Study On Correlated Imaging Schemes With Complex-valued Object And Nonuniform Source

The correlated imaging is a new imaging technique which can obtain the retrived image of theobject and control its’ quality by using the fluctuation of the classical or quantum light field and themeasurement of the high-order statistics of light field (eg. correlation function). It can obtain theretrived images with high-quality beyond the standard imaging techniques. Therefore, it has a broadapplication prospect. This thesis will study the correlated imaging schemes for the complex-valuedobject and for the nonuniform light field.It is shown that one can only get the amplitude information, but not the phase information oftarget object by correlated imaging system since the coincidence counting is taken on thesecond-order intensity correlation in correlated imaging systems. But phases information alwayscarry some special information of the target objects. In this thesis, a new correlated imaging schemeto retrive the amplitude and phase information of a complex-valued object has been proposed. In thescheme, the beam splitters and a π/2phase-changing plate were used to separate the real andimaginary part of the object, and the real and imaginary part information were then individuallyreconstructed by correlated imaging technique. The results show that the scheme can apply to ageneral complex-valued object, especially, the acquisition of its’ phase information.Furthermore, compressive sensing reconstruction algorithm was introduced to the proposedscheme, and the compressive complex-valued ghost imaging scheme based on phase modulation isproposed. This scheme can dramatically decrease the measurement times and improve the quality ofthe reconstruted images, especially the phase of the complex-valued object. The numericalsimulation results show that only about40%of the Nyquist limited measurement times was used toreconstruct the imaging, where the mean square error (MSE) of the reconstruted image was about10-2, so the efficiency of imaging was improved obviously.Lastly, the light field interacted with object was always nonuniform in correlated imagingimplementation. That led a lose of the marginal information of the retrieved image. On the basis ofuniformly weighted ghost imaging scheme, a uniformly weighted nomorlized ghost imagingscheme was proposed to overcome the marginal information losing problem. Furthemore, thecompressive sensing method was used in the uniformly weighted ghost imaging scheme to improvethe quality and efficiency of imaging. MSE was selected as the objective parameter to compare theperformance of the proposed scheme under three different nonuniform levels of light field. The results show the scheme can overcome the influence of the nonuniform field effciently, and willcontribute to the practical usage of correlated imaging.