Quantum cryptography over 23 km in installed under-lake telecom fibre
Group of Applied Physics,
University of Geneva - 1211 Geneva 4, Switzerland
Accepted: 20 December 1995
A quantum cryptographic channel using a 23 km long installed standard telecom optical cable is reported. The key is encoded in the polarization of very weak laser pulses of average photon number 0.12. The measured error rate is lower than 3.4%. The ability of the system to establish a quantum key at standard telecom wavelength (1300 nm) using installed cables is thus assessed.
PACS: 03.65.Bz – Foundations, theory of measurement, miscellaneous theories (including Aharonov-Bohm effect, Bell inequalities, Berry's phase) / 42.50.-p – Quantum optics / 42.81.Gs – Birefringence, polarization
© EDP Sciences, 1996