A theoretical scheme of thermal-light ghost imaging by $N$th-order intensity correlation

In this paper, we propose a theoretical scheme of ghost imaging in terms of $N$th-order correlated thermal light. We obtain the Gaussian thin lens equations in the ghost imaging protocol. We show that it is possible to produce $N-1$ ghost images of an object at different places in a nonlocal fashion by means of a higher-order correlated imaging process with an $N$th-order correlated thermal source and correlation measurement. We investigate the visibility of the ghost images in the scheme, and obtain the upper bounds of the visibility for the $N$th-order correlated thermal-light ghost imaging. It is found that the visibility of the ghost images can be dramatically enhanced when the order of correlation becomes larger.