A pd digitized avalanche signal extraction system with synchronous correlation sampling

Abstract

A synchronous correlated sampling APD digital avalanche signal extraction system, including a clock signal source, a clock fan-out module, a delay chip, an ADC module, a system control and data processing module, a gating generation module, an APD front-end analog conditioning module, and an ADC module The output of the APD conditioning module is sampled under the delayed synchronous clock, and the peak noise caused by the gating can be automatically offset through the correlation sampling and delay scanning circuit, and the effective photon avalanche signal can be extracted. Compared with the prior art, the present invention can automatically offset the spike noise by means of correlation sampling and time-delay scanning, not only can realize digital extraction of avalanche signal, but also can offset the change of APD output signal caused by environmental temperature drift and gate control change , improve the APD's gating frequency conversion capability, so that the extraction of avalanche signals is stable and reliable, the detection efficiency remains stable, and there is no need for repeated calibration or calibration, which is simple, efficient and stable.

Description

technical field [0001] The invention relates to a single-photon detector applied in the field of quantum communication, and can also be applied to the case of using a gating mode in traditional optical communication based on avalanche diode APD, belonging to the field of single-photon level infrared light intensity detection (G01J) and used in quantum The technical field of secure communication core detectors (H04K), especially relates to an APD digital avalanche signal extraction system with synchronous correlation sampling. Background technique [0002] Near-infrared single photon detection can use InGaAs / InP avalanche diodes (APDs) operating in the gated mode, in particular, including single photon avalanche diodes SPADs, to achieve efficient single photon detection. However, it is extremely difficult to extract the APD avalanche signal in the gated working mode, because the amplitude of the gated signal is relatively large, and a large spike noise signal will be generate...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a synchronous correlated sampling APD digital avalanche signal extraction system to solve the existing avalanche signal extraction technology: not only can not achieve the optimal APD dark count and post-pulse performance, but also when the ambient temperature, gating characteristics (such as amplitude, width, frequency, etc.) changes, and repeated calibration is required, which is inconvenient to use, unstable in performance, and has technical defects such as temperature drift and failure risks

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