Figure 6

(a) Comparison of the final key generation rate R between different methods. The solid line (H1) refers to our new scheme, the dashed line (H3) corresponds to the standard three-intensity scheme using HSPS, and the dash-dotted line (W3) represents a conventional three-intensity MDI-QKD using WCS. (b) The ratio between the key generation rates of the new proposed passive scheme and the other two, see the left and right axes respectively.