In this paper we study a system consisting of two nearly degenerate mechanical modes that couple to a single mode of an optical cavity. We show that this coupling leads to nearly complete (99.5%) hybridization of the two mechanical modes into a bright mode that experiences strong optomechanical interactions and a dark mode that experiences almost no optomechanical interactions. We use this hybridization to transfer energy between the mechanical modes with 40% efficiency.PACS numbers: 42.50. Wk, 42.81.Wg, 42.60.Da, 85.85.+j, Optomechanical systems, in which electromagnetic resonators interact with mechanical resonators, offer a platform for studying a wide range of nonlinear and quantum effects. These systems have been studied in the context of quantum-limited detection of forces and displacements, the production of nonclassical states of light, synchronization and chaotic dynamics, and tests of quantum mechanics with massive degrees of freedom. [1] Optomechanical systems are usually modeled as a single optical mode that is parametrically coupled to a single mechanical mode. This simple model accurately describes many experiments; however, real devices invariably consist of multiple optical and mechanical modes. The presence of multiple modes can provide important capabilities, including new types of optomechanical interactions, robust means for detecting quantum effects, and the ability to transfer quantum states between different systems. [2][3][4][5][6][7][8][9][10][11][12][13] One important class of multimode optomechanical systems consists of devices in which a single optical mode couples to multiple mechanical modes. This situation arises naturally when an optomechanical device with wellseparated optical resonances is driven by a single laser beam. Within the usual weak-coupling description of optomechanics the undriven optical modes are irrelevant, and only the driven mode needs to be considered. [14][15][16] Mechanical modes, on the other hand, cannot be ignored just because they are not driven. This is because any optical mode can be detuned (to some degree) by the displacement of any of the devices' mechanical modes. As a result the effective Hamiltonian for such a device will involve one optical mode coupled to many mechanical modes.In such a system, the motion of a given mechanical mode will modulate the intracavity optical field, which will in turn drive the other mechanical modes. This can be thought of as an optically mediated coupling between the mechanical modes. This intermode coupling can be neglected for mechanical modes whose resonance frequencies are well separated. However, mechanical resonators with * alexey.shkarin@yale.edu some degree of symmetry will have some nearly degenerate modes, and for these modes this coupling can be important.In this paper we demonstrate that the optomechanical coupling between one optical mode and two mechanical modes causes the mechanical modes to nearly fully (99.5%) hybridize into bright and dark states. We then transfer classical mechanical energy betwee...
Molecules are ubiquitous in natural phenomena and man-made products, but their use in quantum optical applications has been hampered by incoherent internal vibrations and other phononic interactions with their environment. We have now succeeded in turning an organic molecule into a coherent two-level quantum system by placing it in an optical microcavity. This allows several unprecedented observations such as 99% extinction of a laser beam by a single molecule, saturation with less than 0.5 photon, and nonclassical generation of few-photon super-bunched light. Furthermore, we demonstrate efficient interaction of the molecule-microcavity system with single photons generated by a second molecule in a distant laboratory. Our achievements pave the way for linear and nonlinear quantum photonic circuits based on organic platforms.
Optomechanical systems couple an electromagnetic cavity to a mechanical resonator which is typically formed from a solid object. The range of phenomena accessible to these systems depends on the properties of the mechanical resonator and on the manner in which it couples to the cavity fields. In both respects, a mechanical resonator formed from superfluid liquid helium offers several appealing features: low electromagnetic absorption, high thermal conductivity, vanishing viscosity, well-understood mechanical loss, and in situ alignment with cryogenic cavities. In addition, it offers degrees of freedom that differ qualitatively from those of a solid. Here, we describe an optomechanical system consisting of a miniature optical cavity filled with superfluid helium. The cavity mirrors define optical and mechanical modes with near-perfect overlap, resulting in an optomechanical coupling rate ~ 3 kHz. This coupling is used to drive the superfluid; it is also used to observe the superfluid's thermal motion, resolving a mean phonon number as low as 11.Light confined in a cavity exerts forces on the components that form the cavity. These forces can excite mechanical vibrations in the cavity components, and these vibrations can alter the propagation of light in the cavity. This interplay between electromagnetic (EM) and mechanical degrees of freedom is the basis of cavity optomechanics. It gives rise to a variety of nonlinear phenomena in both the EM and mechanical domains, and provides means for controlling and sensing EM fields and mechanical oscillators. 1 If the optomechanical interaction is approximately unitary, it can provide access to quantum effects in the optical and mechanical degrees of freedom. 1 Optomechanical systems have been used to observe quantum effects which are remarkable in that they are associated with the motion of massive objects. 2,3,4,5,6,7,8,9,10,11,12 They have also been proposed for use in a range of quantum information and sensing applications. 13,14,15,16,17,18,19,20,21,22 Realizing these goals typically requires strong optomechanical coupling, weak EM and mechanical loss, efficient cooling to cryogenic temperatures, and reduced influence from technical noise.To date, nearly all optomechanical devices have used solid objects as mechanical oscillators.However, liquid oscillators offer potential advantages. A liquid can conformally fill a hollow EM cavity, 23 allowing for near-perfect overlap between the cavity's EM modes and the normal modes of the liquid body's vibrations. In addition, the liquid's composition can be changed in situ, an important feature for applications in fluidic sensing. 24 However, most liquids face two important obstacles to operation in or near the quantum regime: their viscosity results in strong mechanical losses, and they solidify when cooled to cryogenic temperatures. Liquid helium is exceptional in both respects, as it does not solidify under its own vapor pressure and possesses zero viscosity in its purely superfluid state. In addition, liquid He has low EM lo...
