Imaging through Turbidity

Field-based assessment of scattering matrix
In optical bioimaging, one of the key challenges has been the limited imaging depth. When light propagates through thick biological tissues, the propagating wave is distorted with the increase of the target depth. The delivery of the excitation wave is severely disturbed, which results in the loss of the spatial resolution and reduction in the light delivery. As a result, thick biological tissues appear to be opaque and turbid. In order to account for these deteriorating effects of the turbid tissues, we will use our quantitative phase microscopy (QPM) techniques to characterize their optical properties. The QPM is especially suitable for this purpose since it can record both the amplitude and phase of the light wave. This is critical in that the turbidity of the biological tissues affect not only to the amplitude but also to the phase of the propagating wave. In our approach, we will record the scattering matrix of a given tissue and thereby make a deterministic connection between the input and output waves. This approach will enable us to see through thick biological tissues in transmission and lay the foundation to the deep tissue imaging in reflection.