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Increase of Signal-to-Noise Ratio in Weak Value Measurements

  • C. Byard
  • T. Graham
  • A. Danan
  • L. Vaidman
  • A. N. Jordan
  • P. KwiatEmail author

Abstract

We present a method for improving the signal-to-noise ratio of optical weak measurement techniques by recycling the non-post selected light. We designed a system that allows input photons to cycle through a Sagnac interferometer twice, effectively doubling the detected intensity. A deflection as small as 20 picoradians is discernible. The expected improvement for a shot-noise-limited system is a factor of \(\sqrt{2}\); however, we observed a larger signal-to-noise ratio enhancement (1.73±0.46) which can occur for systems limited by technical noise. [Editor’s note: for a video of the talk given by Prof. Kwiat at the Aharonov-80 conference in 2012 at Chapman University, see quantum.chapman.edu/talk-5.]

Notes

Acknowledgements

This work was supported by Army Research Office “Advanced Quantum Sensing” W911NF-12-1-0237 and the Binational Science Foundation Grant No. 32/08. The authors would like to thank B. Dixon for helpful discussions.

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Copyright information

© Springer-Verlag Italia 2014

Authors and Affiliations

  • C. Byard
    • 1
  • T. Graham
    • 1
  • A. Danan
    • 2
  • L. Vaidman
    • 2
    • 4
  • A. N. Jordan
    • 3
    • 4
  • P. Kwiat
    • 1
    Email author
  1. 1.Department of PhysicsUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  2. 2.Raymond and Beverly Sackler School of Physics and AstronomyTel-Aviv UniversityTel-AvivIsrael
  3. 3.Department of Physics and AstronomyUniversity of RochesterRochesterUSA
  4. 4.Institute for Quantum StudiesChapman UniversityOrangeUSA

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