Polarization-independent, differential-phase-shift, quantum-key distribution system using upconversion detectors
Yuki Iwai, Toshimori Honjo, Kyo Inoue, Hidehiko Kamada, Y. Nishida, Osamu Tadanaga, Masaki Asobe · Optics Letters · 2009
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.