Dispersive optomechanics: a membrane inside a cavity (original) (raw)
Related papers
Quantum dynamics of a high-finesse optical cavity coupled with a thin semi-transparent membrane
2011
We study the quantum dynamics of the cavity optomechanical system formed by a Fabry-Perot cavity with a thin vibrating membrane at its center. We determine in particular to what extent optical absorption by the membrane hinders reaching a quantum regime for the cavity-membrane system. We show that even though membrane absorption may significantly lower the cavity finesse and also heat the membrane, one can still simultaneously achieve ground state cooling of a vibrational mode of the membrane and stationary optomechanical entanglement with state-of-the-art apparatuses.
Quantum Optomechanics with Engineered Membrane Resonators
Mechanical oscillators coupled to an electromagnetic cavity have emerged as a new frontier in quantum optics. This coupling presents an opportunity for manipulating the quantum state of light, connecting different quantum resources, and ultra-sensitive force detectors. A particular enabling platform utilizes high-stress silicon-nitride membrane resonators. Because of its large tensile stress, the membrane exhibits remarkable mechanical quality factors (Qs) that are even higher than that of single crystalline silicon. The membrane with such high Q combined with robust cryogenic Fabry-Perot cavity enables a variety of quantum optics experiments, such as squeezed light generation. Improving upon these encouraging results requires understanding and engineering the membrane resonators. The membrane dissipation can be classified as the internal loss and the external loss. We are able to manage the internal loss of a hybrid membrane with a curvature map, and control the external loss of a membrane with a phononic crystal (PnC) shield. In this dissertation, I will present our studies and engineering of high-stress membrane mechanics, squeezed light generation, and optomechanical Raman-ratio thermometry with a PnC-isolated membrane.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2011
We propose a theoretical scheme to show the possibility of generating motional nonlinear coherent states and their superposition for an undamped vibrating micromechanical membrane inside an optical cavity. The scheme is based on an intensity-dependent coupling of the membrane to the radiation pressure field. We show that if the cavity field is initially prepared in a Fock state, the motional state of the membrane may evolve from vacuum state to a special type of nonlinear coherent states. By examining the nonclassical properties of the generated state of the membrane, including the quadrature squeezing and the sub-Poissonian statistics, we find that by varying the Lamb-Dicke parameter and the membrane's reflectivity one can effectively control those properties. In addition, the scheme offers the possibility of generating various types of the so-called nonlinear multicomponent Schrödinger cat sates of the membrane. We also examine the effect of the damping of the cavity field on the motional state of the membrane. and entanglement at a macroscopic scale .
Optomechanics with Cavity Polaritons: Dissipative Coupling and Unconventional Bistability
Physical Review Letters, 2014
We study a hybrid system formed from an optomechanical resonator and a cavity mode strongly coupled to an excitonic transition inside a quantum well. We show that due to the mixing of cavity photon and exciton states, the emergent quasiparticles -polaritons -possess coupling to the mechanical mode of both dispersive and dissipative nature. We calculate the occupancies of polariton modes and reveal bistable behavior, which deviates from conventional Kerr nonlinearity or dispersive coupling cases due to the dissipative coupling. The described system serves as a good candidate for future polaritonic devices and solid state quantum information processing.
Cavity-enhanced long-distance coupling of an atomic ensemble to a micromechanical membrane
Physical Review A, 2013
We discuss a hybrid quantum system where a dielectric membrane situated inside an optical cavity is coupled to a distant atomic ensemble trapped in an optical lattice. The coupling is mediated by the exchange of sideband photons of the lattice laser, and is enhanced by the cavity finesse as well as the square root of the number of atoms. In addition to observing coherent dynamics between the two systems, one can also switch on a tailored dissipation by laser cooling the atoms, thereby allowing for sympathetic cooling of the membrane. The resulting cooling scheme does not require resolved sideband conditions for the cavity, which relaxes a constraint present in standard optomechanical cavity cooling. We present a quantum mechanical treatment of this modular open system which takes into account the dominant imperfections, and identify optimal operation points for both coherent dynamics and sympathetic cooling. In particular, we find that ground state cooling of a cryogenically pre-cooled membrane is possible for realistic parameters.
Cavity optomechanics with sub-wavelength grating mirrors
New Journal of Physics, 2012
We design, fabricate and study a novel platform for cavity optomechanics: a silicon nitride membrane patterned as a sub-wavelength diffraction grating. Using the grating as one mirror of a Fabry-Perot cavity, we realize an optical finesse of F = 2830 ± 60, corresponding to a grating reflectivity of R = 0.998. The finesse we achieve appears to be within a factor of two of the limit set by material absorption. We study the finesse as a function of wavelength and optical spot size in order to elucidate various optical loss mechanisms. We find that the cavity exhibits birefringence, and establish that it, too, is a source of optical loss. We then characterize the mechanical motion. We observe hundreds of normal modes, and find the fluctuating amplitude of one of them to be very well described by a Boltzmann distribution. By injecting a reddetuned cooling laser, we optically cool all of the modes that we observe. The lowest effective temperature we achieve is T eff ≈ 1 K.
Quantum dynamics of a vibrational mode of a membrane within an optical cavity
2010
Optomechanical systems are a promising candidate for the implementation of quantum interfaces for storing and redistributing quantum information. Here we focus on the case of a high-finesse optical cavity with a thin vibrating semitransparent membrane in the middle. We show that robust and stationary optomechanical entanglement could be achieved in the system, even in the presence of nonnegligible optical absorption in the membrane. We also present some preliminary experimental data showing radiation-pressure induced optical bistability.
Journal of Optics, 2013
We present an experimental study of an optomechanical system formed by a vibrating thin semitransparent membrane within a high-finesse optical cavity. We show that the coupling between the optical cavity modes and the vibrational modes of the membrane can be tuned by varying the membrane position and orientation. In particular we demonstrate a large quadratic dispersive optomechanical coupling in correspondence with avoided crossings between optical cavity modes weakly coupled by scattering at the membrane surface. The experimental results are well explained by a first order perturbation treatment of the cavity eigenmodes.