Fig. 3: Laser detuning analysis.
From: Gigahertz measurement-device-independent quantum key distribution using directly modulated lasers
a Experimental time-varying spectral detuning Δf between Alice’s and Bob’s free-running DFB lasers. b Computed X-basis QBER arising from phase error as a function of detuning and clock rate (assuming equally spaced time bins), showing that a higher clock rate permits greater spectral detuning without significant QBER increase.
