Cavity optomechanics using microresonators

Transcription

1 Cavity optomechanics using microresonators Stefan Weis 2, Samuel Deleglise 2, Remi Riviere 2, Dr. Olivier Arcizet 2 Georg Anetsberger 2, Johannes Hofer and Emanuel Gavartin 1 Collaborators EPFL-CMI K. Lister J. P. Kotthaus W. Zwerger I. Wilson-Rae A. Marx J. Raedler R. Holtzwarth (Menlo System) Tobias J. Kippenberg 1,2 1) Tenure Track Assistant Professor, EPFL & 2) Independent Max Planck Junior Research Group Leader MPQ, (Division of T. W. Hänsch) College de France, Paris, 18 th January 2010 MP-IJRG ERC StG MC-EXT DFG-NIM GSC MC-IRG/IEF NanoSci-ERA

2 Mechanical Effects of Light Photons carry momentum which leads to radiation pressure In the 16 th century Keppler proposed that radiation pressure is responsible for comet tails pointing away from the sun

3 Mechanical Effects of Light on Atoms 1950: Kastler Effet luminorefrigorifique et luminocalirofique 1970: Ashkin Trapping of Particles in Laser Light 1975 Hänsch and A. Schwalow, Dehmelt and Wineland Cooling gases by laser radiation 1989: Laser Cooling to the Zero Point Energy of Motion (Wineland).. Is it also possible observe radiation pressure effects on mesoscopic system? Bouwmeester group Schwab group Pinard group, Aspelmeyer Studied first by Braginsky, Manukin (1967) Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

4 Principle of parametric motion transduction Radiation pressure determines the ultimate sensitivity of an interferometer P in (ω 0, Q 0 ) P cav (ω m,q m ) Radiation pressure x Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

5 Observation of Radiation Pressure (ω m,q m ) P in (ω 0, Q 0 ) P cav Radiation pressure x MPQ 1983: There is a discernible effect of radiation pressure in a high-finesse cavity with a suspended mirror. Dorsel, Meystre, Walther et al., PRL 51, 1550 (1983) Radiation Pressure Limits Position Sensitivity: Standard Quantum Limit Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

6 Standard Quantum Limit of Motion Detection Caves, Phys. Rev. D (1980) Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

7 Coupling light with mechanical oscillators Virgo Dan Rugar (IBM) Gravitational wave interferometric Weak force detection (IBM, San Jose) Detection (VIRGO) Radiation Pressure Quantum Fluctuations limit Position Sensitivity: Standard Quantum Limit Quantum effects with macroscopic mechanical oscillators?

8 Dynamical Backaction The mutual coupling of optical and mechanical modes was first theoretically studied by V.B. Braginsky, Measurement of Weak Forces (ω m,q m ) (ω 0, Q 0 ) P P cav (τ) P in Radiation pressure x V.B. Braginsky Taylor Expansion yields: Position dependent term Velocity dependent term Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

9 Dynamical Backaction The mutual coupling of optical and mechanical modes was first theoretically studied by V.B. Braginsky, Measurement of Weak Forces (ω m,q m ) (ω 0, Q 0 ) P P cav (τ) P in Radiation pressure x V.B. Braginsky

10 Dynamical Backaction The mutual coupling of optical and mechanical modes was first theoretically studied by V.B. Braginsky, Measurement of Weak Forces (ω m,q m ) LIGO (ω 0, Q 0 ) P P cav (τ) P in Radiation pressure x Position dependent term Velocity dependent term; Amplification: pf Blue detuning Cooling: Red detuning Braginsky, Manukin: Measurement of Weak Forces in Physics Experiments (1977)

11 Structures Fabricated at CMI- EPFL * D. K. Armani, T. J. Kippenberg, S. M. Spillane, K. J. Vahala. Nature 421, (2003). Optical Finesse can exceeds 1 million

12 Optical fiber coupling M. Cai, O.J. Painter, K. J. Vahala. Phys. Rev. Lett. (2002).

13 Optical Microresonators with Giant Photon Lifetimes 1/R taper-microcavity junction exhibits extremely high ideality (coupling losses <0.3%) 40 μm Pin Coupling both to-and-from a 80μm microtoroid on a chip S. M. Spillane, T. J. Kippenberg, O.J. Painter, K. J. Vahala. Phys. Rev. Lett. (2003). T.J. Kippenberg, S.M. Spillane, K.J. Vahala, Optics Letters, (2002).

