Didital controlled high precision high stability APD offset voltage circuit

Abstract

An APD offset voltage circuit of digital controlled high accurate and high stable type consists of primary voltage stabilized unit being connected with the secondary one to each other and being a rectification voltage stabilized circuit, the secondary voltage stabilized unit being series voltage stabilized circuit formed by regulation unit, sampling unit, digital controlled unit, comparison unit and amplification unit.

Description

technical field [0001] The invention relates to quantum cryptography communication, in particular to a digitally controlled high-precision and high-stability APD bias voltage circuit required for APD (avalanche photodiode) work in single-photon detection technology. Background technique [0002] Quantum cryptography communication technology is to load the password information on single photon, and the single photon is transmitted in the optical fiber to realize the transmission of password information. Any user who eavesdrops on the single photon information will change the original state of the single photon when the single photon is obtained, so that the The other party of the communication will find that the information has been tapped, and the information will become invalid. In quantum secure communication, single-photon detection technology is one of the key technologies. When a single-photon detector detects a single-photon signal, it is necessary to provide a normal ...

AI Technical Summary

Problems solved by technology

In quantum secure communication, single-photon detection technology is one of the key technologies. When a single-photon detector detects a single-photon signal, it is necessary to provide a normal working bias voltage for the avalanche photodiode. The size of the bias voltage will affect the avalanche photodiode. The amount of noise when detecting and amplifying single-photon signals. The greater the noise, the greater the miscounting, and the worse the performance of the detector. At the same time, the bias voltage is only when the avalanche photodiode can normally detect and amplify the avalanche signal triggered by single-photon. When it is above the critical value, the larger the bias voltage is, the more non-single-photon avalanche signals will be triggered. These false single-photon avalanche signals will also increase the miscount rate of the detector, thereby degrading the performance of the detector. The first effect of these two effects can be improved by increasing the accuracy of the bias voltage, and the second effect can be resolved by increasing the accuracy of the bias voltage; in addition, the stability of the bias voltage will affect the detection and amplification of the avalanche photodiode The size of the noise in the single-photon signal has also become a limiting factor for improving the detector

However, adjusting the bias voltage in an analog way is easy to introduce bias voltage errors caused by human factors, and it is not easy to digitally integrate in single photon detectors.

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