Pulsed squeezed vacuum measurements without homodyning -: art. no. 053812

Following a recent theoretical proposal [J. Fiurasek and N. J. Cerf, Phys. Rev. Lett. 93, 063601 (2004)], we experimentally implement a scheme to measure the squeezing and purity of a single-mode squeezed vacuum state without an interferometric homodyne detection. The suggested setup is based on only a tunable beam splitter and a direct single-photon detector to fully characterize the generated Gaussian states. We discuss the experimental implementation of this procedure and compare it to other reference methods. A detailed exploitation of our results highlights some practical limitations of this method. This experimental work is followed by a detailed numerical analysis to derive the conditions required for the procedure to succeed. In particular, it is found that an overall single-photon detection efficiency of about 50% is needed, which is difficult to achieve in the present experiment.