| Quantum theory has been developing and improving since the end of nineteenth Century and it combined with other disciplines development has brought abundant study results.Quantum entanglement is a quantum phenomenon,The most notable feature is that the quantum entanglement system cannot be expressed directly by its subsystems.In view of this special property,quantum entanglement can be applied to many fields.The most representative properties are quantum communication,quantum computer,quantum imaging and quantum illumination.Many problems are difficult to solve in the traditional optical imaging and radar detection.It is urgent to solve the problem of difficult target detection with high interference emission and low signal intensity in the radar detection.The quantum illumination is to solve this problem.We get the detection by using the entangled signal and do correlation measurement at the receiver result.Theoretically,the N photon entangled system can increase the SNR 2~N times compared with the classical system.If we can efficiently prepare microwave entangled photons,quantum Illumination Radar will play a significant role.Traditional imaging methods have limited resolution and poor anti-interference ability in the optical imaging.The framework of quantum imaging is going to subvert the form of traditional imaging.Imaging is achieved by coincidence measurement of signal and idle two light paths.This imaging uses the fluctuation of the photon and it only needs two bucket detector to complete imaging.Quantum imaging technology is constantly improving and innovating.Quantum imaging is now developing more mature to solve the problem of classical imaging.Starting from the characteristics of quantum system,we focus on quantum detection and quantum imaging.The main contents and innovations of this thesis are as follows.Starting from the preparation of entangled two-photon signals,we use the method of spontaneous parametric down conversion.We built the optical path on the experimental platform.Two single photon detectors are used to detect the photons made,and the converted electrical signals are sent to the coincidence counter to test the results.The similarities and differences between quantum system and radar system are simply analyzed.We mainly studied signal modulation,signal reception and optical signal transmission function.Finally,the main noise sources of quantum system are studied.We analyzed the detection probability of entangled light and classical sources under the condition of noise interference.For the false alarm probability,the entangled light source can be effectively reduced.We use the entangled photons to finish the quantum illumination experiment by parametric down conversion.As a comparison experiment group,the coherent light source is obtained by using the polarization free beam splitter.SNR is calculated by correlation algorithm under different disturbances.The experimental results show that the quantum illumination technology can improve the SNR of the system.We analyze and deduce the signal model of entangled light quantum imaging,then finish the imaging by single point scanning.Due to the large sampling time of point scanning method,we rededuce the model by combining compressed sensing algorithm.Deterministic random sequences are used as observation matrices.We use the compressed sensing algorithm to complete the simulation experiment.Based on the experimental platform,we have completed the experiment of entangled light quantum imaging based on compressed sensing. |
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