Abstract
Free-space quantum key distribution (QKD) is expected to realized a global system for QKD based on a network of ground to satellite or satellite to satellite, and thus to extend the distance limit and the utility of QKD method [1]. We repot an experimental demonstration of free-space continuous-variable QKD (CV-QKD). We use a 1.55 μ m-wavelength pulsed diode laser and a pulsed homodyne detector. Advantages of working at 1.55 μ m over working at 0.8 μ m are that Rayleigh scattering in air is smaller and 1.55 μ m is eye safe. The homodyne detector is used to detect a faint light and it is sensitive only to the light that is spatially, temporally, and spectrally matched with the LO light. This means that the LO acts as a narrow filter. Therefore, a homodyne detector is less sensitive to a stray light compared with single-photon detector. In order to make a practical CV-QKD system using pulsed homodyne detection, realization of a stable interferometer is a necessary ingredient.
© 2007 IEEE
PDF ArticleMore Like This
W. T. Buttler, R. J. Hughes, P. G. Kwiat, S. K. Lamoreaux, G. G. Luther, G. L. Morgan, J. E. Nordholt, C. G. Peterson, CM. Simmons, and A. G. White
QWB2 International Quantum Electronics Conference (IQEC) 1998
Bettina Heim, Dominique Elser, Tim Bartley, Metin Sabuncu, Christoffer Wittmann, Denis Sych, Christoph Marquardt, and Gerd Leuchs
LSTuA3 Applications of Lasers for Sensing and Free Space Communications (LS&C) 2010
K. Bencheikh, A. Jankovic, Th. Symul, and J.A. Levenson
QThN4 Quantum Electronics and Laser Science Conference (CLEO:FS) 2001