Near-infrared band low-noise free-running single-photon detector

Abstract

The invention discloses a near-infrared band low-noise free-running single-photon detector, and the detector comprises a negative feedback avalanche photodiode (NFAD), a peripheral circuit of the NFAD, a refrigeration box, a discrimination module, a dead time setting module, a temperature adjustment module and an FPGA; The NFAD and the peripheral circuit are respectively connected with the FPGA through the discrimination module and the dead time setting module. The discrimination module is used for converting an avalanche signal into an electrical level signal and transmitting the electrical level signal to the FPGA. The dead time setting module is used for reducing the bias voltage of the NFAD below an avalanche voltage. The NFAD and the peripheral circuit are packaged in the refrigeration box, and the refrigeration box is connected with the FPGA through the temperature adjustment module. According to the scheme of the invention, the detector carries out the deep refrigeration of the NFAD through a Stirling refrigerator, thereby reducing the dark count of the detector. The post-pulse probability of the detector is effectively inhibited through integrating a single thin resistor in a detector part and setting the dead time after each detection event.

Description

technical field [0001] The invention relates to the technical field of single-photon detection, in particular to a near-infrared band ultra-low noise free-running single-photon detector. Background technique [0002] Single photon detectors in the near-infrared band are essential tools for ultra-weak light detection in this band, and are widely used in quantum communication, quantum information science, optical time domain reflectometer, single-photon radar and other fields. According to the arrival time of the single photon signal, it is divided into a gated mode and a free running mode. When the single photon signal is periodic or its arrival time is known, the gated working mode can be used. When the single-photon signal is aperiodic and the arrival time cannot be accurately known, the single-photon detector must work in a free-running mode. [0003] Currently, free-running single-photon detectors in the near-infrared band mainly include superconducting single-photon det...

AI Technical Summary

Problems solved by technology

However, existing avalanche photodiode free-running single-photon detectors are difficult to use in practical applications because of the huge noise (including dark count and afterpulse)

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