Demonstration of a coexistence scheme between polarization-entangled QKD and classical data channels

Incorporating single photon links used for quantum communication applications like quantum key distribution is a challenging task. Direct contamination from the strong classical signal and induced Raman scattering easily obscures the weak quantum signal. Generating entangled photons in the O-band might allow the coexistence of classical and quantum signals. We present results demonstrating the feasibility of transmitting entangled photons and strong classical communication signals over the same fiber.