Method and device for dynamically adjusting detector drift in quantum key distribution system

Abstract

The invention discloses a method for dynamically adjusting detector drift in a quantum key distribution system, which reads the light count of the single-photon detector in real time and dynamically calculates the detection efficiency of the system bit error rate, so as to monitor the working process of the single-photon detector in real time Changes in the detection efficiency; before leaving the factory, single-photon detector parameters are calibrated to calibrate the detection efficiency. Under the set detection efficiency, record the dark number Tc under the corresponding detection efficiency when there is no light input and the number Tc in the case of quantum light input. Detect the average value Tf of light counts; if the fluctuation of Tf exceeds the set threshold ΔT, start the self-calibration process. The invention also discloses a method for dynamically adjusting detector drift in the quantum key distribution system. The invention dynamically adjusts the drift of the detector, makes the detector return to a stable working state, and overcomes the influence of the environment change on the system.

Description

technical field [0001] The invention relates to a method for adjusting detector drift in a quantum key distribution system, in particular to a method and device for dynamically adjusting detector drift in a quantum key distribution system. Background technique [0002] The block diagram of the working principle of the detector in the quantum key distribution system - also known as QKD - is shown in figure 1 As shown, when the detector is factory calibrated, the dark count of the detected APD tube and the VDC and VTH values ​​at each detection efficiency are calibrated in advance, and these values ​​are solidified into the memory. As the detection works, as the ambient temperature changes, the efficiency of the detector will drift. If the environment changes greatly, the detection efficiency will shift a lot. Although we can control the temperature of the detector, the range and effect of temperature control may not meet the requirements. The practice of traditional detecto...

AI Technical Summary

Problems solved by technology

Although we can control the temperature of the detector, the range and effect of temperature control may not meet the requirements

The practice of traditional detectors is to calibrate the parameters of the detection efficiency when leaving the factory, and no longer modify them in the later work process. If the working environment is very different from the environment at the time of calibration, these pre-calibrated parameters will not be suitable.

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