56 Gbps high speed Ge electro absorption modulator

A high-speed evanescent-coupled Ge waveguide electro-absorption modulator (EAM) with simple fabrication processes was realized on a silicon-on-insulator platform with a 220 nm top Si layer. Selectively grown Ge with a triangle shape was directly used for Ge waveguides of the EAM. An asymmetric p-i-n