Imaging Through Random Scatterer with Spatial Coherence Structure Measurement

Optical coherence is becoming an efficient degree of freedom for light field manipulations and applications. In this work, we show that the image information hidden a distance behind a random scattering medium is encoded in the complex spatial coherence structure of a partially coherent light beam that generates after the random scatterer. We validate in experiment that the image information can be well recovered with the spatial coherence measurement and the aid of the iterative phase retrieval algorithm in the Fresnel domain. We find not only the spatial shape but also the position including the lateral shift and longitudinal distances of the image hidden behind the random scatterer can be reconstructed, which indicates the potential uses in three-dimensional optical imaging through random scattering media.

Spatial Coherence Manipulation on the Statistical Photonic Platform

Coherence, like amplitude, polarization and phase, is a fundamental characteristic of the light fields and is dominated by the statistical optical property. Generally, accurate coherence manipulation is challenging since coherence as a statistical quantity requires the combination of various bulky optical components and fast tuning of optical media. Spatial coherence as another pivotal optical dimension still has not been significantly manipulated on the photonic platform. Here, we theoretically and experimentally realize accurate manipulation of the spatial coherence of light fields by loading a temporal random phase distribution onto the wave-front on the statistical photonic platform. By quantitatively manipulating the statistical photonic properties, we can successfully achieve the partially coherent light with the pre-defined degree of coherence and continuously modulate it from fully coherent to incoherent. This design strategy can also be easily extended to manipulate the spatial coherence of other special beams such as partially coherent vortex beam generations. Our approach provides straightforward rules to manipulate the coherence of the light fields and paves the way for applications of partially coherent beams in information encryption, ghost imaging, and information transmission in turbulent media.