Partially Coherent Light Passes Through The Correlation Imaging Of Non-Kolmogorov Turbulence

Correlated imaging,also called "ghost imaging" or two-photon imaging,is a novel imaging scheme developed at the eighties of last century.With the different from traditional optical imaging,it is a kind of nonlocal imaging method,obtaining the image of unknown object by means of high-order correlation of light field(intensity fluctuation correlation).Light source emits two beams with spatial correlation:a beam through test channel illuminates the unknown object and transmission or reflection signal is received by a bucket detector without spatial resolution capacity;another beam through reference channel is measured by a array detector.Finally,the output signals of the two detectors are sent to a computer to measure the second-order intensity correlation which directly obtained the "ghost”image of unknown object.In this paper,we focus on the extensive application of correlated imaging in long-distance imaging and sensing technology,then investigate in detail that the influence of non-Kolmogorov turbulence on correlated imaging with partially coherent light in the visibility and resolution.The previous Kolmogorov power spectrum deviate from statistical characteristics of atmospheric turbulence,after that,we introduce non-Kolmogorov turbulence which accurately describes statistical characteristics of atmospheric turbulence.Based on non-Kolmogorov turbulence model,it is important practical significance to investigate effect of non-Kolmogorov turbulence on correlated imaging.it provides a theoretical basis for the real application of correlated imaging(such as:correlated imaging radar).The main contents of this paper are listed as following five parts:1.Firstly,we briefly introduce the basic concept of the correlated imaging,then,illustrate in detail the development history of correlated imaging,separately introduce quantum correlated imaging and classical correlated imaging.Finally,we analysis their similarities and differences by comparing with traditional optical imaging and correlated imaging.2.In part two,we mainly introduce the formation mechanism of atmospheric turbulence,and illustrate in detail the physical meaning of various turbulence parameters.In addition,we find that the intensity of atmospheric turbulence only depends on inner scale、outer scale、structure constant and generalized exponent.After that,we respectively introduce two kinds of frequently-used power spectrum:Kolmogorov turbulence power spectrum and non-Kolmogorov turbulence power spectrum.3.Then,we study the influence of non-Kolmogorov turbulence on correlated imaging with partially coherent light.Based on the extended Huygens-Fresnel integral and the propagation properties of partially coherent Gaussian-Schell beams through non-Kolmogorov turbulence,the second-order intensity fluctuation correlation function of correlated imaging with partially coherent Gaussian-Schell beams through non-Kolmogorov turbulence has been derived.Then numerical stimulation based on above theoretical result,investigating the factors that affect resolution and visibility of correlation imaging.Numerical result indicates:The resolution and visibility of correlated imaging are not only affected by the propagation distance,but also the non-Kolmogorov turbulence intensity(structure constant、generalized exponent、inner scale and outer scale)and the coherence length of the light source.Moreover,in the speckle-to-speckle correlated imaging,the source transverse size only determines the visibility of the correlation imaging,without affecting the resolution.4.Finally,we mainly investigate the effect of non-Kolmogorov turbulence on the resolution of lensless computational ghost imaging.Based on the extended Huygens-Fresnel integral and spatial light field coherence theory,the second-order intensity fluctuation correlation function of lensless computation ghost imaging with partially coherent beams through non-Kolmogorov turbulence has been derived,and numerically simulate based on above theoretical result.We find that the resolution of lensless ghost imaging is determined by three factors:propagation distance,turbulence intensity and light source parameters,and atmospheric turbulence between the object and collection lens has little influence on lensless computational ghost imaging.Moreover,comparing with speckle-speckle correlated imaging,in the lensless computational ghost imaging,the greater source transverse size corresponds to stronger resolution.5.We summary the main achievement,and prospect the application for correlated imaging in the feature.