The Research Of The Influence From The Incidence Angle On Reflective Ghost Imaging Under Atmospheric Turbulence

Correlated imaging,or ghost imaging(GI),is a imaging technique that has been widely discussed in recent years and has made great progress.The most important characteristic of ghost imaging is nonlocality.The light source is divided into two beams,one beam is illuminated on the object,and then received by a bucket detector without spatial resolution,the other beam is received by the reference detector,and finally the image information or diffraction patterns are reconstructed from the correlation of intensity fluctuations between two detectors.The optical path of ghost imaging does not require an imaging lens,and it has the ability to weaken the effects of atmospheric turbulence on imaging,which makes the ghost imaging have broad application prospects.For example,correlated imaging can be used for remote sensing,spaceborne imaging detection,lidar,infrared imaging,defense military and medical,and traditional imaging techniques will be slowly replaced.In the article,the effects of the incident angle on lensless ghost imaging and ghost diffraction system are studied under atmospheric turbulence conditions.At the same time,the reflective ghost imaging(RGI)and direct imaging(DI)under atmospheric turbulence are compared and analyzed.Finally,the influence of atmospheric turbulence intensity on the reflective ghost diffraction is also studied.The research content and innovation of the paper are as follows:Firstly,we study the influence of incident angle on the RGI system through atmospheric turbulence.By utilizing the extended Huygens-Fresnel integral formula,the expression of the point spread function of the reflective ghost imaging is derived.Through the variation of the point spread function,the influence theof incident angle on the RGI under atmospheric turbulence is analyzed.It is shown that under moderate turbulence,when the incident angle is relatively small,the quality imaging of GI is better than DI.An increase of the incident angle will make the obvious degradation of the imaging quality in direct imaging,while the change of the ghost image is quite small during this process.After verification by numerical simulation,we find that the results of our analysis are consistent with the numerical simulation.Secondly,to discuss the influence theof large incident angle on the ofquality imaging the RGI under atmospheric turbulence,we further increase the incident angle and find that the imaging quality of direct imaging and ghost imaging get worse with the incident angle increasing,but ghost imaging can obtain a relativelygood ghost-image,so RGI is more robust against the change theof incident angle than DI under the same conditions.The numerical simulation also validated the analysis.We also introduced the fidelity to judge the ofquality imaging the system.The higher the fidelity,quality.imaging better the theFinally,the influence of incident angle on the lensless ghost diffraction system under atmospheric turbulence and the influence of atmospheric turbulence intensity on the reflective ghost diffraction are studied.The results of our analysis and the results of numerical simulations show that both the incident angle and the intensity of atmospheric turbulence affect the imaging quality.When the intensity of atmospheric turbulence is constant,increasing the incident angle will make the imaging quality better.When the incident angle is constant,increasing the intensity of atmospheric turbulence will make the imaging quality worse.