A Scheme For Anti-Scattering Imaging Beyond A Single Memory Effect Range

Traditional optical imaging is one of the most important ways for information acquisition.It relies on a ‘point-to-point' mapping achieved by propagations of light in free space between the object plane and the imaging plane.However,in practical applications,this ‘point-to-point' mapping could be destroyed to some extent,for the existences of various diffusers,resulting in a decline on imaging qualities or even failures in imaging.Anti-scattering imaging techniques based on memory effect(ME)gain great attentions for its relatively simple optical setups without any prior information.However,a limited field of view(FOV)is the biggest difficulties such techniques should surmount.On the other hand,correlated imaging gain great attention for its special non-local spatial correlation.Recent researches show its capabilities to realize an anti-scattering imaging.We find that both anti-scattering imaging based on ME and correlated imaging construct their ‘point-to-point' mapping based on the second order coherent function of speckle patterns,which appears to be a single-peaked function.And notice that the FOV of correlated imaging is only limited to the range of illumination,so we consider the possibility by utilizing some properties of correlated imaging to achieve an extended FOV in antiscattering imaging based on ME.In this thesis,a comparison is made between these two imaging techniques about the means of data extractions,the requirements for spatial coherence and temporal coherence.For means of data extractions,both are based on the second order coherence of light field.However,the former requires a spatial ensemble average while the latter a temporal ensemble average.For spatial coherence,their imaging resolution are both limited by the spatial coherence of light field.However,the former one's limitation comes from the diameter of the diffusers while the latter comes from the diameter of the light sources.As for temporal coherence,both require a maintain temporal coherence of the light field during imaging process.However,the former takes a high contrast ratio of speckle patterns sampled into consideration while the latter takes the characteristic time of fluctuation of the light field and the matching between two arms.Based on this comparison,a scheme for anti-scattering imaging based on memory effect by utilizing cross-correlation is proposed,under which an imaging of moving object beyond a single memory effect range can be achieved.And some simulations and experiments are carried out to make verifications for feasibilities of this scheme.The scheme for anti-scattering imaging based on memory effect by utilizing crosscorrelation has an extended FOV for imaging,can realize fast and direct extractions of data without iterative algorithm,and able to tracing moving objects.