Optics and Spectroscopy

, Volume 103, Issue 1, pp 76–81 | Cite as

Bit threshold optimization for multiphoton communication in lossy channels

  • V. C. Usenko
  • M. G. A. Paris
Quantum Optics and Quantum Cryptography


We address M-ary communication channels based on entangled two-mode states of radiation in the presence of losses. In particular we focus on channels build by two-mode coherently-correlated (TMC) or twin-beam (TWB) states. Optimized bit discrimination thresholds, as well as the corresponding maximized mutual information, are explicitly evaluated as a function of beam intensities and loss parameters for binary and quaternary alphabets. The evolution of the two entangled support states in lossy channels is analyzed and the joint photon number distribution is evaluated, showing that the beam statistics (either sub-Poissonian for TMC or super-Poissonian for TWB) is not altered by channel losses. The effects of losses on the channel security is discussed.

PACS numbers



Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, Rev. Mod. Phys. 74, 145 (2002); quant-ph/0101098.CrossRefADSGoogle Scholar
  2. 2.
    C. H. Bennett and G. Brassard, in Proceedings of the IEEE International Conference on Computers, Systems and Signal Processing, Bangalore, India (IEEE, New York, 1984), pp. 175–179.Google Scholar
  3. 3.
    A. Ekert, Phys. Rev. Lett. 67, 661 (1991).zbMATHCrossRefADSMathSciNetGoogle Scholar
  4. 4.
    W. Tittel and G. Weihs, Quantum. Inf. Comp. 1(2), 3 (2001); quant-ph/0107156.Google Scholar
  5. 5.
    L. Mandel and E. Wolf, Optical Coherence and Quantum Optics (Cambridge Univ. Press, 1995), pp. 816–827Google Scholar
  6. 6.
    S. L. Braunstein and P. van Loock, Rev. Mod. Phys. 77, 513 (2004); quant-ph/0410100.CrossRefADSGoogle Scholar
  7. 7.
    D. F. Walls and G. J. Milburn, in Quantum Optics (Springer, New York, 1995), pp. 146–157Google Scholar
  8. 8.
    M. Vasilyev, S.-K. Choi, P. Kumar, and G. M. D’Ariano, Phys. Rev. Lett. 84, 2354 (2000).CrossRefADSGoogle Scholar
  9. 9.
    J. Laurat, T. Coudreau, N. Treps, et al., Phys. Rev. Lett. 91, 213601 (2003); quant-ph/03040.Google Scholar
  10. 10.
    J. Perina, Jr., O. Haderka, M. Hamar, and J. Perina, Phys. Rev. A 71, 033815 (2005); quant-ph/0405118.Google Scholar
  11. 11.
    K. Hayasaka, Y. Zhang, and K. Kasai, Opt. Lett. 29, 1665 (2004); quant-ph/0406113.CrossRefADSGoogle Scholar
  12. 12.
    A. Porzio, V. D’Auria, P. Aniello, et al., Opt. Las. Eng. 45, 463 (2007).CrossRefGoogle Scholar
  13. 13.
    V. C. Usenko and B. I. Lev, Phys. Lett. A 3481–2, 17 (2005); quant-ph/0507219.CrossRefADSGoogle Scholar
  14. 14.
    Y. Zhang, K. Kasai, and K. Hayasaka, Opt. Expr. 11, 3592 (2003); quant-ph/0401033.ADSCrossRefGoogle Scholar
  15. 15.
    G. S. Agarwal, Phys. Rev. Lett. 57, 827 (1986).CrossRefADSGoogle Scholar
  16. 16.
    G. S. Agarwal and A. Biswas, J. Opt. B 7, 350 (2005); quant-ph/0501012.MathSciNetADSGoogle Scholar
  17. 17.
    V. C. Usenko and C. V. Usenko, in Proceedings of the Seventh International Conference on Quantum Communication, Measurement and Computing, Glasgow, UK, 2004 (AIP, Boston, 2004), Vol. CP734, p. 319; quant-ph/0407175.Google Scholar
  18. 18.
    S. Olivares, M. G. A. Paris, and A. R. Rossi, Phys. Lett. A 319, 32 (2003).zbMATHCrossRefADSGoogle Scholar
  19. 19.
    A. Serafini, M. G. A. Paris, F. Illuminati, and S. De Siena, J. Opt. B 7, R19 (2005).ADSGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2007

Authors and Affiliations

  • V. C. Usenko
    • 1
  • M. G. A. Paris
    • 2
  1. 1.Institute of Physics of National Academy of ScienceKievUkraine
  2. 2.Dipartimento di FisicaUniversita degli studi di MilanoMilanoItaly

Personalised recommendations