Experimental And Theoretical Research Of Quantum Imaging Based On An Entangled Source

Quantum imaging, a novel non-local image method, attracts much attention in physics community after its observation in the1990s. Quantum imaging is a cross hot research of quantum information and imaging, which has a wide application in bioscience, information technology, national defense, and so on. In recent years, the research of quantum imaging for thermal light in visible range has obtained significant breakthrough. In addition, on the one hand the research of quantum imaging attracts some research interest in the direction of the shortwave, such as quantum imaging based on X-ray; on the other hand, quantum imaging with fermion also attracts a lot of attention, such as neutron, electron, etc.Quantum entanglement is a strange phenomenon in quantum systems, namely, the measurement results of a subsystem can’t be independent of measuring parameters of the other subsystems. Two-photon entanglement, for example, no matter how long is the distance of the two photons, they always keep a special relevance. When one is operated and the state changes, the corresponding state of the other one will instantly change. Not only for some basic physics problems, quantum entanglement also has extensive practical applications, such as quantum communication and quantum computing.Spontaneous parametric down conversion (SPDC) is the most commonly used means of preparing entangled two-photon source, which makes use of the second order nonlinear effect. SPDC could produce entangled photon pairs on polarization, angular momentum and time-energy. The process of SPDC satisfies energy and momentum conservation, and the generated two photons have a certain correlation properties in time and space.The spatial resolution of classical optical imaging is limited by the Rayleigh diffraction limit, i.e. the parameters of optical device and used optical resource. Theoretical calculation showed that in the framework of quantum imaging, the spatial resolution of imaging could be N-times of classical optical when using N-photon entangled resource. With the development of ultra-high bright entangled photon resource, multi-photon quantum imaging is possible.In this dissertation, quantum imaging with an entangled two-photon source was studied. The influence of properties of entangled resource and imaging configuration on quantum image was discussed theoretically and experimentally. The main research contents and innovations are as follows:1. The influence of the characteristics of entanglement source on quantum interference imaging is studied. By numerical calculation, we obtain the results of quantum imaging. For the phase matching problem in spontaneous parametric down conversion, two models were put forward and analyzed. In actual quantum imaging experiment, such two models are equivalent.2. The quantum imaging experiment based on type Ⅱ non collinear parametric down conversion is designed, including the preparation of quantum entanglement resource, data acquisition system and the configuration of quantum imaging. The influence of compensation system on two-photon quantum geometric imaging is studied; and also the object-aperture distance on quantum interference; In addition, the effect of pump focusing on quantum geometric imaging is researched.3. The experiment results show that the compensation system has no obvious effect on quantum geometric imaging; With the increase of object-aperture distance, the quality and visibility of quantum interference pattern could be improved obviously; When the pump beam is focused, the spatial distribution of entangled photon pairs will be changed.