The First Ghost Image ( II )

 Right now we are working on spatial correlation and very soon we will be able to observe the ghost image of an object mask with sunlight as a source. This result can be interpreted as a nonlocal point-to-point image-forming correlation which is the result of interference between two-photon amplitudes, corresponding to different yet indistinguishable alternative ways of triggering a joint photodetection event. As a result of two-photon interference, ghost imaging has two peculiar features:(1) it is nonlocal and (2) its spatial resolution which is better from that of classical imaging. Consequently, ghost imaging using the sun as a light source could achieve spatial resolution equivalent to that of a classical imaging system taking pictures at a distance of 10km with a 92m-diameter lens. In conclusion, this experimental demonstration of sunlight-based ghost imaging raises a fundamentally im-portant question about whether the nonlocal ghost-imaging effect of classical thermal light is caused by quantum-mechanical two-photon interference.



References
1. T.B. Pittman, Y.H. Shih, D.V. Strekalov, and A.V. Sergienko, Phys. Rev. A52, R3429 (1995).
2. A. Valencia, G. Scarcelli, M. D'Angelo, Y. H. Shih, , Phys. Rev. Lett.94, 063601 (2005); G. Scarcelli, V. Berardi, Y. H.
Shih, Phys. Rev. Lett.96, 063602(2006); R. Meyers, K. S. Deacon, Y. H. Shih, Phys. Rev. A77, 041801(2008); Y. Shih,
SPIE News, Electronic Imaging and Signal Processing, July, (2009).
3. A. Gatti, E. Brambilla, M. Bache, L. A. Lugiato, Phys. Rev. Lett.93, 093602(2004); Phys. Rev. A70, 013802(2004).
4. D. Zhang, Y. Zhai, L. Wu, X. Chen, Optics Letters30, 2354(2005).