Reactive Cavity Optical Force on Microdisk-Coupled Nanomechanical Beam Waveguides

TLDR

We demonstrate spectrally tuned dispersive and reactive optical force in a cavity optomechanics system comprising a microdisk and a vibrating nanomechanical beam waveguide. The waveguide coupled to the microdisk serves as a bosonic dissipation channel whose motion modulates the cavity’s damping rate, enabling the observed spectrally tuned forces. A reactive optical force arises in addition to the normal dispersive force, is absent at zero detuning, shows asymmetric behavior with a maximum at red‑detuned offset, and points to new avenues in cavity optomechanics.

Abstract

We demonstrate spectrally tuned dispersive and reactive optical force in a cavity optomechanics system that comprises a microdisk and a vibrating nanomechanical beam waveguide. The waveguide coupled to the microdisk acts as a bosonic dissipation channel and its motion modulates the cavity's damping rate. As a result a reactive optical force arises in addition to the normal dispersive force. The cavity enhanced force is not observed at zero detuning but shows asymmetric behavior with a maximum at red-detuned offset. Such reactive cavity backaction force points to new avenues in cavity optomechanics.