A high-speed quantum key distribution system was developed with the wavelength-division multiplexing (WDM) technique and dedicated key distillation hardware engines. Two interferometers for encoding and decoding are shared over eight wavelengths to reduce the system’s size, cost, and control complexity. The key distillation engines can process a huge amount of data from the WDM channels by using a 1 Mbit block in real time. We demonstrated a three-channel WDM system that simultaneously uses avalanche photodiodes and superconducting single-photon detectors. We achieved 12 h continuous key generation with a secure key rate of 208 kilobits per second through a 45 km field fiber with 14.5 dB loss.
© 2012 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: September 15, 2011
Manuscript Accepted: November 14, 2011
Published: January 13, 2012
Ken-ichiro Yoshino, Mikio Fujiwara, Akihiro Tanaka, Seigo Takahashi, Yoshihiro Nambu, Akihisa Tomita, Shigehito Miki, Taro Yamashita, Zhen Wang, Masahide Sasaki, and Akio Tajima, "High-speed wavelength-division multiplexing quantum key distribution system," Opt. Lett. 37, 223-225 (2012)