Ultra fast quantum key distribution over a 97 km installed telecom fiber with wavelength division multiplexing clock synchronization
Akihiro Tanaka, Mikio Fujiwara, Sae Woo Nam, Yoshihiro Nambu, Seigo Takahashi, Wakako Maeda, K. Yoshino, Shigehito Miki, Burm Baek, Zhen Wang, Akio Tajima, Masahide Sasaki, Akihisa Tomita · Optics Express · 2008
We demonstrated ultra fast BB84 quantum key distribution (QKD) transmission at 625 MHz clock rate through a 97 km field-installed fiber using practical clock synchronization based on wavelength-division multiplexing (WDM). We succeeded in over-one-hour stable key generation at a high sifted key rate of 2.4 kbps and a low quantum bit error rate (QBER) of 2.9%. The asymptotic secure key rate was estimated to be 0.78- 0.82 kbps from the transmission data with the decoy method of average photon numbers 0, 0.15, and 0.4 photons/pulse.