14 Ultra high Q Physics Narrow Linewidth Laser sources Frequency Combs on a Chip Applications in Science, Technology, Metrology Nonlinear Optics at ultra low power Kippenberg, Spillane, Vahala. Phys. Rev. Lett. (2004). Spillane, Kippenberg, Vahala. Nature, (2002).. Cavity QED strong coupling Del Haye, et al. Nature 2007 Cavity Optomechanics Molecule Sensing Kimble Group Nature (2006), Science (2008) Kippenberg, Vahala Science (2008) Fundamental Research

15 Cavity Optomechanics with Microcavities optical whispering-gallery-mode gallery (WGM) meter mechanical radial-breathing-mode (RBM) oscillator Coupling strength Zero point motion T. J. Kippenberg, H. Rokhsari, T. Carmon, A. Scherer and K.J. Vahala Physical Review Letters 95, Art. No (2005)

16 Optomechanical Coupling Intracavity power Homodyne Detection LO Phase of the Transmitted field -

17 Quantitative Analysis of Noise Spectra Calibration peak Schliesser, Anetsberg, Riviere, Arcizet, Kippenberg NJP, 10,

18 Quantitative Analysis of Noise Spectra Thermorefractive noise caused by temperature fluctuations T,V Schliesser, Anetsberg, Riviere, Arcizet, Kippenberg NJP, 10, (focus issue) V. B. Braginsky, M. L. Gorodetsky, and S. P. Vyatchanin, Thermodynamical fluctuations and photo-thermal shot noise in gravitational wave antennae, Phys. Lett. A 264, 1 10 (1999).

19 Mechanical Modes measured mechanical spectrum zoom on idiid individual peaks mode patterns obtained from finite element modeling

20 Sensitivity of the Displacement Measurement From signal to background one can deduce From signal to background one can deduce that the sensitivity is below the SQL

21 Nano Optomechanics Concept Toroid microcavity: Cornell, PRL 2009 oscillator 50 μm Finesse > 10 6 Linewidth < 1 MHz Armani et al. Nature 421, 925 (2003). Kippenberg et al., APL 85, 6113 (2004) Si Chip Anetsberger, Arcizet, Weig, Unterreithmeyer, Kotthaus,Kippenberg, arxiv: (Nature Physics Dec. 2009) Optomechanical near-field interaction

22 Anetsberger, Arcizet, Weig, Unterreithmeyer, Kotthaus,Kippenberg, arxiv: (Nature Physics Dec. 2009) 2009 High Q SiN nanomechanical beams Courtesy yjannik Meyer (Ulm)

23 Cooling by Dynamical Backaction at MPQ detuned laser induces viscous force on cavity boundary... similar to laser cooling of atoms V.B. Braginsky detuned laser Braginsky, Manukin, Ponderomotive effects of electromagnetic radiation, JETP Letters 52, 986 (1967) Hänsch, Schawlow, Cooling of gases by laser radiation, Opt. Commun.13, 68 (1975) Wineland, Dehmelt, Proposed Δν<ν laser fluorescence spectroscopy on Tl + ion mono-oscillator, Bull APS 20, 637 (1975

24 Demonstration of Backaction MPQ Key Parameters: Mechanical frequency of the cooled mode: 57.8 MHz Dec. 2006: Schliesser, Del'Haye,. Nooshi, Initial temperature 300 K Vahala, Kippenberg, Phys. Rev. Lett. 97 Nov. 2006: Arcizet, Cohadon, Briant, Pinard, Heidmann, Nature 444, 71 Final effective temperature 11 K Nov. 2006: S. Gigan et al., Nature 444, 67 First Demonstration of Radiation Pressure Cooling as First Demonstration of Radiation Pressure Cooling as predicted by Braginky and Dykman

