Coherent incident field information through thick random scattering media from speckle correlations over source position.

With two nonoverlapping beams incident at different angles on a heavily scattering medium, the spatial correlation of speckle patterns over source position has a beat that is related to the incident angle difference. A model presented explains the measurement. The spatial correlation is shown to decorrelate faster than the beam intensity correlation function and to be sensitive to the incident field profile. Increased scatter results in more rapid decorrelation. This work suggests new opportunities for imaging through scattering media.