Balance-inhibited single-photon detecting circuit modules

Abstract

A circuit module is composed of signal detection circuit, balance-suppression circuit and signal processing circuit. It is featured as sending detected signal to balance-suppression circuit which sends the signal to signal processing circuit, using two completely the same APD driving circuit form signal detection circuit.

Description

technical field [0001] The invention relates to quantum security communication, in particular to a double-APD balanced narrow-gate suppressed APD single-photon detection circuit module to realize near-infrared band single-photon detection. Background technique [0002] Quantum secure communication is based on light quantum communication. Information is loaded on and transmitted by single photons. The unknown quantum state cannot be cloned. Measuring the quantum will change the quantum state, so that it is impossible for eavesdroppers to obtain information without being discovered , so in quantum secure communication, single photon detection plays a very important role. The single-photon detectors used in quantum secure communication systems are mainly avalanche photodiodes (APDs). [0003] In single-photon detection, the APD generally works in the so-called "Geiger mode". In this mode, the bias voltage across the avalanche photodiode is greater than the avalanche voltage, a...

AI Technical Summary

Problems solved by technology

[0004] The existing gate pulse suppression mode usually only adds a gate pulse at one end of the APD. When the gate pulse is relatively narrow, generally below 50ns, the charge and discharge signals of the APD are connected together, and there is no flat area between them. At this time, when photons arrive, The avalanche signal generated by the APD will be superimposed on its charge and discharge signal. Since the avalanche signal is much smaller than the charge and discharge signal, there is no way to identify it. At the same time, the oscillation and overshoot signal caused by the narrow pulse will affect the signal acquisition. ; Therefore, the gate width of the existing gate pulse suppression mode is relatively wide. When the gate pulse is relatively wide, there is a flat area between the charge and discharge signals of the APD. If photons arrive in this flat area, the avalanche signal generated by the APD will It can be detected, but the noise is relatively large, and the detection time accuracy is not accurate enough

Therefore, a dual-APD balanced suppression mode has appeared abroad, but the modules used in the balanced suppression circuit are very complicated and bulky

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