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SUMMARY:MechE Colloquium: The Physics and Applications of high Q optical m
 icrocavities: Cavity Quantum Optomechanics
DTSTART:20201020T121500
DTEND:20201020T131500
DTSTAMP:20260506T020326Z
UID:3bd8250e4d9b618a2c804cfbd48fbcdebc371a4130801ef55f32d62f
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Tobias Kippenberg\, Laboratory of Photonics and Quantum 
 Measurements\, EPFL School of Engineering (STI)\, Institute of Electrical 
 Engineering (IEL) and EPFL School of Basic Sciences (SB)\, Institute of Ph
 ysics (IPHYS)\nIf you would like to attend the talk in BM 5202\, please re
 gister here (on a first-come\, first-served basis). This allows us to limi
 t the number of people in the room and to satisfy contact tracing requirem
 ents.\n\nFor remote attendance: Zoom link\n\n\nAbstract:\nThe mutual coupl
 ing of optical and mechanical degrees of freedom via radiation pressure ha
 s been a subject of interest in the context of quantum limited displacemen
 ts measurements for Gravity Wave detection for many decades(1\, 2). The pi
 oneering work of Braginsky predicted that radiation pressure can give rise
  to dynamical backaction\, which allows cooling and amplification of the i
 nternal mechanical modes of a mirror coupled to an optical cavity and more
 over establishes a fundamental measurement limit via radiation pressure qu
 antum fluctuations. Experimentally these phenomena remained however inacce
 ssible many decades due to the faint nature of the radiation pressure forc
 e. A decade ago\, it was discovered that optical microresonators with ultr
 a high Q\, not only possess ultra high Q optical modes\, but moreover mech
 anical modes that are mutually coupled via radiation pressure(3). The high
  Q of the microresonators\, not only enhances nonlinear phenomena – whic
 h enables for instance optical frequency comb generation(4\, 5) as well as
  temporal soliton formation(6\, 7)– but also enhances the radiation pres
 sure interaction. This has allowed the observation of radiation pressure p
 henomena in an experimental setting and is an underlying principle of the 
 research field of cavity quantum optomechanics(8\, 9).\n\nIn this talk\, I
  will describe a range of optomechanical phenomena that we observed using 
 high Q optical microresonators. Radiation pressure back-action of photons 
 is shown to lead to effective cooling(1\, 2\, 10\, 11) of the mechanical o
 scillator mode using dynamical backaction. Sideband resolved cooling\, com
 bined with cryogenic precooling enables cooling the oscillators such that 
 it resides in the quantum ground state more than 1/3 of its time(12). Incr
 easing the mutual coupling further\, it is possible to observe quantum coh
 erent coupling(12) in which the mechanical and optical mode hybridize and 
 the coupling rate exceeds the mechanical and optical decoherence rate (7).
  This regime enables a range of quantum optical experiments\, including st
 ate transfer from light to mechanics using the phenomenon of optomechanica
 lly induced transparency(13). Moreover\, the optomechanical coupling can b
 e exploited for measuring the position of a nanomechanical oscillator in t
 he timescale of its thermal decoherence(14)\, a basic requirement for prep
 aring its ground-state using feedback as well as (Markovian) quantum feedb
 ack. This regime moreover enables to explore quantum effects due to the ra
 diation pressure interaction\, notably quantum correlations in the light f
 ield that give rise to optical squeezing or sideband asymmetry(15).\n\nThe
  optomechanical toolbox developed in the past decades enables to extend qu
 antum control\, first developed for atoms\, and recently for superconducti
 ng quantum circuits\, to be extended to solid state mechanical oscillators
 . New frontiers that are now possible include for example the generation o
 f non-classical states of motion via post-selection(16)\, mechanical quant
 um squeezing\, or interfaces from radio-frequency to the optical domain(17
 ). Time\, permitting\, recent experiments that probe cavity optomechanics 
 reserved dissipation regime in a microwave opto-mechanical system will be 
 discussed\, which provide a means to realize a cold dissipative reservoir 
 for microwave light(18) a building block for non-reciprocal devices(19).\n
 \nReferences:\n1. V. B. Braginsky\, S. P. Vyatchanin\, Low quantum noise t
 ranquilizer for Fabry-Perot interferometer. Physics Letters A 293\, 228 (F
 eb 4\, 2002).\n2. V. B. Braginsky\, Measurement of Weak Forces in Physics 
 Experiments. (University of Chicago Press\, Chicago\, 1977).\n3. T. J. Kip
 penberg\, H. Rokhsari\, T. Carmon\, A. Scherer\, K. J. Vahala\, Analysis o
 f Radiation-Pressure Induced Mechanical Oscillation of an Optical Microcav
 ity. Physical Review Letters 95\, 033901 (2005).\n4. T. J. Kippenberg\, R.
  Holzwarth\, S. A. Diddams\, Microresonator-based optical frequency combs.
  Science 332\, 555 (Apr 29\, 2011).\n5. P. Del'Haye et al.\, Optical frequ
 ency comb generation from a monolithic microresonator. Nature 450\, 1214 (
 Dec 20\, 2007).\n6. T. Herr et al.\, Temporal solitons in optical microres
 onators. Nature Photonics 8\, 145 (2013).\n7. V. Brasch et al.\, Photonic 
 chip–based optical frequency comb using soliton Cherenkov radiation. Sci
 ence 351\, 357 (2016).\n8. M. Aspelmeyer\, T. J. Kippenberg\, F. Marquardt
 \, Cavity optomechanics. Reviews of Modern Physics 86\, 1391 (2014).\n9. T
 . J. Kippenberg\, K. J. Vahala\, Cavity optomechanics: back-action at the 
 mesoscale. Science 321\, 1172 (Aug 29\, 2008).\n10. A. Schliesser\, P. Del
 'Haye\, N. Nooshi\, K. J. Vahala\, T. J. Kippenberg\, Radiation pressure c
 ooling of a micromechanical oscillator using dynamical backaction. Physica
 l Review Letters 97\, 243905 (Dec 15\, 2006).\n11. A. Schliesser\, R. Rivi
 ère\, G. Anetsberger\, O. Arcizet\, T. J. Kippenberg\, Resolved-sideband 
 cooling of a micromechanical oscillator. Nature Physics 4\, 415 (2008).\n\
 nBio:\nTobias J. Kippenberg is Full Professor in the Institute of Physics 
 and Electrical Engineering at EPFL in Switzerland since 2013 and joined EP
 FL in 2008 as Tenure Track Assistant Professor. Prior to EPFL\, he was Ind
 ependent Max Planck Junior Research group leader at the Max Planck Institu
 te of Quantum Optics in Garching\, Germany. While at the MPQ he demonstrat
 ed 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 gener
 ation of optical frequency combs using high Q micro-resonators\, a princip
 le known now as micro-combs or Kerr combs.\nFor his early contributions in
  these two research fields\, he has been recipient of the EFTF Award for Y
 oung Scientists (2011)\, The Helmholtz Prize in Metrology (2009)\, the EPS
  Fresnel Prize (2009)\, ICO Award (2014)\, Swiss Latsis Prize (2015)\, as 
 well as the Wilhelmy Klung Research Prize in Physics (2015) and the 2018 Z
 EISS Research Award. Moreover\, he is 1st prize recipient of the "8th Euro
 pean Union Contest for Young Scientists" in 1996 and is listed in the High
 ly Cited Researchers List of 1% most cited Physicists in 2014-2019. He is 
 founder of the startup LIGENTEC SA\, an integrated photonics foundry.
LOCATION:BM 5202 https://plan.epfl.ch/?room==BM%205202
STATUS:CONFIRMED
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