High-Speed InGaAsP Electroabsorption Modulators: Dependence of the Device Characteristics on the Mesa Design

We present characteristics of InGaAsP electroabsorption modulators with variable length and mesa width. We demonstrate devices with return loss below -10dB, bandwidth above 40GHz and extinction ratio of 10dB/2V. We show that low capacitance is advantageous for high-speed operation even when achieved at the expense of increased series resistance.