https://doi.org/10.1007/s100530170190
Quantum structures in traveling-wave spontaneous parametric down-conversion
1
Dipartimento di Scienze CC.FF.MM.,Università dell'Insubria, Via Valleggio 16, 22100 Como, Italy
2
Laboratoire de Physique des Lasers, Atomes et Molécules, Université des Sciences et Technologies de Lille,
Bâtiment P5, 59655 Villeneuve d'Ascq Cedex, France
Corresponding author: a enrico.brambilla@uninsubria.it
Received:
5
February
2001
Revised:
11
April
2001
Published online: 15 July 2001
We analyze theoretically spatial structures appearing in the far diffraction zone of the electromagnetic field emitted in the cavityless parametric down-conversion. We investigate in detail the spatial correlation functions of intensity and demonstrate the existence of strong quantum correlations between the regions of the far field symmetrical with respect to the optical axis. Our simplified model allows us to obtain analytical results for some limiting cases. We demonstrate that in the limit of small diffraction and ideal quantum efficiency of photodetection the noise reduction in the photocurrent difference between symmetrical regions in the far diffraction field becomes complete at zero frequency of photocurrent fluctuations.
PACS: 42.50.Dv – Nonclassical field states; squeezed, antibunched, and sub-Poissonian states; operational definitions of the phase of the field; phase measurements / 03.67.-a – Quantum information / 42.65.-k – Nonlinear optics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001
