Dynamic Light Scattering

Optical Coherence Tomography (OCT) serves as a valuable modality for imaging retinal structures, yet encounters challenges related to resolution and depth penetration. Full-field OCT holds promise but is impeded by speckle noise, an interference-related issue. Spatio-temporal coherence tomography (STOC) addresses speckle noise through phase modulation, but spatial resolution improvement remains a formidable task.

In our pursuit of enhanced spatial resolution, we investigate the application of dynamic light scattering (DLS) as a novel approach to modulate the sample arm. By illuminating the dynamic sample with laser light, we intentionally reduce spatial coherence, thereby decorrelating scattered light and diminishing interference patterns responsible for speckle noise. Both DLS and STOC share a common objective in mitigating the effects of light scattering and elevating overall image quality.

The figure presents a qualitative analysis of spatial resolution improvement along the fast (horizontal) and slow (vertical) scanning axes. The intensity images of the horizontal and vertical bars were generated by averaging intensities within the specified regions of interest, indicated by blue rectangles (OCT only) and orange rectangles (OCT + DLS). By employing dynamic light scatterers, we achieve not only enhanced resolution but also improved image contrast.