Multiplexing C-band quantum key distribution with O-band classical optical communication over common optical fiber at metro access distance

In this paper, we proposed a WDM co-propagation scheme of assigning quantum key distribution (QKD) to C band wavelength and assigning classical optical communication to O band wavelength over common optical fiber at metro access distance. The experimental result shows that QKD can coexist with error-free 10Gbps optical communication over 50 km G652D fiber while the QKD system has the secret key generation speed above 2 kbps, and QKD can coexist with emulated 100GE ER4 transceiver’s signal at 40km with key generation speed above 2kbps.