Edinburgh Napier University

  Quantum key distribution (QKD) systems have already attained much attention for providing end-to-end data encryption to the subscribers. However, it is very important that the QKD infrastructure is compatible with the already existing telecommunication networks for a smooth transition and integration with the classical data traffic. Optical fibers and commercially available transceivers are the key element for implementing the quantum network because of the strong dependence of secure key rate on the loss budget and excess noise. In this paper, we report the feasibility of using off-the-shelf telecommunication components to enable high performance Continuous-Variable Quantum Key Distribution (CV-QKD) systems that can yield secure key rates in the range of 100 Mbit/s under practical operating conditions. Classical multilevel phase modulated signals (m-PSK) are evaluated in-terms of secure key generation and transmission distance when they are implemented and detected with classical coherent receiver. The traditional receiver is discussed, aided by the phase noise cancellation based digital signal processing module for detecting the complex quantum signals. Furthermore, we have discussed the compatibility of multiplexers and de-multiplexers for wavelength division multiplexed quantum-to-the-home (QTTH) network.