25 Sideband interpretation An oscillating i mirror will cause Doppler upand down-shifted fields. Pow wer Frequency A cavity can create an imbalance due to resonant buildup Excess anti-stokes photons: Cooling Power Frequency Similar mechanism to cavity cooling of atoms and molecules (coherent scattering) V. Vuletic, S. Chu, Phys. Rev. Lett., Vol. 84, No. 17 (2000) P. Maunz, Puppe, Schuster, Syassen, Pinkse, Rempe, Nature (2004)

26 Sideband interpretation An oscillating i mirror will cause Doppler upand down-shifted fields. Pow wer Frequency A cavity can create an imbalance due to resonant buildup Excess Stokes photons: amplification Power Frequency Similar mechanism to cavity cooling of atoms and molecules (coherent scattering) V. Vuletic, S. Chu, Phys. Rev. Lett., Vol. 84, No. 17 (2000) P. Maunz, Puppe, Schuster, Syassen, Pinkse, Rempe, Nature 428, 50 (2004).

27 Recent Experiments in cavity Optomechanics ( ) 2009) IT/LIGO aris UCSB Yale Vienna Paris MPQ/Caltech/EPFL Berkeley/ETHZ JILA, USA Caltech Ghent IMEC, Yale T. J. Kippenberg and K. J. Vahala, "Cavity Opto-Mechanics: Backaction at the Mesoscale," Science, 321, 1172 Oregon

28 Quantum regime of mechanical oscillators Prerequisites to be able observe e.g. zero point motion or quantum back-action of the measurement Imprecision at the zero point motion level Mechanical oscillators in which thermal noise is sufficiently reduced (close to quantum ground state) Difficult! e.g. Science Magazine, A. Cho:

29 Demonstration of Backaction Cooling Physics 2, 40 (2009) y ( ) DOI: /Physics.2.40 F. Marquardt, Girvin, Optomechanics

30 Quantum Limits of Radiation Pressure Cooling Quantum Limits of radiation pressure cooling photon shot noise perspective Spectrum of Photon Number Fluctuations Spectrum of Radiation Pressure Fluctuations Final temperature due to Radiation Pressure Fluctuations I. Wilson-Rae, Nooshi, Zwerger, T.J. Kippenberg, PRL 99, (2007) F. Marquardt, Chen, Clerk, Girvin, PRL 99, (2007)

31 Quantum Limits of Radiation Pressure Cooling Reservoir heating Quantum Backaction Doppler limit ground-state cooling impossible resolved sideband cooling ground-state cooling possible Wilson-Rae, Nooshi, Zwerger, Kippenberg, PRL 99, (2007) Marquardt, Chen, Clerk, Girvin, PRL 99, (2007)

32 Resolved Sideband Cooling Lead to ground state cooling of ions: F. Diedrich, J. C. Bergquist, W. M. Itano, D. J. Wineland, Physical Review Letters 62, 403 (Jan, 1989). D. Wineland, H. Dehmelt, Bulletin of the American Physical Society 20, 637 (1975).

33 Demonstration of Resolved Sideband Cooling A. Schliesser, Rivière, Anetsberger, Arcizet, T.J.Kippenberg, Nature Physics 4, (2008)

34 The challenge of ground state cooling Thermal Bath T bath Dissipation Fluctuation Oscillator Dissipation Fluctuation Laser field Cold damper Wilson-Rae, Nooshi, Zwerger, Kippenberg, PRL 99, (2007) Marquardt, Chen, Clerk, Girvin, PRL 99, (2007) Improving mechanical Q Cryogenics...

