Abstract
Coupling between mechanical and optical degrees of freedom is strongly enhanced by using subwavelength optical mode profiles. We realize an optomechanical system based on a sliced photonic crystal nanobeam, which combines such highly confined optical fields with a low-mass mechanical mode. Analyzing the transduction of motion and effects of radiation pressure we find the system exhibits a photon-phonon coupling rate g0 /2π ≈ 11.5 MHz, exceeding previously reported values by an order of magnitude. We show that the large optomechanical interaction enables detecting thermal motion with detection noise below that at the standard quantum limit, even in broad bandwidth devices, important for both sensor applications as well as measurement-based quantum control.
Highlights
Coupling between mechanical and optical degrees of freedom is strongly enhanced by using subwavelength optical mode profiles
In a cavity optomechanical system, which has an optical resonance frequency ωc that depends on the position of a resonator, both the sensitivity of a displacement measurement and the magnitude of effects caused by radiation pressure forces are governed by two parameters: on the one hand the strength with which acoustic and optical degrees of freedom interact, expressed as the magnitude of the resonator’s influence on the frequency ωc, and on the other hand the cavity linewidth κ
The system we develop is based on a silicon photonic crystal nanobeam, which combines optical confinement with flexural mechanical motion (Fig. 1)
Summary
Coupling between mechanical and optical degrees of freedom is strongly enhanced by using subwavelength optical mode profiles. The resultant coupling between optical and mechanical degrees of freedom gives rise to a radiation pressure force that enables actuation, tuning, damping, and amplification of the resonator, with applications ranging from classical information processing to quantum control of macroscopic objects[1,2]. Such control can be established either passively, by employing the intrinsic dynamics of the system[3,4,5], or actively, by using the outcome of displacement measurements[6]. Per photon in the cavity, the effective optomechanical measurement rate[7,8], as well as the radiation-pressure induced alteration of a resonator’s frequency and damping through dynamical backabcettitoenr ,ospctaiclealwciothntgro02l/oκf
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
