40Gbit/s optical link in 300-mm silicon platform

We demonstrated 40Gbit/s optical link by coupling a silicon (Si) optical modulator to a germanium (Ge) photodetector from two separate photonic chips. The optical modulator was based on carrier depletion in a pn diode integrated in 950-µm long Mach-Zehnder interferometer. The Ge photodetector was a lateral pin diode butt coupled in silicon waveguide. The overall loss limited by the coupling loss (3 grating couplers x ~4-dB) were estimated to be lower than 18-dB. That also included loss of modulator (4.9-dB) and propagation loss (