The four wave mixing effects in quantum key distribution based on conventional WDM network

With the escalating applications of the Internet, its security has been an increasingly important issue. Quantum key distribution (QKD) has been studied for the last three decades and is a potential way to safeguard the Internet security. As to make QKD more acceptable in Internet applications, we study how to make it integrated to conventional optical network. In the conventional optical networks, WDM is a typical technique to save the fiber resources. In this paper, we analyze the effects of WDM on quantum signal, especially the four wave mixing (FWM) effects. We also propose an unequally spaced channels scheme to decrease the impact of FWM and demonstrate it in simulation.