Nonlocal Spatial Filtering Process With Thermal Light

Based on the HBT experiment scheme,the coherent time of the source is measured by the second order correlation property of the thermal light.And the influencing factors of the coherent time of the light source are investigated.In this paper,we design and complete the lensless ghost imaging experiment with thermal light.At the same time,we expatiate the role of different refractive index medium in compensating optical path difference.Furthermore,the thermal light lens "ghost" imaging scheme was completed,and the experimental results were consistent with the theoretical calculation.For the first time,we proposed and designed the nonlocal spatial filtering with thermal light,and completed the spatial filtering process with the thermal light.The research results show that the spatial filtering process can still be realized with the incoherent thermal light source.And the processing results are consistent with the classic Abbe-Potter filtering process;At the same time,this experimental scheme can release the requirement of the coherence the light source.The experimental scheme also has the non-localized characteristics,which has potential applications in remote sensing,geological surveying and information optics.In the first two chapters the research background and research status of the "ghost" imaging are introduced,respectively.Chapter 3 to 5 introduce the three main tasks completed during the master's period,namely:In this paper,the influence factors of the correlation time of thermal light are studied.And the two variables,the transverse dimension of the light source and the rotation speed of the wool glass,are selected.The study shows that the transverse size of the light source has no significant influence on the coherence time.However,the faster the wool glass speed,the shorter the coherence time.Further,we discuss the visibility of the image when the time delay exists in the correlation measurement process.In the meanwhile,the thermal light ghost imaging of different coherence time is performed.The experimental results suggest that when the coherence time decreases,the resolution of the image will decrease.We design and complete the lensless ghost imaging experiment with thermal light,and discuss the theoretical feasibility of using different refractive index to compensate the optical path difference.Here,two kinds of thermal light lens “ghost” imaging experimental scenario are carried out.One of the scenarios is that the detected object and the imaging lens are placed nonlocally in two different optical paths.In the other scenario,the detected object and the imaging lens are both placed in the signal beam.The imaging process and imaging magnification were theoretically calculated.We first propose the experimental scheme of nonlocal spatial filtering with thermal light.And we realize the process of the non-local spatial filtering with thermal light.The experimental scheme differs from the Abbe-Porter spatial filtering scheme in that:(1)the light source is different.The Abbe-Porter spatial filtering uses the coherent laser light source,while in our experiment the incoherence thermal light source is used.(2)The measurement is different.The Abbe-Porter experimental results were obtained by using the intensity distribution measurement.The experiment in this paper was based on the second-order correlation property of thermal light,and the experimental results were obtained by coincidence measurement.(3)The positional relation between the object and the filter.In the Abbe-Porter filtering experiment,the objects and filters are placed in the same optical path.While in our experimental scheme,the objects and filters are placed in two optical paths,which have nonlocal characteristics.The research results show that the modulated images of the spatial filtering with thermal light have the same fluctuation patterns with the modulated images in the Abbe-Potter filtering experiment.