Influence Of Transversely Inhomogeneous Transmission Of Pseudo-thermal Light Source On Lensless Ghost Imaging

Ghost imaging is a kind of non-local imaging technology based on the spatial correlation of light.In the process of outdoor application,it needs to overcome various noises and interferences from the background environment.The influence of the background environment is mainly reflected by the interference on the transmission path of ghost imaging,and the inhomogeneous transmission of the light source is one of the results caused by the interference in the optical path.This paper mainly studies the influence of transversely inhomogeneous transmission of pseudo-thermal light source on lensless ghost imaging,including the case where the transversely inhomogeneous transmission of light source occurs separately,and the case where the transversely inhomogeneous transmission and the axially inhomogeneous transmission of light source occur together.This paper first studies the influence of transversely inhomogeneous transmission of light source on lensless ghost imaging.Based on classical optical theory,a model of lensless ghost imaging with an inside inclined light source is analyzed.We derive the intensity fluctuation correlation function in lensless ghost imaging when the transversely inhomogeneous transmission of light source is occurred,then we carry out numerical simulation.Finally,we implement experiments to verify our results using inclined ground glass.The results indicate that the transversely inhomogeneous transmission of light source decreases the visibility and signal-to-noise ratio of the reconstructed image.Then this paper studies the influence of the coexistence of transversely inhomogeneous transmission and axially inhomogeneous transmission of light source on lensless ghost imaging.Firstly,the intensity fluctuation correlation function of the lensless ghost imaging system with two inhomogeneous cases coexisting is derived from the ghost imaging theory,and then the simulation is performed according to this function.The effects of different degrees of inhomogeneity and different transverse sizes of the light source on the two inhomogeneous cases are discussed separately when the transverse inhomogeneity and axial inhomogeneity occur simultaneously.The simulation results show that when the transversely inhomogeneous transmission and the axially inhomogeneous transmission of the light source occur together,no effect other than their separate effects will occur,and the effects of the two inhomogeneous cases on the quality of ghost images are independent.The simulation results also indicate that if the transverse size of the light source becomes larger,the influence of the transversely inhomogeneous transmission of the light source is stronger;if the transverse size of the light source becomes smaller,the effect of the axially inhomogeneous transmission of the light source becomes more prominent.The work of this paper is helpful for deepening the understanding of optical path matching and avoiding the influence of inhomogeneous transmission of light source in ghost imaging application.It has some guidance on the selection of the size of light source in ghost imaging under disturbing environments.For example,in applications where it is difficult to correct the inhomogeneity of the light source,it may be considered to change the transverse size of the light source to achieve a compromised imaging result.