  We demonstrate that simultaneous application of optical clearing agents
(OCAs) and complex wavefront shaping in optical coherence tomography (OCT) can
provide significant enhancement of the penetration depth and imaging quality.
OCA reduces optical inhomogeneity of a highly scattering sample, and the
wavefront shaping of illumination light controls multiple scattering, resulting
in an enhancement of the penetration depth and signal-to-noise ratio. A tissue
phantom study shows that concurrent applications of OCA and wavefront shaping
successfully operate in OCT imaging. The penetration depth enhancement is
further demonstrated for ex vivo mouse ears, revealing hidden structures
inaccessible with conventional OCT imaging.
