Experimental demonstration of passive decoy state quantum key distribution

Passive decoy state quantum key distribution (PDS-QKD) has advantages in high-speed scenarios. We propose a modified model to simulate the PDS-QKD with a weak coherent light source based on Curty's theory [ Opt. Lett. 34 3238 (2009) ]. The modified model can provide better performance in a practical PDS-QKD system. Moreover, we report an experimental demonstration of the PDS-QKD of over 22.0-dB channel loss.