We describe measurements of the motional sidebands produced by a mechanical oscillator (with effective mass 43 ng and resonant frequency 705 kHz) that is placed in an optical cavity and cooled close to its quantum ground state. The red and blue sidebands (corresponding to Stokes and anti-Stokes scattering) from a single laser beam are recorded simultaneously via a heterodyne measurement. The oscillator's mean phonon numbern is inferred from the ratio of the sidebands, and reaches a minimum value of 0.84 ± 0.22 (corresponding to a mode temperature T = 28 ± 7 μK). We also infern from the calibrated area of each of the two sidebands, and from the oscillator's total damping. The values ofn inferred from these four methods are in close agreement. The behavior of the sidebands as a function of the oscillator's temperature agrees well with theory that includes the quantum fluctuations of both the cavity field and the mechanical oscillator. Cavity optomechanical systems operating in the quantum regime are expected to play an important role in advancing the control of electromagnetic fields and mechanical oscillators, interfacing disparate quantum systems, detecting gravitational waves, constraining modifications to orthodox quantum mechanics, and testing hypotheses about quantum gravity [1][2][3][4][5][6][7][8][9][10][11]. The utility of optomechanical systems in these areas reflects their particular combination of long relaxation times, unitary coupling to electromagnetic fields in the microwave and near-infrared domains, and access to the quantum behavior of massive objects.Optomechanical experiments have been based primarily on systems in which the mechanical oscillator and the cavity field are prepared in Gaussian states, couple weakly to each other at the quantum level (i.e., the bare optomechanical coupling rate g 0 is much less than the oscillator frequency ω m and the cavity damping rate κ), and are probed via linear measurements of the fields leaving the cavity. (Some optomechanics experiments have demonstrated nonlinear measurements of the cavity fields [12,13], although without resolving non-Gaussian behavior.) Within this paradigm of Gaussian states, weak coupling, and linear measurements, quantum effects can manifest themselves as apparent fluctuations of quantities which, according to classical mechanics, could be noiseless [14]. Depending on the specific type of measurement, these quantum fluctuations may be ascribed to the cavity field, the mechanical oscillator, or both [15,16].One such experiment is a heterodyne measurement of the light leaving an optomechanical cavity that is driven on resonance by a single laser. Classically, the thermal motion of the mechanical oscillator inside the cavity adds modulation sidebands to the laser beam. In the spectrum of the heterodyne signal, the area of these sidebands will be equal, and will be proportional to the oscillator's temperature.In the quantum treatment described in Refs. [15,16] of the same measurement, the heterodyne spectrum arises from four distinct c...
Cavity optomechanics offers powerful methods for controlling optical fields and mechanical motion. A number of proposals have predicted that this control can be extended considerably in devices where multiple cavity modes couple to each other via the motion of a single mechanical oscillator. Here we study the dynamic properties of such a multimode optomechanical device, in which the coupling between cavity modes results from mechanically induced avoided crossings in the cavity's spectrum. Near the avoided crossings we find that the optical spring shows distinct features that arise from the interaction between cavity modes. Precisely at an avoided crossing, we show that the particular form of the optical spring provides a classical analogue of a quantum non-demolition measurement of the intracavity photon number. The mechanical oscillator's Brownian motion, an important source of noise in these measurements, is minimized by operating the device at cryogenic temperature (500 mK).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.