Dissipative Optomechanics in a Michelson-Sagnac Interferometer

Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

Figure 1

(a) Topology of the Michelson-Sagnac interferometer. (b) Effective cavity; the properties of $\mathcal{M}$ depend on $M$.

Figure 2

Calculated steady-state occupation number for system II. Throughout this plot, $\Delta ={\omega }_m/2$ and $P_{\mathrm{in}}=10\mathrm{nW}$. Inset: Normalized back action force noise density, illustrating its Fano profile, when ${\omega }_m\approx 0.6{\kappa }_c$ and $\Delta ={\omega }_m/2$; the noise density at $\omega =-{\omega }_m$ is zero.

Figure 3

Full numerical solution for the occupation number $⟨{\widehat{b}}^{†}\widehat{b}⟩$ for (a) system I and (b) system II.