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

Abstract

The invention discloses a method for dynamically adjusting defector drift in a quantum key distribution system. The method comprises the following steps: reading the photon count and the systematic error rate of a single-photon detector in real time to dynamically calculate detection efficiency, in order to monitor the change of the detection efficiency of the single-photon detector in the working process in real time; performing ex-factory parameter calibration on the single-photon detector, calibrating the detection efficiency, and at the set detection efficiency, recording dark count Tc at corresponding detection efficiency without light input and a detection photon count draw value Tf in case of quantum light input; and if the fluctuation of the Tf exceeds a set threshold delta T, starting a self-calibration process. The invention also discloses a device for dynamically adjusting defector drift in the quantum key distribution system. According to the method and the device for dynamically adjusting defector drift in the quantum key distribution system, the defector drift is dynamically adjusted to enable the detector to return a stable operating state, and therefore, the influence of environmental change on the system is overcome.

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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