| 摘要 |
A directional coupler type optical modulator (100) with travelling-wave electrodes includes a first directional coupler region (27), a waveguide wave coupling region (28), a second directional coupler region (29) and a set of noncrossing travelling-wave electrodes (30,31) disposed along the outside of the waveguides. The electrodes (39, 40; 41, 42) of each directional coupler (27; 29) are connected to the travelling-wave electrodes (30, 31) via air-bridges (63, 64; 163, 164). The waveguide structures are of the P-I-N type having a common N-type conducting layer which provides delta-beta operation of the directional coupler, and both cross and bar states are controlled by a single input signal. <IMAGE> |
