中文摘要：

文章综述了利用光学自发参量下转换过程产生的纠缠双光子态和热光源的空间关联性，实现“鬼”成像、“鬼”干涉、亚波长干涉和非定域双缝干涉等实验的研究进展，以及其中涉及的争论问题。

英文摘要：

We discuss in brief some interesting optical experiments based on intensity correlation measurement, such as ghost imaging, ghost interference, sub-wavelength interference and nonlocal double-slit interference, performed with both entangled two-photon states generated by spontaneous parametric down-conversion, and with thermal light. Some debates in this topic are also mentioned.