Study On The Influence Of Detector Response Characteristics On Ghost Imaging

Ghost Imaging(GI),or correlation imaging,which uses the intensity fluctuations of light fields to restore information about objects,has received widespread attention in recent years.Due to the advantages of simple system structure,strong anti-interference,the ability to achieve super resolution imaging and breakthrough diffraction limit imaging,correlation imaging has a very broad application prospect.In ghost imaging systems,bucket detectors,as core devices,are important factors that affect the quality of reconstructed images in ghost imaging.As a key characteristic parameter of the detector,the response characteristic is the focus of this thesis.Therefore,based on ghost imaging systems,this thesis explores the impact of detector response characteristics on the imaging quality of ghost imaging.Firstly,the influence of detectors in different response regions on the reconstructed image quality of ghost imaging in the absence of noise is discussed.It is found that when using Hadamard speckle as illumination speckle,the spatial information of the object can be recovered in any response region,and the response characteristics of the detector have little impact on the reconstructed image of ghost imaging.Using random speckle as illumination speckle can restore spatial information of objects in most response regions.In the case of using wavelet illumination patterns and discrete cosine speckle as illumination speckle,when the detector is in the nonlinear response region,the spatial information of the object cannot be restored in most cases.Secondly,we discuss the impact of noise on the reconstructed image quality of ghost imaging when the detector is located in different response regions.It is found that Hadamard speckle and random speckle have strong anti-interference ability,and most of them can still better recover the spatial information of objects when used as illumination speckle.Finally,a direct imaging system is introduced and discussed.When the detectors are in different response regions and there is noise,the imaging quality of the direct imaging system and the ghost imaging system is compared.It is found that the ghost imaging system is superior to the direct imaging system.