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Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light

Abstract

Nearly a century after Einstein first predicted the existence of gravitational waves, a global network of Earth-based gravitational wave observatories1,2,3,4 is seeking to directly detect this faint radiation using precision laser interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task. Here, we inject squeezed states to improve the performance of one of the detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) beyond the quantum noise limit, most notably in the frequency region down to 150 Hz, critically important for several astrophysical sources, with no deterioration of performance observed at any frequency. With the injection of squeezed states, this LIGO detector demonstrated the best broadband sensitivity to gravitational waves ever achieved, with important implications for observing the gravitational-wave Universe with unprecedented sensitivity.

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Figure 1: Simplified layout of the H1 interferometer with squeezed vacuum injection.
Figure 2: Strain sensitivity of the H1 detector measured with and without squeezing injection.
Figure 3: Comparison of possible sensitivity curves for Advanced LIGO.

References

  1. Abramovici, A. et al. LIGO: the Laser Interferometer Gravitational-Wave Observatory. Science 256, 325–333 (1992).

    Article  ADS  Google Scholar 

  2. Abbott, B. et al. LIGO: the Laser Interferometer Gravitational-Wave Observatory. Rep. Prog. Phys. 72, 076901 (2009).

    Article  ADS  Google Scholar 

  3. Acernese, F. et al. Virgo status. Classical Quant. Grav. 25, 184001 (2008).

    Article  ADS  Google Scholar 

  4. Grote, H. et al. The GEO 600 Status. Classical Quant. Grav. 27, 084003 (2010).

    Article  ADS  MathSciNet  Google Scholar 

  5. Caves, C. M. Quantum-mechanical radiation-pressure fluctuations in an interferometer. Phys. Rev. Lett. 45, 75–79 (1980).

    Article  ADS  Google Scholar 

  6. Caves, C. M. Quantum-mechanical noise in an interferometer. Phys. Rev. D 23, 1693–1708 (1981).

    Article  ADS  Google Scholar 

  7. Gerry, C. & Knight, P. Introductory Quantum Optics 10–18 (Cambridge Univ. Press, 2005).

  8. Slusher, R. E. et al. Observation of squeezed states generated by four-wave mixing in an optical cavity. Phys. Rev. Lett. 55, 2409–2412 (1985).

    Article  ADS  Google Scholar 

  9. Xiao, M., Wu, L. A. & Kimble, H. J. Precision measurement beyond the shot-noise limit. Phys. Rev. Lett. 59, 278–281 (1987).

    Article  ADS  Google Scholar 

  10. McKenzie, K. et al. Squeezing in the audio gravitational wave detection band. Phys. Rev. Lett. 93, 161105 (2004).

    Article  ADS  Google Scholar 

  11. Vahlbruch, H. et al. Coherent control of vacuum squeezing in the gravitational-wave detection band. Phys. Rev. Lett. 97, 011101 (2006).

    Article  ADS  Google Scholar 

  12. Vahlbruch, H., Chelkowski, S., Danzmann, K. & Schnabel, R. Quantum engineering of squeezed states for quantum communication and metrology. New J. Phys. 9, 371 (2007).

    Article  ADS  Google Scholar 

  13. Goda, K. et al. A quantum-enhanced prototype gravitational-wave detector. Nature Phys. 4, 472–476 (2008).

    Article  ADS  Google Scholar 

  14. Abadie, J. et al. A gravitational wave observatory operating beyond the quantum shot-noise limit. Nature Phys. 7, 962–965 (2011).

    Article  ADS  Google Scholar 

  15. Harry, G. M. et al. Advanced LIGO: the next generation of gravitational wave detectors. Classical Quant. Grav. 27, 084006 (2010).

    Article  ADS  MathSciNet  Google Scholar 

  16. Fricke, T. et al. DC readout experiment in enhanced LIGO. Classical Quant. Grav. 29, 065005 (2012).

    Article  ADS  Google Scholar 

  17. Chua, S. et al. Backscatter tolerant squeezed light source for advanced gravitational-wave detectors. Opt. Lett. 36, 4680–4682 (2011).

    Article  ADS  Google Scholar 

  18. Stefszky, M. S. et al. Balanced homodyne detection of optical quantum states at audio-band frequencies and below. Classical Quant. Grav. 29, 145015 (2012).

    Article  ADS  Google Scholar 

  19. Abadie, J. et al. Search for gravitational waves from low mass compact binary coalescence in LIGO's sixth science run and Virgo's science runs 2 and 3. Phys. Rev. D 85, 082002 (2012).

    Article  ADS  Google Scholar 

  20. Evans, M., Barsotti, L. & Fritschel, P. A general approach to optomechanical parametric instabilities. Phys. Lett. A 374, 665–671 (2009).

    Article  ADS  Google Scholar 

  21. Takeno, Y. et al. Observation of –9 dB quadrature squeezing with improvement of phase stability in homodyne measurement. Opt. Express 15, 4321–4327 (2007).

