Theoretical Research And Experimental Detection On The Polarization Of A Photon

In combination with the modern application background of the detection technology, the requirement of long range and high accuracy are put forward for target detection. In addition, it is a hotspot of research to recognize the material of targets in the distance. It can improve the ability to recognize the camouflage target by using the polarization information of the target reflection laser, by which can effectively distinguish the manmade targets from the natural targets. Under the circumstances of long range, the echo of the target is weakened to separated photons, so laser polarization information of photon level is much different from traditional polarization on theories and actual detecting systems. This article does some studies on the problem of polarization information of long-rang weak signal echo in the field of target recognition. In the theoretical research of photon polarization, based on the principle of interaction between atom and photon, the process of photon scattering is treated as the absorption process and the radiation process, and the relationship among the polarization direction of output photon, atomic species and the polarization direction of incident photon is discussed. At the same time, the theoretical formula of the interaction between the photon and atom is simplified, and the variation of probability distribution of the output photon’s polarization direction with the value and the direction of the transition dipole moment of atom is discussed. In addition, the specific theoretical formula of hydrogen atom is derived, and the relationship between the polarization direction of output photon and the polarization direction of incident photon is analyzed in this article. In the experimental research of photon polarization detection, a method to obtain the polarization information based on Gm-APD photon detection is designed, and some experimental tests on this detection system is made. Intensity information is obtained using the number of avalanche of Gm-APD. In this article the response of each Gm-APD in the polarization detection system has been discussed. According to the experimental results, the echo signal is sensitive to the polarization direction of incident photon, and the polarization properties basically corresponds to the Malus law, but there are some displacement between theoretical value and experimental value. This article also do some error analysis to the polarization detection system. Finally, the polarization properties of photon is analyzed when the target is paperboard and aluminium plate.