Coherent imaging of a pure phase object with classical incoherent light

Bache, M.; Magatti, D.; Gatti, A.; Brambilla, E.; Ferri, F.; Lugiato, L. A.

Coherent imaging of a pure phase object with classical incoherent light

Authors

Description

By using the ghost imaging technique, we experimentally demonstrate the reconstruction of the diffraction pattern of a {\em pure phase} object by using the classical correlation of incoherent thermal light split on a beam splitter. The results once again underline that entanglement is not a necessary feature of ghost imaging. The light we use is spatially highly incoherent with respect to the object ($\approx 2 μ$m speckle size) and is produced by a pseudo-thermal source relying on the principle of near-field scattering. We show that in these conditions no information on the phase object can be retrieved by only measuring the light that passed through it, neither in a direct measurement nor in a Hanbury Brown-Twiss (HBT) scheme. In general, we show a remarkable complementarity between ghost imaging and the HBT scheme when dealing with a phase object.
13 pages, 11 figures. Published in Physical Review A. Replaced version fixes some problems with Figs. 1, 4 and 10