Ghost Imaging Based On Prefabricated Light

Ghost imaging is a new imaging method based on multiple measurements and second-order correlation of the light field.Compared with the traditional first-order imaging,ghost imaging has become the current research hotspot for its untouched imaging,super-resolution and lensless imaging.After nearly thirty years of theoretical and applied research,the light source for realizing ghost imaging has been extended from entangled light sources to pseudo-thermal light sources and even classical heat light sources.However,ghost imaging requires a large number of measurements,complex and sophisticated optical paths,and unsatisfactory imaging quality are still its shortcomings that cannot be ignored.For this reason,computational ghost imaging was proposed,which overcomes the shortcomings of traditional ghost imaging by using modern optical modulation devices and computer technology.However,computational ghost imaging also introduces new problems into the study of ghost images.Such as how to design the illuminate light,how to make sure the accuracy of optical modulation and optical diffraction calculations?These problems have become an important reason for constraining the development of computational ghost images.To solve these problems,this article through prefabricated light field ghost imaging research,made the following major innovations are as follows:1.Based on the understanding of the traditional ghost imaging of pseudo-thermal light source and problems of traditional computational ghost imaging,an experimental idea is proposed to introduce computational holography into computational ghost imaging.To a certain extent,this method solves the problems such as the speckle distribution can not be dynamically adjusted,the speckle particle size is uneven,and the speckle blurring.What is more,using computational holography can avoid the difficult of the inaccuracy of optical diffraction calculation in the traditional computational ghost imaging.The experimental result shows that the imaging performance of the computational ghost imaging based on holographic reconstruction is better than that of the traditional ghost imaging with pseudo-thermal light.2.The effect of the ratio of the area of the target to the area of the light field on the imaging quality of ghost images was studied by means of computer simulation.Simulation results show that as the area of the object increases,the number of samples required for ghost imaging will also increase.In addition,we also investigate the effect of speckle sparsity(the ratio of the number of speckles in the speckle field to the total number of speckles)on the imaging quality of the ghost images and find that in the case of sufficient number of samples,Can achieve better imaging quality.3.The ghost imaging based on sparse speckle position modulation is explored.By changing the position of the sparse speckle under the Gaussian distribution,exponential distribution,Rayleigh distribution,Beta distribution,Poisson distribution and lognormal distribution respectively,we found the ghost imaging shows different features under different distributions.The feature of partial imaging of the imaging result based on the speckle position modulation of sparse speckle is impressed.At last,Gaussian distributed sparse speckle computing ghost imaging is selected to verified by experiment,and compared with the traditional random speckle computing ghost imaging.Experimental results show that imaging performance of Gaussian distributed sparse speckle computational ghost imaging is better than traditional random speckle computational ghost imaging.In addition,the experimental results show that the normalization operation will greatly reduce the imaging performance of Gaussian distributed sparse speckle imaging ghost imaging.