Sm. Barnett et al., Equivalence of a lossless beam splitter and a nondegenerate parametric amplifier in conditional measurements, OPT COMMUN, 172(1-6), 1999, pp. 55-57
Ban [Opt, Commun. 143 (1997) 225] demonstrated an equivalence between a los
sless beam splitter with one of the output modes in the vacuum state and a
nondegenerate parametric amplifier with a vacuum input. We show that this e
quivalence can be extended to apply to all states. (C) 1999 Elsevier Scienc
e B.V. All rights reserved.