Title: Cavity Quantum Optomechanics
Speaker Name and Affiliation: Prof. Dr. Tobias J. Kippenberg (PhD), EPFL , Switzerland
The mutual coupling of optical and mechanical degrees of freedom via radiation pressure has been a subject of interest in the context of quantum limited displacements measurements for Gravity Wave detection for many decades(1
). Braginsky’s predicted that radiation pressure can give rise to dynamical backaction, which allows cooling and amplification mechanical modes of a mirror. While this effect has only recently been observed in LIGO, experimentally these phenomena remained inaccessible many decades due to the faint nature of the radiation pressure force. With the discovery of optomechanical interactions in high Q optical microresonators(2
) in 2005, and a host of new systems that have emerged since then, it has become possible to study radiation pressure interaction in micro- and nanoscale resonators which has led to the field of cavity quantum optomechanics(3
). The high Q of the microresonators, not only enhances nonlinear phenomena – enabling for instance optical frequency comb generation(5
) on a chip– but also enhances the radiation pressure interaction and is an underlying principle cavity quantum optomechanics. Over the past decade, cavity optomechanics has allowed to extend the quantum control from ions, molecules and atoms, to mechanical oscillators, that can be engineered and coupled to other systems.
In this talk, I will describe a range of optomechanical phenomena that have been observed in our laboratory at EPFL, using high Q optical microresonators. Radiation pressure back-action of photons is shown to lead to effective cooling(1, 6-8) of the mechanical oscillator mode using dynamical backaction. When combined with cryogenic buffer gas precooling using He-3 gas, sideband resolved cooling allows to cool the oscillator, such that it resides in the quantum ground state more than 1/3 of its time(9). Increasing the mutual coupling further, it is possible to observe quantum coherent coupling(9) in which the mechanical and optical mode hybridize. In addition, it is possible to observe the effect of optomechanically induced transparency(10), which can be used in a wide range of optomechanical protocols – both in the classical and quantum domain - , ranging from state transfer from light to mechanics(11), or coherent wavelength conversion between vastly different frequencies(12), to preparing squeezed laser beams for LIGO(13). New frontiers of quantum optomechanics that are now possible, include the generation of non-classical states of motion via post-selection(14) as well as the use of ground state cooled oscillators to create quantum limited amplifiers that use the damped mechanical oscillator as a engineered reservoir(15). In addition, optomechanical systems have recently enabled real time quantum feedback of nanomechanical oscillators(16), which enable to track the oscillators state faster that the influence of environmentally induced thermal decoherence. The optomechanical toolbox developed over the past decade has enabled to extend quantum control to mechanical oscillators.
1. V. B. Braginsky, Measurement of Weak Forces in Physics Experiments. (University of Chicago Press, Chicago, 1977).
2. T. J. Kippenberg, H. Rokhsari, T. Carmon, A. Scherer, K. J. Vahala, Analysis of Radiation-Pressure Induced Mechanical Oscillation of an Optical Microcavity. Physical Review Letters 95, 033901 (2005).
3. T. J. Kippenberg, K. J. Vahala, Cavity optomechanics: back-action at the mesoscale. Science 321, 1172 (Aug 29, 2008).
4. M. Aspelmeyer, T. J. Kippenberg, F. Marquardt, Cavity optomechanics. Reviews of Modern Physics 86, 1391 (2014).
5. T. J. Kippenberg, R. Holzwarth, S. A. Diddams, Microresonator-based optical frequency combs. Science 332, 555 (Apr 29, 2011).
6. V. B. Braginsky, S. P. Vyatchanin, Low quantum noise tranquilizer for Fabry-Perot interferometer. Physics Letters A 293, 228 (Feb 4, 2002).
7. A. Schliesser, P. Del'Haye, N. Nooshi, K. J. Vahala, T. J. Kippenberg, Radiation pressure cooling of a micromechanical oscillator using dynamical backaction. Physical Review Letters 97, 243905 (Dec 15, 2006).
8. A. Schliesser, R. Rivière, G. Anetsberger, O. Arcizet, T. J. Kippenberg, Resolved-sideband cooling of a micromechanical oscillator. Nature Physics 4, 415 (2008).
9. E. Verhagen, S. Deleglise, S. Weis, A. Schliesser, T. J. Kippenberg, Quantum-coherent coupling of a mechanical oscillator to an optical cavity mode. Nature 482, 63 (Feb 2, 2012).
10. S. Weis et al., Optomechanically induced transparency. Science 330, 1520 (Dec 10, 2010).
11. T. A. Palomaki, J. W. Harlow, J. D. Teufel, R. W. Simmonds, K. W. Lehnert, Coherent state transfer between itinerant microwave fields and a mechanical oscillator. Nature 495, 210 (Mar 14, 2013).
12. R. W. andrews et al., Bidirectional and efficient conversion between microwave and optical light Nature Physics 10.1038/NPHYS2911, (2014).
13. J. Qin et al., Classical demonstration of frequency-dependent noise ellipse rotation using optomechanically induced transparency. Physical Review A 89, (2014).
14. C. Galland, N. Sandguard, N. Piro, N. Gisin, T. J. Kippenberg, Heralded single phonon preparation, storage and readout in cavity optomechanics. Physical Review letters (2014).
15. A. Nunnenkamp, V. Sudhir, A. K. Feofanov, A. Roulet, T. J. Kippenberg, Quantum-Limited Amplification and Parametric Instability in the Reversed Dissipation Regime of Cavity Optomechanics. Physical Review Letters 113, (2014).
16. D. J. Wilson et al., Measurement and control of a mechanical oscillator at its thermal decoherence rate. arXiv:1410.6191 (Nature, in press), (2014-10-22, 2014).
Figure: SEM image of a toroid resonator and the optomechanical coupling between the optical and mechanical degree of freedom mediated by radiation pressure.
Tobias J. Kippenberg is since 2013 ordinary Professor in the Institute of Condensed Matter Physics and EE at EPFL in Switzerland and joined EPFL in 2008 as Tenure Track Assistant Professor. Prior to EPFL he was Independent Max Planck Junior Research group leader at the Max Planck Institute of Quantum Optics in Garching in the Division of T.W. Haensch. He obtained his BA at the RWTH Aachen in 1998, his PhD at Caltech in 2004 and Habilitation in Physics at the LMU Munich in 2009.
While at the MPQ he demonstrated radiation pressure cooling of optical micro-resonators, and developed techniques with which mechanical oscillators can be cooled, measured and manipulated in the quantum regime that are now part of the research field of Cavity Quantum Optomechanics. Moreover his group discovered the generation of optical frequency combs using high Q micro-resonators. For his early contributions in these two research fields he has been recipient of the EFTF Award for Young Scientists (2011), The Helmholtz Prize in Metrology (2009) and the EPS Fresnel Prize (2009) and ICO Award (2014) and the Swiss Latsis Prize (2015) as well as the Wilhelmy Klung Research Prize in Physics (2015). Moreover, he is 1st prize winner of the "8th European Union Contest for Young Scientists" in 1996. He has an H-factor of 44 and given more than 160 invited talks.