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dc.contributor.authorBerry, D.en_US
dc.contributor.authorWiseman, Howarden_US
dc.date.accessioned2017-05-03T11:50:56Z
dc.date.available2017-05-03T11:50:56Z
dc.date.issued2002en_US
dc.date.modified2009-10-12T23:13:09Z
dc.identifier.issn10502947en_US
dc.identifier.doi10.1103/PhysRevA.65.043803en_AU
dc.identifier.urihttp://hdl.handle.net/10072/6957
dc.description.abstractWe analyze the problem of quantum-limited estimation of a stochastically varying phase of a continuous beam (rather than a pulse) of the electromagnetic field. We consider both nonadaptive and adaptive measurements, and both dyne detection (using a local oscillator) and interferometric detection. We take the phase variation to be f?=sqrt[?]?(t), where ?(t) is d-correlated Gaussian noise. For a beam of power P, the important dimensionless parameter is N=P/h??, the number of photons per coherence time. For the case of dyne detection, both continuous-wave (cw) coherent beams and cw (broadband) squeezed beams are considered. For a coherent beam a simple feedback scheme gives good results, with a phase variance ?N-1/2/2. This is sqrt[2] times smaller than that achievable by nonadaptive (heterodyne) detection. For a squeezed beam a more accurate feedback scheme gives a variance scaling as N-2/3, compared to N-1/2 for heterodyne detection. For the case of interferometry only a coherent input into one port is considered. The locally optimal feedback scheme is identified, and it is shown to give a variance scaling as N-1/2. It offers a significant improvement over nonadaptive interferometry only for N of order unity.en_US
dc.description.peerreviewedYesen_US
dc.description.publicationstatusYesen_AU
dc.format.extent187962 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglishen_US
dc.language.isoen_AU
dc.publisherAmerican Physical Societyen_US
dc.publisher.placeUSAen_US
dc.publisher.urihttp://prola.aps.org/en_AU
dc.relation.ispartofpagefrom043803.1en_US
dc.relation.ispartofpageto043803.11en_US
dc.relation.ispartofjournalPhysical Review A: Atomic, Molecular and Optical Physicsen_US
dc.relation.ispartofvolume65en_US
dc.subject.fieldofresearchcode240201en_US
dc.titleAdaptive quantum measurements of a continuously varying phase.en_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Peer Reviewed (HERDC)en_US
dc.type.codeC - Journal Articlesen_US
gro.rights.copyrightCopyright 2002 American Physical Society. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal's website for access to the definitive, published version.en_AU
gro.date.issued2002
gro.hasfulltextFull Text


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