High bit rate QKD using sideband modulation scheme with active dispersion compensation

Abstract

Major progress in quantum key distribution (QKD) has been realised recently both for free space and fiber implementations [1–3]. For advanced QKD systems over fiber [1,2], information is encoded in the relative phase between delayed pulses or in polarization. Recently, we proposed an alternative approach where optical pulses are weakly modulated to generate spectral domain sidebands about a central peak. The information is encoded by the relative phase between the sidebands and the central peak [4]. In this paper, we propose a modified architecture based on phase encoding with active dispersion compensation at 12.5 GHz that potentially allows the use of a high bit rate clock.