GHz near infrared single-photon detector avalanche signal extraction system

Abstract

A GHz near infrared single-photon detector avalanche signal extraction system is provided; a gate pulse signal generator is loaded on an avalanche diode cathode through a capacitor C1; a bias voltage unit is loaded on the avalanche diode cathode through a resistor R1; the avalanche diode anode is respectively connected with a resistor R2 and a difference amplifier; two output ends of the difference amplifier respectively output two signals with same value and opposite phases, wherein one signal directly enters a beam combiner with no time delay, the other signal enters the beam combiner after a time delay period, and the beam combiner output end outputs an avalanche signal. Compared with the prior art, the system uses the difference amplifier to amplify and split an avalanche signal and a peak signal outputted by the avalanche diode, thus forming two signals with the same value and opposite phases; the difference amplifier has amplified the avalanche signal, so no extra amplifier is needed, thus reducing the path of noises coupling into the avalanche signal, and reducing the system circuit complexity.

Description

technical field [0001] The invention relates to the technical field of optical signal detection, in particular to a GHz near-infrared single photon detector avalanche signal extraction system. Background technique [0002] In the GHz near-infrared single photon detector, there are many ways to extract the avalanche signal, such as figure 1 Shown is one of the common methods. The working process of the circuit is as follows: ①The bias voltage is loaded on the cathode of the avalanche photodiode (APD) through the resistor R1, and the gate pulse signal is loaded on the cathode of the APD through the capacitor C1; R2 output; ③ The output signal is divided into two signals of equal size by the power divider, one signal is directly input to the subtractor without delay, and the other signal is input to the subtractor after a period of delay; ④ Input to the subtractor The two signals in the detector are subtracted, the spike noise is suppressed, and the avalanche signal can be ex...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a GHz near-infrared single photon detector avalanche signal extraction system to solve the problem that the avalanche signal extracted during the single photon detection process in the prior art has a low amplitude and needs to be amplified by an additional amplifier before being output to subsequent processing circuit, a technical defect that increases the complexity of the system circuit

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