Monolithically integrated, ultrahigh-frequency cavity nano-optoelectromechanical system with on-chip germanium...

We report the first demonstration of a cavity optoelectromechanical system integrated monolithically with a high-efficiency germanium photodetector on a CMOS-compatible platform. Mechanical resonances are recorded from 0.177 to 2.003 GHz with quality factor up to 4810. These monolithically integrated devices have paved the way for a new category of on-chip optoelectronic components that take the advantage of the resonant properties of the mechanical element and enables new applications such as ultracompact microwave oscillators, optomechanical sensors, and phase shifters.