Phase-modulated free space quantum key distribution
相位调制自由空间量子密钥分配

We have realized the phase-modulated free space quantum key distribution(QKD) of a distance 12m, based on the unbalanced Mach-Zehnder interferometer. The set up is stable and secure and it is proved that the phase can be used as coding in the free space QKD just like the polarization.