35 Anetsberger et. al Nat. Photon. 2, 627 (2008) High Finesse and Mechanical Q factor in one and the same device

36 He4 Buffer gas cooling Taper He-gas Temperature sensor Attocube positioners Characteristics He Buffer gas cooling Estimations ba [ Ω] [ Ω] 2 S 4α hqf = P th cav S Ω m ( ) λ( c n) k BTmΩ m κ 2 T=1.6K, l=1μm, m=10 ng, Wm/2p=20 MHz, F=100,00 Q=50,000, R=40μm Pcav = 210 μw n R k BT = Ωh Ωh Arcizet,Riviere, Schliesser, TJK (Phys. Rev. A ).

37 Cryogenic Cavity MPQ Buffer gas precooling n =600

38 Cryogenic Cavity MPQ Buffer gas precooling Conventional DL: n=59 M. D. LaHaye, O. Buu, B. Camarota, K. C. Schwab, Science 304, 74 (2004). n = 100 (Cleland,Nature 2003) Backaction Cooling Schliesser at al. Nature Physics 2009

39 Approaching the SQL using a cryogenic microresonator Schliesser, et al. Nature Physics (2009) Results are a factor of ca. 5 from SQL -Backaction-Imprecision product only x100 from Heisenberg uncertainty limit

40 Low Temperatures: Two level fluctuators (TLS) [2] Crystalline structure Glassy structure: Different possible conformations 2-level system approximation [1] Thermally activated process Tunelling process [2] [1] Vacher, Courtens, Forêt, PRB (2005) [2] Jäckle, Piché, Huncklinger, J. Non-Crys. Sol (1976) 40

41 Low Temperatures: Two level fluctuators (TLS) [2] [1] Qm=25000 [3] [1] Arcizet, Rivière, Schliesser, Anetsberger, Kippenberg, PRA (2009) [2] U. Bartell et al., J. Phys. (Paris) Colloq. 43, C9 (1982)11 [3] Vacher, Courtens, Forêt, PRB 72, (2005)

42 Optomechanics at Helium 3 Temperatures (600 mk) n phonon ~150 Experiments fulfills are prerequisites to achieve cooling to below n=10 and possess imprecision close to SQL. (O. Arcizet, S. Weis, R. Riviere unpublished) * Samples fabricated at the EPFL-CMI clean room facility by Emanuel Gavartin

43 Evidence for direct phonon absorption (Quantum friction) 2 nd Order radial breathing mode Observation: Driving of mechanical oscillator (pm amplitudes) increases the mechanical Q factor Explanation: Saturation of Two Level Systems due to mechanical oscillator also termed Quantum friction L. G. Remus, M. P. Blencowe, Y. Tanaka Phys. Rev. B 80, (2009)

44 Scientific Goals in cavity Optomechanics Quantum Backaction how Nature enforces the Heisenberg uncertainty Caves PRL45 (1980)... Ground-State Cooling true quantum mechanics of a macroscopic object Analog to: Diedrich et al. PRL, Applied Side: Radiation Pressure Driven Quartz Oscillators Novel form of photonic oscillators for metrology and timekeeping i..

45 Conclusions Sideband d Cooling Low dissipation i optomechanics SQL for Nanomechanics PRL, Dec Nature Physics 4, (2008) Nature Physics, 5, , (2009) Nature Photonics 2, 627 (2008) Nature Physics Dec. (2009) Developed crystalline resonators Future Directions Hofer, arxiv Ground state cooling of a mechanical oscillator Measurement of Zero Point Motion Study of Quantum Friction

46 Acknowledgements Thank you for your attention Prof. T. Hänsch (MPQ) Dr. T. Becker (MPQ, cryostat support) Prof. J. Kotthaus (LMU, clean room access) F. Bürsgens (LMU, clean room access) P. Thoumany (MPQ, cryostat support) K. Predehl (EDFA and ESA support) Prof. M. Forêt (LCVN Montpellier) MP-IJRG ERC StG MC-EXT GSC DFG-NIM MC-IRG/IEF NanoSci-ERA