Figure 1
From: Automated verification of countermeasure against detector-control attack in quantum key distribution
Setup for testing detector control by bright light. CL, continuous-wave laser (1552Â nm, 40Â mW, Thorlabs SFL1550P); PL, pulsed laser (1552Â nm, Gooch & Housego AA1406); Iso, optical isolator; VOA, programmable variable optical attenuator (OZ Optics DA-100); BS, fiber beamsplitter; PM, optical power meter (Thorlabs PM400 with S155C head); SPD, single-photon detector under test. The pulse generator (Highland Technology P400) drives PL directly and can induce relaxation-limited short laser pulses. The counter (Stanford Research Systems SR620) typically accumulates clicks over 1Â s for each data point