Experimental demonstration of Subcarrier Multiplexed Quantum Key Distribution system feasibility

We report our recent advances in the implementation of a BB84 quantum key distribution demonstrator based on subcarrier multiplexing. A thorough description of all the system modules is provided both in the classical and quantum regimes that are supported by experimental results. We demonstrate that maximum multiplexing gain is achieved when low modulation regime is considered thus fully exploiting the quantum multiplexing process.