Quantum Detection Method And Experimental Research Of Entangled Photon Under Noisy Conditions

Since the end of the nineteenth century,with the continuous development and improvement of quantum theory,the combination of quantum theory with other disciplines also has rich applications.More representative fields include quantum detection,quantum imaging,quantum computing,quantum secure communication,etc.In the field of quantum detection,entangled quantum signals have excellent characteristics such as super-resolution,antiinterference,and low interception,which greatly improve the sensitivity of target detection and imaging resolution compared with classical signals.Especially in the case of weak signals and strong background noise,the advantages of detection and imaging technology based on entangled quantum signals are more obvious.Therefore,it has huge development potential and application prospects in the civil and military fields.In recent years,it has caused more and more attention.Although quantum imaging based on entangled states can theoretically break through the Rayleigh diffraction limit and achieve super-resolution imaging,and thanks to its signal characteristics and system structure,quantum imaging has anti-interference capabilities that classical signals do not have,making it can be imaged with high quality under sub-shot noise conditions.However,due to the influence of noise inside the optical system,the quantum imaging performance will be greatly affected.Whether it can overcome the errors caused by the system noise in the quantum detection system determines whether the system can give full play to the advantages of entangled state quantum signals,and is also an important guarantee for the further development of entangled state quantum detection imaging and its practical application.In order to solve the above problems,based on the characteristics of the system noise of the entangled state quantum imaging system,this paper focuses on the relevant theories and experiments of the target reconstruction algorithm of the entangled state quantum imaging system against the system noise.The main research content includes the following aspects:(1)The spontaneous parameter down-conversion method of type ? BBO crystal was used to complete the preparation of the entangled two-photon signal,and the prepared entangled signal was measured by coincidence,which verified the strong correlation of the entangled signal.Combining the imaging principle and the system structure designed,the optical transfer function in the system and the working principle of the main components and equipment are further analyzed,which lays the foundation for the research of highperformance system detection.(2)The target detection performance of classical signal and quantum entangled signal is analyzed,and the target detection comparison experiment of quantum entangled signal and classical signal is designed,which verifies the sensitivity advantage of quantum signal over classical signal target detection.The characteristics of noise and signal are further analyzed,and the theory of quantum target detection under Gaussian noise conditions is established.Based on this theory,simulation and experiment verify the good target detection ability of entangled signal.(3)Improved the scanning quantum imaging experimental plan proposed by Pittman.By using the spatial light modulator instead of the scanning quantum imaging of the fiber head in the reference path,the complexity of the system is reduced,the requirements on the equipment are also reduced,and the scanning speed is increased.And make the scanning route programmable,which enhances the flexibility of the system.In addition,further considering the influence of Poisson noise caused by the experiment system,the spatial light modulator scanning quantum imaging experiment under the Poisson noise condition was completed,and better experimental results were obtained.(4)Combining compressed sensing technology with entangled state quantum imaging,considering the mathematical model of compressed sensing quantum imaging with Poisson noise,proposes anti-Poisson noise compressed sensing quantum imaging model and its algorithm,and verifies the effectiveness of the proposed method through simulations and experiments.It can effectively eliminate the equipment noise in the system.