OPERATIONAL APPROACH FOR RECONSTRUCTION OF QUANTUM DISTRIBUTIONS IN APREAMPLIFIED HOMODYNE-DETECTION SCHEME

We use the operational theory of homodyne detection, introduced by Ban aszek and Wodkiewicz [Phys. Rev. A 55, 3117 (1997)], to express a gene ric quantum phase space quasiprobability distribution (in the sense of Cahill and Glauber) of an electromagnetic field in terms of the photo count moments. We adapt the method of degenerate parametric (pre)ampli fication of a signal, within the operational theory, in order to overc ome the drawback of nonunit efficiency of the detector. Simulations sh ow that as the gain parameter of the amplification is increased, the q uasiprobability distribution goes closer to the original one, even for an efficiency lower than 0.5. We also express the mean value of an ar bitrary observable in terms of the same photocount moments. [S1050-294 7(97)10111-1].