Monolithic integration of a SiGe/Si modulator and multiple quantum well photodetector for 1.55 μm operation

The monolithic integration of a SiGe/Si rib waveguide modulator and multiple quantum well photodetector prepared by molecular beam epitaxy is achieved. The low dark current of 49.8 nA at −5 V reverse bias is measured and a modulation depth of 90% at 2.8 V modulation bias is obtained. The external quantum efficiency at $\text{λ=1.55\hspace{0.17em}μ}\mathrm{m}$ is estimated to be 18.2%.