Coherence gate manipulation for enhanced imaging through scattering media by non-ballistic light in partially coherent interferometric systems.

Abstract

Coherence gating is typically exploited for imaging through disordered media by least-scattered (ballistic) light. Ballistic light-based approaches produce clear images only when the proportion of ballistic to multiply scattered (non-ballistic) light is relatively high. To overcome this limitation, we counterintuitively utilize the coherence gate to image by the non-ballistic light, enabling us to retrieve information missing in the ballistic image. We show that non-ballistic images acquired by transversal coherence gate shifting have image quality and spatial resolution comparable to the ballistic image. Combining images for different coherence gate positions, we synthesize an image of quality superior to ballistic light approaches. We experimentally demonstrate our concept on quantitative phase imaging through biological tissue.