Fig. 1
Principles of dispersive and dissipative cavity optomechanical acoustic sensing. a, d Conceptual schematics of Fabry–Pérot cavity-based dispersive (a) and dissipative (d) sensors. In a an applied acoustic force drives harmonic oscillation of a movable cavity end-mirror modulating the length and resonance frequency of the cavity. In d the force drives a mechanical element that modulates the decay rate of the cavity. The modulation is monitored via the change in optical transmission (Topt) from the cavity. b, e Cavity transmission in the presence of dispersive and dissipative coupling, respectively. The solid blue curves show the cavity transmission for the initial position of the mechanical element while the red dashed curves show the modified cavity transmission due to displacement of the mechanical element. c, f Amplitude of external-force driven modulation in transmission (ΔTopt) of the cavity optomechanical system for dispersive and dissipative coupling, respectively, versus the detuning Δ of the input laser field from the cavity resonance
