Method for detecting gigahertz single photon with low time jitter and low noise

Abstract

The invention relates to the field of quantum secret communication and weak infrared light detection in the technical field of optical fiber communication, in particular to a method for detecting a gigahertz high-speed near infrared single photon with low time jitter and low noise. A control circuit related to the method consists of a signal detection circuit, a noise suppressing circuit and a signal processing circuit, wherein the noise suppressing circuit is used for extracting an avalanche electric signal by the following steps of: dividing a sine signal of gigahertz into two paths; loading one path serving as a gate signal on an avalanche photoelectric diode; transmitting a response output signal of the avalanche photoelectric diode to a low-pass filter; attenuating the other path of sine signal to an amplitude which is same as that of the response signal of the avalanche photoelectric diode passing through the low-pass filter; and transmitting the other path of sine signal to a balance circuit for balancing with the response signal of the avalanche photoelectric diode passing through the low-pass filter to remove spike noise and extract the avalanche electric signal. In the method, the spike noise is removed in a way of combining low-pass filtering with the balance circuit, so that the avalanche signal is extracted, higher detection efficiency is achieved, and the time jitter is controlled within dozens of picoseconds.

Description

technical field [0001] The invention relates to the field of quantum secure communication and weak infrared light detection in the field of optical fiber communication technology, and in particular to a gigahertz high-speed near-infrared single-photon detection method with low time jitter and low noise. Background technique [0002] Single-photon detection technology is one of many technologies for ultra-sensitive optical signal detection, and it has a very wide range of applications in physics, chemistry, biology and other disciplines as well as engineering applications. In recent years, with the rise of quantum information science and the development of ultrasensitive spectroscopy, single photon detector technology has played an increasingly important role in it. [0003] Among the single-photon detection technologies in many bands, the near-infrared single-photon detection technology has attracted more attention due to its wide application and importance, especially in t...

AI Technical Summary

Problems solved by technology

However, while filtering the noise, the corresponding spectral components of the avalanche signal are also filtered out, which destroys the integrity of the avalanche signal. Multiple filtering will not only reduce the amplitude of the avalanche signal, but also increase the time jitter of the single photon detector.

In laser ranging, the degree of time jitter of the single photon detector directly determines the measurement accuracy of the entire set. The method of using multiple filters has too much time jitter to meet the requirements of ranging.

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