Study On The Theory And Application Of Correlated Imaging

As a newly imaging technique,correlated imaging attracts more and more attention in recent years.Correlated imaging is an imaging technique which utilizes high-order correlation of light field,and it can be realized with entangled light source and spatially independent light source.Because of the particular imaging technique and the peculiarity of nonlocality,high-resolution and overcoming the atmospheric disturbance,the basic theory of correlated imaging has drawn much attention of researchers.Meanwhile,as its huge potential application in practice,its application in practice has also attracted much attention.In this dissertation,we mainly work on high-order correlation of light field and its application in correlated imaging.The main content includes:The aspect of theory:Firstly,second-order spatial correlation of entangled light source and spatially independent light source in different mean photon number level is studied,and its physical picture is investigated.Then,the influence of detection mode and photon statistic on second-order spatial correlation is obtained,and the difference of second-order spatial correlation with entangled light source and spatially independent light source is found.Secondly,the schemes to generate different types of high-order correlation with programmable light sources are proposed,and the influence of different kinds of phase modulation on high-order correlation is studied.It is found that the properties of high-order correlation with different entangled state can be realized with different types of phase modulation,including high-order GHZ-type and W-type correlation.The aspect of application:Firstly,lensless Fourier-transform correlated imaging is investigated quantitatively.It is found that lensless Fourier-transform correlated imaging can be regarded as a coherent imaging system,and the imaging condition is obtained.Furthermore,the factors influencing the imaging quality,the resolution and contrast,are studied.Secondly,correlated imaging with the programmable light source is investigated.First of all,the sub-Rayleigh imaging scheme can be realized by modulating the amplitude and phase of coherent light,and the imaging resolution of the optical imaging system can be improved.Then,by use of the Gerchberg-Saxton(GS)iterative algorithm,the non-negative exponential speckle patterns can be generated by modulating the phase of the coherent light,which can be used to realize correlated imaging.Furthermore,the influence of the obtained non-negative exponential speckle patterns on the imaging quality of correlated imaging is analyzed.Meanwhile,to investigate correlated imaging with the programmable light source experimently,we realize the correlated imaging system with the programmable light source experimently,which can promote the applicaton of correlated imaging in practice.Thirdly,two schemes of subwavelength interference are realized by modulating the amplitude and phase of coherent light,and they can improve the resolution of the optical system.In scheme 1,the subwavelength interference scheme can be realized with a single-pixel detector.Furthermore,the obtained interference pattern can be inverted to obtain high-resolution image of the object.Meanwhile,in scheme 2,the higher resolution interference pattern can be obtained by modulation the phase of coherent light source combing with high-order correlation algorithm.Lastly,image encryption scheme with entanglement is presented.In this scheme,the image encryption procedure is separated into two modes: authentication and message mode.Any attacking will be discovered by checking the correlation between the measurement results of the legal participants in authentication mode.Only after checking that there is no attacking,the measurement results of Alice in message mode will be sent to Bob,then the image of the object can be obtained by calculating the correlation function.In this scheme,Alice and Bob do not need to share a secret key in advance.Meanwhile,entanglement is employed as for guaranteeing the security of quantum channel,as well as for transmitting the image of the object.