An InP-Based Dual-Depletion-Region Electroabsorption Modulator with Low Capacitance and Predicted High Bandwidth

A novel dual-depletion-region electroabsorption modulator (DDR-EAM) based on InP at 1550 nm is fabricated. The measured capacitance and extinction ratio of the DDR-EAM reveal that the dual depletion region structure can reduce the device capacitance significantly without any degradation of extinction ratio. Moreover, the bandwidth of the DDR-EAM predicted by using an equivalent circuit model is larger than twice the bandwidth of the conventional lumped-electrode EAM (L-EAM).