Theoretical And Experimental Investigation On Pseudothermal And Quantum Correlated Imaging

Correlated imaging, also called ghost imaging or coincidence imaging, is a novelimaging scheme developed at the end of last century. The peculiar nonlocal featuremakes it very different from classical imaging methods. It exploits two spatiallycorrelated light beams: a signal beam, which interacts with the target and then ismeasured by a single-pixel bucket detector, and a reference beam, which is directlymeasured by a high spatial-resolution detector. An intensity cross correlation betweenthe signal beam and the reference beam imparts the correlated image to the crosscorrelation between the photocurrents obtained from the two detectors. But thetarget’s image is unavailable from either photocurrent alone.According to the types of light sources, correlated imaging can be divided intoquantum correlated imaging and thermal light correlated imaging. Since firstdemonstrated experimentally by Pittman et al. in1995, more and more researchers areinvolved into the theoretical and experimental investigations of correlated imaging.Although the essential of this phenomenon is still under debate for its quantum orclassical origin, correlated imaging and its relevance to application have been carvingtheir way for advancing.In this thesis, to pave the way for real applications of correlated imaging,pseudothermal lensless two-color correlated imaging and standoff two-color quantumcorrelated imaging through turbulence are studied theoretically first, and thencorrelated imaging experiments from transmissive to reflective cases are exploredwith pseudothermal light generated by passing a laser beam through a rotating groundglass.The structure and main contents of this thesis are as follows:1. The basic concepts of correlated imaging are introduced firstly. Then the historyand development status of correlated imaging are briefly reviewed. Finally basictheoretical analyses are introduced about the pseudothermal and quantum correlated imaging.2. Two-color (or nondegenerate-wavelength) lensless correlated imaging with apseudothermal light source is investigated theoretically based on theGaussian-Schell model and classical optical coherence theory. The determiningfactor for the visibility and resolution of two-color pseudothermal lenslesscorrelated imaging is obtained and the theoretical results are also confirmed bynumerical simulations.3. We analyze theoretically the performance of a standoff quantum two-colorcorrelated imaging configuration through turbulence. Based on the extendedHuygens-Fresnel integral, modeling the beams as in zero-mean jointly Gaussianstates, and using a quadratic approximation of the turbulence structure function, aformula is derived to depict the ghost image formed through turbulence of astandoff reflective object. Numerical calculations are also performed based on theformula to show how to improve the image quality and mitigate the influence ofthe turbulence.4. Transmissive and reflective correlated imaging are studied experimentally with apseudothermal light source. Utilizing pseudothermal light generated by passinga He-Ne laser through a rotating ground glass plate and synchronously triggeringthe data acquisition system, a correlated image of transmissive stencil lettersXIOPM is recovered. Especially, how the system parameters setting in theexperiment affect the image quality is investigated in the transmissionconfiguration. To pave the way for practical stand-off sensing applications,reflective correlated imaging of a letter V is also investigated.5. We summarize the main contents and put forward prospect of our furtherresearch.