Figure 9
From: Automated verification of countermeasure against detector-control attack in quantum key distribution
Control of SPD within 100 μs long blinding pulses applied at 20 Hz rate. (a) Click probability versus trigger pulse energy E. Click probabilities under cw blinding are shown for comparison. The probabilities are measured over 103 pulses. (b) The blinding and trigger pulses, the latter being of 240 ps FWHM and applied 50 μs after the start of the blinding pulse. (c) Detector output at \(P = 309\text{ nW}\) and \(E = 10^{-15}\text{ J}\). This trigger pulse never causes a click. (d) The trigger pulse energy is increased by 3 dB to \(2 \times 10^{-15}\text{ J}\). It always causes a click