Fig. 4: Impact of fixed receiver basis bias and source intensities.
From: Finite key performance of satellite quantum key distribution under practical constraints
All curves are for source intensities μ1 = 0.71, μ2 = 0.14, μ3 = 0, extraneous count probability pec = 10−7, and intrinsic quantum bit error rate QBERI = 0.005. a Secret key length (SKL) as a function of \({\theta }_{\max }\) for a fixed \({P}_{{\mathsf{X}}}^{B}\) and fixed pulse intensities. For reference, the black solid line represents the optimal SKL maximised over \({P}_{{\mathsf{X}}}^{A}\) and \({P}_{{\mathsf{X}}}^{B}\) with the same fixed intensity values. b Plots of optimised values for \({P}_{{\mathsf{X}}}^{A}\) as a function of \({\theta }_{\max }\) for a fixed basis \({P}_{{\mathsf{X}}}^{B}\) and fixed pulse intensities. The black solid line represents the optimal basis bias \({P}_{{\mathsf{X}}}^{A}\) with the same fixed intensity values.
