Optical coherence tomography relies on the coherence of light that is backscattered from the sample with interference playing the important role of gating to allow an accurate determination of the origin of any retrieved signal. OCT images of highly-scattering samples suffer from multiple-scattering of light, which leads to speckle as an important noise contribution and dominates at higher depths obscuring information from deep within the sample. We present an approach a simple geometry, called spatially-offset optical coherence tomography (SO-OCT), allowing singly scattered photons from depth to be retrieved whilst suppressing the presence of multiply scattered photons (speckle). Therefore, it improves signal detection to enhance the image contrast at depth in the presence of strong scattering samples. An approximately two-fold enhancement in image contrast at depths can be observed in different biological samples, such as zebrafish and krill. This approach solely requires the translation of a single lens in the experimental OCT arrangement to achieve enhancement on both image quality and depth penetration.
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