    Article  ADS  Google Scholar 

  22. Franzen, A., Hage, B., DiGuglielmo, J., Fiurášek, J. & Schnabel, R. Experimental demonstration of continuous variable purification of squeezed states. Phys. Rev. Lett. 97, 150505 (2006).

    Article  ADS  Google Scholar 

  23. Yonezawa, H. et al. Quantum-enhanced optical phase tracking. Science 337, 1514–1517 (2012).

    Article  ADS  MathSciNet  Google Scholar 

  24. Schnabel, R., Mavalvala, N., McClelland, D. E. & Lam, P. K. Quantum metrology for gravitational wave astronomy. Nature Commun. 1, 121 (2010).

    Article  ADS  Google Scholar 

  25. McClelland, D. E., Mavalvala, N., Chen, Y. & Schnabel, R. Advanced interferometry, quantum optics and optomechanics in gravitational wave detectors. Laser Photon. Rev. 5, 677–696 (2011).

    Google Scholar 

  26. Kimble, H. J., Levin, Y., Matsko, A. B., Thorne, K. S. & Vyatchanin, S. P. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics. Phys. Rev. D 65, 022002 (2001).

    Article  ADS  Google Scholar 

  27. Abbott, B. P. et al. Searches for gravitational waves from known pulsars with science run 5 LIGO data. Astrophys. J. 713, 671–685 (2010).

    Article  ADS  Google Scholar 

  28. Hinderer, T., Lackey, B. D., Lang, R. N. & Read, J. S. Tidal deformability of neutron stars with realistic equations of state and their gravitational wave signatures in binary inspiral. Phys. Rev. D 81, 123016 (2010).

    Article  ADS  Google Scholar 

  29. Vines, J. & Flanagan, E. E. Post-1-Newtonian tidal effects in the gravitational waveform from binary inspirals. Phys. Rev. D 83, 084051 (2011).

    Article  ADS  Google Scholar 

  30. Bauswein, A. & Janka, H. T. Measuring neutron-star properties via gravitational waves from neutron-star mergers. Phys. Rev. Lett. 108, 011101 (2012).

    Article  ADS  Google Scholar 

  31. Abbott, B. et al. Observation of a kilogram-scale oscillator near its quantum ground state. New J. Phys. 11, 073032 (2009).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

The authors acknowledge support from the United States National Science Foundation for the construction and operation of the LIGO Laboratory, and the Science and Technology Facilities Council of the United Kingdom, the Max-Planck-Society and the State of Niedersachsen/Germany for supporting the construction and operation of the GEO600 detector. The authors also acknowledge support for the research, by these agencies and by the Australian Research Council, the International Science Linkages programme of the Commonwealth of Australia, the Council of Scientific and Industrial Research of India, the Istituto Nazionale di Fisica Nucleare of Italy, the Spanish Ministerio de Economía y Competitividad, the Conselleria d'Economia, Hisenda i Innovació of the Govern de les Illes Balears, the Royal Society, the Scottish Funding Council, the Scottish Universities Physics Alliance, The National Aeronautics and Space Administration, the National Research Foundation of Korea, Industry Canada and the Province of Ontario through the Ministry of Economic Development and Innovation, the National Science and Engineering Research Council Canada, the Carnegie Trust, the Leverhulme Trust, the David and Lucile Packard Foundation, the Research Corporation and the Alfred P. Sloan Foundation.

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Contributions

The activities of the LIGO Scientific Collaboration (LSC) include modelling astrophysical sources of gravitational waves, setting sensitivity requirements for observatories, designing, building and running observatories, carrying out research and development of new techniques to increase the sensitivity of these observatories, and performing searches for astrophysical signals contained in the data. S. Dwyer, S. Chua, L. Barsotti and D. Sigg were the leading scientists on this experiment, but a number of LSC members contributed directly to its success. M. Stefszky, A. Khalaidovski, M. Factourovich and C. Mow-Lowry assisted with the development of the squeezed vacuum source under the leadership of N. Mavalvala, D. McClelland and R. Schnabel. K. Kawabe supervised the integration of the squeezed vacuum source into the LIGO interferometer, with invaluable support from M. Landry and the LIGO Hanford Observatory staff. N. Smith-Lefebvre, M. Evans, R. Schofield and C. Vorvick kept the LIGO interferometer at its peak sensitivity and supported the integration of the squeezed vacuum source, with contributions from G. Meadors and D. Gustafson. The initial manuscript was written by L. Barsotti, N. Mavalvala, D. Sigg and D. McClelland. The LSC review of the manuscript was organized by S. Whitcomb. All authors approved the final version of the manuscript.

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Correspondence to L. Barsotti.

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Aasi, J., Abadie, J., Abbott, B. et al. Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light. Nature Photon 7, 613–619 (2013). https://doi.org/10.1038/nphoton.2013.177

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