Spatially offset optical coherence tomography : leveraging multiple scattering for high-contrast imaging at depth in turbid media
Abstract
The penetration depth of optical coherence tomography (OCT) reaches well beyond conventional microscopy; however, signal reduction with depth leads to rapid degradation of the signal below the noise level. The pursuit of imaging at depth has been largely approached by extinguishing multiple scattering. However, in OCT, multiple scattering substantially contributes to image formation at depth. Here, we investigate the role of multiple scattering in OCT image contrast and postulate that, in OCT, multiple scattering can enhance image contrast at depth. We introduce an original geometry that completely decouples the incident and collection fields by introducing a spatial offset between them, leading to preferential collection of multiply scattered light. A wave optics–based theoretical framework supports our experimentally demonstrated improvement in contrast. The effective signal attenuation can be reduced by more than 24 decibels. Notably, a ninefold enhancement in image contrast at depth is observed in scattering biological samples. This geometry enables a powerful capacity to dynamically tune for contrast at depth.
Citation
Untracht , G , Chen , M , Wijesinghe , P , Mas , J , Yura , H , Marti , D , Andersen , P & Dholakia , K 2023 , ' Spatially offset optical coherence tomography : leveraging multiple scattering for high-contrast imaging at depth in turbid media ' , Science Advances , vol. 9 , no. 27 . https://doi.org/10.1126/sciadv.adh5435
Publication
Science Advances
Status
Peer reviewed
ISSN
2375-2548Type
Journal article
Description
Funding: Horizon 2020 FETOPEN, GRANT #(s) 863203; European Union FAMOS, GRANT #(s) 317744; UK Engineering and Physical Engineering and Physical Sciences Research Council (EPSRC) EP/M000869/1 and EP/P030017/1; Australian Research Council, FUNDREF 10.13039/501100000923, GRANT #(s) FL210100099; Horizon 2020 Framework Programme, FUNDREF 10.13039/100010661, GRANT #(s) 871212.Collections
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