Sensing and Imaging of Moving Objects in Heavily Scattering Media Using Speckle Intensity Correlations

Imaging and sensing through opaque scattering media is a topic of broad interest with a wide range of applications. Methods are impacted by speckle, which refers to grainy patterns of bright and dark spots resulting from coherent interference as light propagates through a randomly scattering medium. This phenomenon is most often considered undesirable in applications. However, it is possible to leverage the information contained in speckle patterns to image hidden objects. In practice, most methods are limited to situations in which the scattering medium is either thin or weakly scattering. This thesis explores a motion-based coherent imaging and sensing method originally developed by prior researchers. This technique takes advantage of heavy scatter and object motion, with no theoretical limit on the amount of scatter. In this method, intensity correlations are performed on speckle images taken with the object at different spatial locations. Prior research led to the development of a theory that describes the relationship between speckle intensity correlations and the object's geometry. This thesis presents substantial new understanding pertaining to the theory that allows for the imaging of general objects in heavily scattering media. Additionally, it is shown that two nominally identical objects can be distinguished through speckle intensity correlations over far-subwavelength translation distances, implying access to the microstructure of objects. Finally, the combining of this method with diffusion-based localization is demonstrated, providing a way to apply this imaging and sensing method without prior knowledge of the object's relative spatial locations.