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SUMMARY:Cavity Quantum Optomechanics with Optical Microresonator - Tobias 
 Kippenberg (EPFL\, Switzerland)
DTSTART:20150309T153000Z
DTEND:20150309T170000Z
UID:TALK58303@talks.cam.ac.uk
CONTACT:6270
DESCRIPTION:The mutual coupling of optical and mechanical degrees of freed
 om via radiation pressure has been a subject of interest in the context of
  quantum limited displacements measurements for Gravity Wave detection for
  many decades. The pioneering work of Braginsky predicted that radiation p
 ressure can give rise to dynamical backaction\, which allows cooling and a
 mplification of the internal mechanical modes of a mirror coupled to an op
 tical cavity. Experimentally these phenomena remained however inaccessible
  many decades due to the faint nature of the radiation pressure force. In 
 2005\, it was discovered that optical microresonators with ultra high Q\, 
 not only possess ultra high Q optical modes\, but moreover mechanical mode
 s that are mutually coupled via radiation pressure(1). The high Q of the m
 icroresonators\, not only enhances nonlinear phenomena – which enables f
 or instance optical frequency comb generation(2) as well as temporal solit
 on formation via the Kerr nonlinearity – but also enhances the radiation
  pressure interaction. This has allowed the observation of radiation press
 ure phenomena in an experimental setting and is an underlying key principl
 e of the now fast developing research field of cavity quantum optomechanic
 s(3\, 4).\nIn this talk\, I will describe a range of optomechanical phenom
 ena that we observed using high Q optical microresonators. Radiation press
 ure back-action of photons is shown to lead to effective cooling(5-8) of t
 he mechanical oscillator mode using dynamical backaction. Cooling to the q
 uantum regime is possible using sideband resolved cooling\, with passive o
 f cryogenic precooling to ca. 700 mK\, which enables cooling the oscillato
 rs such that it resides in the quantum ground state more than 1/3 of its t
 ime(9). Increasing the mutual coupling further\, it is possible to observe
  quantum coherent coupling(9) in which the mechanical and optical mode hyb
 ridize and the coupling rate exceeds the mechanical and optical decoherenc
 e rate (7). This regime enables a range of quantum optical experiments\, i
 ncluding state transfer from light to mechanics using the phenomenon of op
 tomechanically induced transparency(10). In addition experiments are descr
 ibed that utilize the optomechanical coupling for highly efficient force m
 easurements using nanomechanical oscillators(11)\, as well as elements ena
 bling switching\, slowing or advancing of radiation(12). The optomechanica
 l toolbox developed in the past years enables to extend quantum control to
  mechanical oscillators. New frontiers that are now possible include the g
 eneration of non-classical states of motion via post-selection(13) as well
  as the use of ground state cooled oscillators to create quantum limited a
 mplifiers that use the damped mechanical oscillator as a engineered reserv
 oir(14).\nReferences:\n1. 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\, 03390
 1 (2005).\n2. T. J. Kippenberg\, R. Holzwarth\, S. A. Diddams\, Microreson
 ator-based optical frequency combs. Science 332\, 555 (Apr 29\, 2011).\n3.
  T. J. Kippenberg\, K. J. Vahala\, Cavity Optomechanics: Backaction at the
  mesoscale. Science 321\, 1172 (2008\, 2008).\n4. M. Aspelmeyer\, T. J. Ki
 ppenberg\, F. M. Marquardt\, Cavity Optomechanics. http://arxiv.org/abs/13
 03.0733\, (2012).\n5. V. B. Braginsky\, S. P. Vyatchanin\, Low quantum noi
 se tranquilizer for Fabry-Perot interferometer. Physics Letters A 293\, 22
 8 (Feb 4\, 2002).\n6. V. B. Braginsky\, Measurement of Weak Forces in Phys
 ics Experiments. (University of Chicago Press\, Chicago\, 1977).\n7. A. Sc
 hliesser\, P. Del'Haye\, N. Nooshi\, K. J. Vahala\, T. J. Kippenberg\, Rad
 iation pressure cooling of a micromechanical oscillator using dynamical ba
 ckaction. Physical Review Letters 97\, 243905 (Dec 15\, 2006).\n8. A. Schl
 iesser\, R. Rivière\, G. Anetsberger\, O. Arcizet\, T. J. Kippenberg\, Re
 solved-sideband cooling of a micromechanical oscillator. Nature Physics 4\
 , 415 (2008).\n9. 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).\n10. S. Weis et al
 .\, Optomechanically induced transparency. Science 330\, 1520 (Dec 10\, 20
 10).\n11. E. Gavartin\, P. Verlot\, T. J. Kippenberg\, A hybrid on-chip op
 tomechanical transducer for ultrasensitive force measurements. Nature nano
 technology 7\, 509 (Aug\, 2012).
LOCATION:Rutherford building\, Seminar Room B
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