title: Polarization-independent, differential-phase-shift, quantum-key distribution system using upconversion detectors.
abstract: We propose and demonstrate a polarization-independent, differential-phase-shift, quantum-key distribution system with upconversion detectors. Even though the detectors have polarization dependency, use of alternative polarization modulation and a two-bit delay interferometer achieves polarization-insensitive operation. In an experiment, sifted key bits were polarization-independently generated over 50 km fiber.
authors.affiliation: Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Iwai
authors.forename: Toshimori
authors.initials: T
authors.lastname: Honjo
authors.forename: Kyo
authors.initials: K
authors.lastname: Inoue
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Kamada
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nishida
authors.forename: Osamu
authors.initials: O
authors.lastname: Tadanaga
authors.forename: Masaki
authors.initials: M
authors.lastname: Asobe