Selectively-undercut traveling-wave electroabsorption modulators incorporating a p-InGaAs contact layer.

A novel fabrication process has been developed for fabricating undercut-etched electroabsorption modulators that are compatible with tunable lasers. This process allows for the incorporation of highly doped p-type InGaAs above the upper cladding as an ohmic contact layer. The EAM demonstrates significant improvement in the microwave performance with little effect on modulation efficiency due to the undercut etching. This device uses a traveling wave electrode design with an integrated, matched termination resistor to demonstrate a 34 GHz 3-dB bandwidth for a 600 microm long modulator.