Phase measurements at the theoretical limit

Phys. Rev. A 63, 013813 – Published 12 December 2000
D. W. Berry and H. M. Wiseman


It is well known that the result of any phase measurement on an optical mode made using linear optics has an introduced uncertainty in addition to the intrinsic quantum phase uncertainty of the state of the mode. The best previously published technique [H. M. Wiseman and R. B. Killip, Phys. Rev. A 57, 2169 (1998)] is an adaptive technique that introduces a phase variance that scales as n-1.5, where is the mean photon number of the state. This is far above the minimum intrinsic quantum phase variance of the state, which scales as n-2. It has been shown that a lower limit to the phase variance that is introduced scales as ln()/n2. Here we introduce an adaptive technique that attains this theoretical lower limit.


  • Received 18 February 2000
  • Published 12 December 2000

© 2000 The American Physical Society

Authors & Affiliations

D. W. Berry1 and H. M. Wiseman1,2

  • 1Department of Physics, The University of Queensland, St. Lucia 4072, Australia
  • 2School of Science, Griffith University, Nathan, Brisbane, Queensland 4111, Australia

References (Subscription Required)

Authorization Required


Download & Share

PDF Export Citing Articles (8)



Log In



Article Lookup
Paste a citation or DOI

Enter a citation
  1. Enter a citation to look up or terms to search.

    Ex: "PRL 112 068103", "Phys. Rev. Lett. 112, 068103", "10.1103/PhysRevLett.112.068103"