A differential-phase-shift quantum key distribution experiment was carried out with a planar light-wave circuit (PLC) Mach–Zehnder interferometer. This scheme has two advantages: it requires no polarization control and has a high repetition frequency, provided that a stable interferometer is available. Stable polarization-insensitive operation was achieved with an interferometer fabricated by PLC technology. Raw key creation at a rate of 3076 bits/s with a 5.0% quantum bit-error rate was achieved over 20 km of fiber. The stability of the PLC interferometer was examined.
© 2004 Optical Society of America
(270.0270) Quantum optics : Quantum optics
T. Honjo, K. Inoue, and H. Takahashi, "Differential-phase-shift quantum key distribution experiment with a planar light-wave circuit Mach-Zehnder interferometer," Opt. Lett. 29, 2797-2799 (2004)