Practical point-to-point free-space quantum key distribution over 1/2 km

W. T. Buttler, R. J. Hughes, P. G. Kwiat, S. K. Lamoreaux, G. L. Morgan, J. E. Nordholt, C. G. Peterson

Research output: Contribution to journalConference articlepeer-review


A point-to-point single-photon quantum key distribution (QKD) over a free-space optical path of approximately 475 m through a turbulent medium under daylight conditions is demonstrated. This represents an increase of >1000 times farther than any reported point-to-point demonstration and >6 times farther than the previous folded path daylight demonstration. A passive QKD transmitter and receiver that provides a secure method to secretly communicate with a simple system based on the B92 protocol is described.

Original languageEnglish (US)
Pages (from-to)344-345
Number of pages2
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1999
Externally publishedYes
EventProceedings of the 1999 18th Congress of the International Commission for Optics (ICO XVIII): Optics for the Next Millennium - San Francisco, CA, USA
Duration: Aug 2 1999Aug 6 1999

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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