title: Generation and direct detection of broadband mesoscopic polarization-squeezed vacuum.
abstract: Using a traveling-wave optical parametric amplifier with two orthogonally oriented type-I BBO crystals pumped by picosecond pulses, we generate vertically and horizontally polarized squeezed vacuum states within a broad frequency-angular range. Depending on the phase between these states, fluctuations in one or another Stokes parameter are suppressed below the shot-noise limit. Because of the large number of photon pairs produced, no local oscillator is required, and 3 dB squeezing is observed by means of direct detection.
authors.affiliation: Department of Physics, M. V. Lomonosov Moscow State University, Leninskie Gory, 119992 Moscow, Russia.
authors.forename: Timur
authors.initials: T
authors.lastname: Iskhakov
authors.forename: Maria V
authors.initials: MV
authors.lastname: Chekhova
authors.forename: Gerd
authors.initials: G
authors.lastname: Leuchs