Experimental investigation of heterodyne quantum key distribution in the S-band or L-band embedded in a commercial C-band DWDM system.

The tolerance of continuous-variable quantum key distribution to co-propagating DWDM channels is investigated. The quantum channel is operated in the S-band or L-band and multiplexed with a commercial C-band DWDM system. The results show that, compared to previously proposed configurations, the number of co-propagating channels can be doubled.

Continuous variable quantum key distribution with a real local oscillator using simultaneous pilot signals.

In this Letter, we propose a novel implementation of continuous variable quantum key distribution that operates with a real local oscillator placed at the receiver site. In addition, pulsing of the continuous wave laser sources is not required, leading to an extraordinary practical and secure setup. It is suitable for arbitrary schemes based on modulated coherent states and heterodyne detection.