Visibility enhancement in two-dimensional lensless ghost imaging with true thermal light**Project supported by the National Natural Science Foundation of China (Grant Nos. 11204117, 11304007, and 60907031), the China Postdoctoral Science Foundation (Grant No. 2013M540146), the Fund from the Education Department of Liaoning Province, China (Grant No. L2012001), and the National Hi-Tech Research and Development Program of China (Grant No. 2013AA122902).

Abstract

We report an experimental demonstration of two-dimensional (2D) lensless ghost imaging with true thermal light. An electrodeless discharge lamp with a higher light intensity than the hollow cathode lamp used before is employed as a light source. The main problem encountered by the 2D lensless ghost imaging with true thermal light is that its coherence time is much shorter than the resolution time of the detection system. To overcome this difficulty we derive a method based on the relationship between the true and measured values of the second-order optical intensity correlation, by which means the visibility of the ghost image can be dramatically enhanced. This method would also be suitable for ghost imaging with natural sunlight.