The possible applications cover a broad range of phenomena: the precise sensing of ultra-weak mechanical forces in nanoscopic systems, the sensing and metrology in quantum systems, the detection of weak signals within the microwave and THz, all the way to the more uncharted. The possible applications cover a broad range of phenomena: the precise sensing of ultra-weak mechanical forces in nanoscopic systems, the sensing and metrology in quantum systems, the detection of weak signals within the microwave and THz, all the way to the more uncharted. An optomechanical amplifier that uses phase-sensitive gain to boost gravitational-wave signals below the standard quantum limit, targeting the radiation-pressure-dominated low-frequency band. Gravitational-wave detectors face a fundamental quantum trade-off: reducing shot noise (by increasing laser. The unidirectional amplification of signals is of great importance in signal processing and communication. We propose a hybrid optomechanical system to achieve directional amplification between light fields with different frequencies, where three cavities are coupled to a common mechanical. Here, we experimentally demonstrate a reconfigurable non-reciprocal device with alternative functions as either a circulator or a directional amplifier via optomechanically induced coherent photon–phonon conversion or gain. The demonstrated device exhibits considerable flexibility and offers. Optomechanics as a branch of physics allows to control the motion of mechanical systems through interaction with light. Our amplifier, implemented in a two-cavity microwave optomechanical device, shows.