Theoretical investigation of a low-voltage Ge/SiGe multiple quantum wells optical modulator operating at 1310 nm integrated with Si₃N₄ waveguides

We report on the design and simulation using 3D-FDTD simulation of Si3N4-integrated Ge/SiGe multiple quantum wells (MQWs) optical modulators at the optical wavelength of 1310 nm. The effect of fabrication tolerance and wavelength dependence on the optical coupling performance between the Si3N4 waveguide and the Ge/SiGe MQWs structure as well as the optical modulation performance are reported. The results show that Si3N4-waveguide-integrated Ge/SiGe MQWs optical modulators can attain several key performance requirements in terms of extinction ratio, insertion loss, driving voltage, and fabrication variations with a compact footprint favorable for short-range optical interconnect applications.