Feasibility of free space quantum key distribution with coherent polarization states
Dominique Elser, Tim J. Bartley, Bettina Heim, Christoffer Wittmann, Сыч Денис Васильевич, Gerd Leuchs · New Journal of Physics · 2009
We demonstrate for the first time the feasibility of free space quantum key distribution with continuous variables under real atmospheric conditions. More specifically, we transmit coherent polarization states over a 100 m free space channel on the roof of our institute's building. In our scheme, signal and local oscillator (LO) are combined in a single spatial mode, which auto-compensates atmospheric fluctuations and results in an excellent interference. Furthermore, the LO acts as a spatial and spectral filter, thus allowing unrestrained daylight operation.