a modulation at high speed by providing plural divided traveling-wave electrodes along a waveguide and lengthening successively the length of a microwave supply use line, based on a speed difference between a light wave and a microwave. CONSTITUTION:On a substrate 1 on which a waveguide 2 has been formed, plural divided traveling-wave electrodes 3-5 are provided along the waveguide 2. Subsequently, microwave supply use lines 10-12 which have been allowed to branch to plural lines from the same power source 9 are connected to plural traveling-wave electrodes 3-5, respectively. Also, the length of plural lines 10-12 is varied so as to be lengthened successively, based on a speed difference between a light wave and a microwave. That is, by setting suitably the length of the line so as to be lengthened successively, based on the speed difference between the light wave and the microwave, a delay time generated in accordance with the length of the lines 10-12 can be made equal to the time required for a fact that the light wave is propagated from under one electrode to under the next electrode in the waveguide 2. In such a way, the speed difference between the light wave and the microwave is eliminated substantially, and the modulation can be executed at high speed. |
