Document 
Eur. Phys. J. Special Topics 159, 93-99 (2008)
DOI: 10.1140/epjst/e2008-00697-7
Announcing single photons from imperfect sources by means of "interaction-free" measurements
T. Konrad1, A. Scherer2, M. Nock1 and J. Audretsch21 School of Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
2 Fachbereich Physik, Universität Konstanz, Fach M 674, 78457 Konstanz, Germany
Published online: 21 May 2008
Abstract
Interaction-free measurements can indicate the
presence of photo-sensitive objects and even image the objects
without damaging them. Can they also be used to indicate
the presence of a single photon without absorbing it? We
address this question in the context of improving the
efficiency of single-photon sources. In particular, we
interpret a recently proposed method to announce single
photons based on two-photon absorption [Konrad et al.,
Phys. Rev. A 73, 032327 (2006)] in terms of
"interaction-free" measurements.
© EDP Sciences, Springer-Verlag 2008