Abstract
The semiconductor material system InGaAsP on InP is being increasingly used for waveguide based electro-optic devices such as phase modulators, directional coupler modulators, and switches with the long term goal of opto-electronic monolithic integration. The authors have demonstrated the fabrication of long passive rib waveguides (RWG) with low optical losses (3dB/cm) in this material. Electro-optical light modulation was achieved employing a p-n junction. The linear, quadratic and cubic term of the electro-optic effect could be identified. Design rules for high efficiency modulators are proposed.