The phase estimation performance of photonic N00N states propagating in an attenuating medium is analyzed. It is shown that the Heisenberg limit is never achieved and that an attenuated separable state of N photons will actually produce a better phase estimate than an equally attenuated N00N state unless the transmittance of the medium is sufficiently high. Thus, for most practical applications with realistic attenuation, N00N-state-based phase estimation actually performs worse than the standard quantum limit. This performance deficit becomes more pronounced as the number of photons in the signal increases.
© 2008 Optical Society of America
Original Manuscript: December 7, 2007
Revised Manuscript: May 13, 2008
Manuscript Accepted: May 23, 2008
Published: July 29, 2008
Gerald Gilbert, Michael Hamrick, and Yaakov S. Weinstein, "Use of maximally entangled N-photon states for practical quantum interferometry," J. Opt. Soc. Am. B 25, 1336-1340 (2008)