Transmission Line Characterization of Undercut-Ridge Traveling-Wave Electroabsorption Modulators

An experimental analysis of the electrical properties of traveling-wave electroabsorption modulators with undercut waveguides is presented. Modulators of varying ridge widths and amounts of undercut are fabricated and tested to compare characteristic impedance, effective index, microwave loss, and optical bandwidth. We demonstrate effective velocity matching and >40-GHz 3-dB bandwidth for a 400-mum-long device.