Two-membrane cavity optomechanics

Abstract

We study the optomechanical behaviour of a driven Fabry-Pérot cavity containing two vibrating dielectric membranes. We characterize the cavity mode frequency shift as a function of the twomembrane positions, and report a ∼2.47 gain in the optomechanical coupling strength of the membrane relative motion with respect to the single membrane case. This is achieved when the two membranes are properly positioned to form an inner cavity which is resonant with the driving field. We also show that this two-membrane system has the capability to tune the single-photon optomechanical coupling on demand, and represents a promising platform for implementing cavity optomechanics with distinct oscillators. Such a configuration has the potential to enable cavity optomechanics in the strong single-photon coupling regime, and to study synchronization in optically linked mechanical resonators.

Noise robustness of synchronization of two nanomechanical resonators coupled to the same cavity field

“…Moreover, we focus our numerical study onto a realistic scenario at room temperature, which is the most interesting one for applications, and consider the set of parameters of Ref. [44], that is ω 1 /2π = 235.810 kHz, ω 2 /2π = 236.580 kHz, g 1 /2π = 0.3 Hz, g 2 /2π = 0.28 Hz, γ 1 /2π = 1.64 Hz and γ 2 /2π = 9.37 Hz. We then take as variable parameters the detuning ∆, cavity decay rate κ and the driving rate E, which is equivalent to change the input power P .…”

“…Synchronization measure as a function of the dimensionless driving amplitudeẼ = E/Es, where Es = 10 5 ω1 corresponds to an input power P 5.5 mW in the case of the experimental parameter regime of Ref [44]…”

The sandwich in the middle: using collective effects for stronger optomechanical coupling

“…On the other hand, the optical field can also couple dissimilar mechanical modes, which is useful for synchronizing the mechanical vibrations [4]. Now, Piergentili et al exploit a multimodal optomechanical system to increase the optomechanical coupling strength [5].The paradigmatic case of an optomechanical system consists of a Fabry-Pérot cavity where one of the cavity mirrors is free to move around its equilibrium position. The mechanical motion couples dispersively to the cavity, that is, the cavity frequency is shifted by a displacement of the mechanical elements, leading to the optomechanical couplingwhere ω c and L are the cavity frequency and its length, respectively.…”

“…On the other hand, the optical field can also couple dissimilar mechanical modes, which is useful for synchronizing the mechanical vibrations [4]. Now, Piergentili et al exploit a multimodal optomechanical system to increase the optomechanical coupling strength [5].…”

“…where ω c and L are the cavity frequency and its length, respectively. Piergentili et alʼs work [5] is based on a very successful variation of the paradigmatic Fabry-Pérot optomechanical cavity, where the end mirrors are fixed and a membrane is placed inside the cavity [6]. Even though the cavity length is constant, the optical path length depends on the position of the membrane along the cavity axis.…”