Development of the polarization tracking scheme for free-space quantum cryptography

Morio Toyoshima, Yoshihisa Takayama, Hiroo Kunimori, Masahiro Takeoka, Mikio Fujiwara, Masahide Sasaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)


Quantum cryptography is a new technique for transmitting quantum information. The information is securely transmitted due to the laws of physics. In such systems, the vehicle that transfers quantum information is a single photon. The problem with using photons is that the transmission distance is limited by the absorption of the photons by the optical fiber along which they pass. The maximum demonstrated range so far is approximately 100 km. Using free-space quantum cryptography between a ground station and a satellite is a possible way of sending quantum information farther than is possible with optical fibers. This is because there is no birefringence effect in the atmosphere. However, there is a complication in that the directions of the polarization basis between the transmitter and the receiver must coincide with each other. This polarization changes because the mobile terminals for free-space transmission continuously change their attitudes. If the transmission protocol is based on polarization, it is necessary to compensate for the change in attitude between the mobile terminals. We are developing a scheme to track the polarization basis between the transceivers. The preliminary result is presented.

Original languageEnglish
Title of host publicationAtmospheric Propagation V
Publication statusPublished - 2008
Externally publishedYes
EventAtmospheric Propagation V - Orlando, FL, United States
Duration: 2008 Mar 182008 Mar 20

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceAtmospheric Propagation V
Country/TerritoryUnited States
CityOrlando, FL


  • Optical communication
  • Polarization tracking
  • Quantum cryptography
  • Quantum key distribution
  • Satellite communication

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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