Single-Photon Detection Based On Ingaas/Inp And The Analysis Of Noise

In recent years, single photon detection which is a key technology in the quantum communication becomes more and more important with the development of quantum communication. In addition, single photon detection can also be used in astronomy, biology, physics and other applications, such as quantum computing, laser ranging and faint object imaging for astronomy applications.There are many devices has been used to detect single photon, such as photomultiplier tubes, avalanche photodiodes and superconducting single-photon detector. Among all these devices, InGaAs/InP single photon avalanche photodiodes became the most widely used single photon detection device in near-infrared communication wavelength due to its high performance and reliability. As single photon detection is being used more frequently in various fields, how to improve the detection performance and reduce the noise of single photon detector is the target of this thesis.This paper mainly reports the works about the key technology in quantum communication when I was in Quantum Communication Laboratory. The works is mainly about the theoretical analysis and experiment progress based on InGaAs/InP single photon avalanche photodiodes. Besides, the paper also reports a new way to generate true random number.Firstly, I introduced the basic situation of quantum communication and single photon detector in the first part. Then the second part reports the process of the single photon detection based on the layer structure of the InGaAs/InP single photon avalanche photodiodes. Besides, it also reports the important parameters of single photon detector and three quenching techniques. In the third part of this paper, it reports the single photon detection based on the InGaAs/InP single photon avalanche photodiodes. In this part, we improved the quenching technique and reduced the noise, especially afterpulses. And then we introduced an innovative technique, which use a program running on FPGA, to measure the aterpulsing. At last, I analyzed the results of the experiment and deduced the formulas of noise in photon detection. Also I briefly introduced a technique which can be used to generate random number.