Ingaas-apd And 1310nm Of Studies Of Single Photon Detection

With the coming of information age, we rely more heavily on cryptography to ensure the security of communication. Today's cryptography technology is very safe, however, with the development of computer, it would be useless more and more easily. A new technique which can't be decrypted is eagerly demanded by the military, diplomacy, commerce, and so on. Quantum communication is based on the quantum mechanics and cryptography, its security is guaranteed by the basic quantum principle-Hersenberg's uncertainty principle and the quantum noncloning principle. So it is highlighted by people more and more. One of the key techniques is the detection of near infrared(1310nm and 1550nm). Because the quantum key is transmitted by one photon, and 1310nm and 1550nm infrared are the lost loss wavelength in fiber. We can detect the visible light now, but it is difficult to detect the near infrared because of its low energy. So the applied single photon detector is concerned by the scientist.In our country research in this field is relatively backward, and no ripple device is realized in this field. In order to achieve the quantum communication in the fiber communication windows, we have done some research about near infrared detection.In this thesis we have analyzed some kinds of single photon detector and their advantage and disadvantage firstly. Then, the key apparatus (InGaAs-APD) and its characteristics have been studied. We have tested the APDs of PerkinElmer, OKI and Photon Company, and got some useful parameters. It shows that the APD in different company have different characteristics, even the same type APD in the same company have different characteristics. We also designed the cooler by semiconductor, used the nature cooling and abandoned the water cooling. It is more convenient tothe QKD system. Finally, we detected the 1310nm photon by passively quenching and gated quenching, and designed the 1310nm photon detector. It is showed in this thesis that temperature is very important to single photon detection, but too low temperature is not good for detection because of afterpulse and the breakdown voltage. We also designed the single photon detector using the transimpedance amplifier, which is different from the conventional method, and provided a new idea to infrared detection.