Research On Microscopic Imaging Method Based On SLM Simulated Scattering Media Speckle

Strong scattering media are ubiquitous in nature.Penetrating scattering media imaging is a key issue in many optical imaging fields such as atmospheric remote sensing,biomedical detection,and underwater target detection.In order to realize clear imaging of targets in the scattering medium,a non-invasive,high-resolution scattering microscopic imaging method based on the optical memory effect combined with the principle of ptychography is studied.In this paper,current scattering microscopic techniques is analysis,and the simplified model experiments is implemented by using spatial light modulation(SLM).The research content of this paper is mainly carried out from three aspects: the theoretical model of scattering imaging,system design and simulation,and principle verification experiments.First,the strong scattering characteristics of the random scattering medium are analyzed,and the random speckle field formed by the target's front scattering medium is used as a special illumination beam.Combined with the optical memory effect theory,the target's back scattering medium is considered as a part of the linear invariant microscopic imaging system.Construct the theoretical model of scattering imaging.In order to reconstruct the target image,control the illumination angle of the beam to make the target plane random speckle move in the specified way,realize the modulation of the ideal target frequency domain information,and obtain a series of correlated low-resolution target images in time sequence.With the help of Fourier ptychographic imaging,the optimal solution of the target that satisfies the constraints of the system is solved,and the iterative fusion of the target spectrum is finally completed in the frequency domain.In this method,the target imaging will not be disturbed by the scattering medium,and it will make full use of the light scattering characteristics of the medium to achieve high-resolution imaging of the target.Secondly,in order to complete the preliminary principle verification of the scattering microscopy imaging method based on the optical memory effect and the ptychographic imaging principle,an overall simplified model of the scattering microscopy imaging system was designed,and the unit module parameters were optimized,including the micro projection module,Micro imaging module,light scattering simulation module.The overall numerical simulation of the scattering microscopy imaging system under multiple parameters was performed,and the feasibility of the theoretical model was verified.Finally,according to the simplified model of the scattering microscopy imaging system,the light scattering simulation of the scattering medium is realized by using the spatial light modulator and the micro-projection system,and the construction of the overall optical path and the system verification are completed.Using the self-built scattering microscope imaging system to image the USAF-1951 resolution plate,the contrast and resolution of the reconstructed target have been significantly improved.The reconstructed target image can clearly observe the fifth pair of engraved lines in the eighth group,and the original target image can only observe the first pair of engraved lines in the eighth group,which is nearly 2 times higher than the original target image resolution.The feasibility of this method was verified by experiments.