All-optical processing of microwave signals using cavity optomechanics

Abstract

The physics taking place in optomechanical cavities can be used to operate on microwave signals in the optical domain, which belongs to the realm of microwave photonics. Here we review our recent work on the processing of microwave signals via optomechanical cavities built on silicon chips. Using a silicon optomechanical crystal cavity with a mechanical mode in the phonon lasing regime, we show that the generated microwave tone displays a phase noise low enough to be used in practical applications. We also demonstrate frequency conversion of realistic data streams making use of the inherent nonlinear behavior of the cavity. We also discuss how the long-term stability of the resulting optomechanical microwave oscillator can be improved by locking two different mechanical modes and bringing them to the phonon lasing states. These results suggest that ultra-compact optomechanical cavities show potential application in photonics-enabled next-generation wireless networks and satellite communications.