Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1536989 | Optics Communications | 2011 | 4 Pages |
Abstract
Differential-phase-shift (DPS) quantum key distribution (QKD) is one of the QKD protocols, featuring simplicity for practical implementation. It uses a coherent pulse train whose phase should be stable at least within the pulse interval. This paper quantitatively investigates the phase stability required for DPS-QKD systems. The phase stability is characterized by the spectral linewidth of the light source. A theoretical model and experiments are presented, the results of which indicate that the linewidth should be, for example, less than 0.35% of the free-spectral-range of an asymmetric Mach–Zehnder interferometer in a receiver to achieve quantum bit error rate of less than 0.5% due to linewidth broadening of the light source.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
T. Honjo, T. Inoue, K. Inoue,