  Imaging an object embedded within a scattering medium requires the correction
of complex sample-induced wave distortions. Existing approaches have been
designed to resolve them by optimizing signal waves recorded in each 2D image.
Here, we present a volumetric image reconstruction framework that merges two
fundamental degrees of freedom, the wavelength and propagation angles of light
waves, based on the object momentum conservation principle. On this basis, we
propose methods for exploiting the correlation of signal waves from volumetric
images to better cope with multiple scattering. By constructing experimental
systems scanning both wavelength and illumination angle of the light source, we
demonstrated a 32-fold increase in the use of signal waves compared with that
of existing 2D-based approaches and achieved ultrahigh volumetric resolution
(lateral resolution: 0.41 um, axial resolution: 0.60 um) even within complex
scattering medium owing to the optimal coherent use of the extremely broad
spectral bandwidth (225 nm).
